A Marwin 40m long Alumax CNC twin-gantry milling machine, used for 'prepping' wing stringers, has been retrofitted with a user-friendly contouring CNC capable of controlling up to 13 axes
The 40m long by 3m wide bed of the Marwin Alumax CNC twin-gantry milling machine located in Hangar 14 on the 800 acre Cambridge site of Marshall Aerospace enables 'prepping' operations to be carried out on aircraft stringers up to 22m in length. Purchased initially as two separate machines, which were then dismantled, moved and re-installed as one machine by Electron Engineering Services, a Heidenhain-approved TNC retrofitter, this refurbished machine is playing a key role in the supply of 11,700 stringers destined for the Airbus range of aircraft.
This is under the terms of an initial two-year contract with CAV Aerospace that requires the Manufacturing 3rd Party Department of Marshall Aerospace to hold buffer stocks of 'prepped' stringers ready for supply to the Tier One supplier.
According to Colin Flack, business development manager (Manufacturing), it became a 'race against' time to complete both the extensive hangar refurbishment and the commissioning of the re-manufactured gantry mill.
In fact, the entire project was completed within the 24 week deadline, with the official opening taking place as planned in October 2006.
Since then, Hanger 14 has become home to several thousand 'prepped' stringers as well as to a sizeable quantity of free issue material and, says Colin Flack, the expectation is that the sizeable order from CAV Aerospace will be the precursor to further support work in the future.
Refurbishment of the gantry mill by Halifax-based EES involved the replacement of an obsolete Allen Bradley control with a Heidenhain iTNC 530 contouring control capable of controlling up to 13 axes.
This has been fitted into a new cabinet on the first travelling gantry, which is equipped with two spindle heads.
A new, heavy-duty, 40kW spindle complete with chiller unit carries a large indexable-insert face mill that machines the upper and lower faces of stringers, with a 3.4mm depth of cut on the first X-axis pass over the work piece and a 0.8mm depth of cut on the return pass completing the milling of each face.
A second Gamfior high speed spindle, which can also swivel (A axis) through +/-20 deg, traverses the Y-axis to machine profiles on the stringer, as and when required.
EES is one of Europe's leading machine tool CNC retrofit and refurbishment specialists, and its recommendation of the Heidenhain iTNC 530 CNC was accepted after in-depth discussions with Marshall Aerospace.
This was on the basis that future 'prepping' work involving more complex shapes and profiles will require a significant five-axis capability.
The intention is to equip the second travelling gantry, which has still to be refurbished, with two five-axis spindle heads that will be under the control of a second iTNC 530 CNC.
Operators report that the new control is extremely user-friendly, although Colin Flack says current machining operations are not especially complex.
Longer term, however, the decision to install the Heidenhain CNCs is regarded by Marshall Aerospace as essential to the cost-effective production of highly accurate, complex workpiece contours machined in the shortest possible time.
The iTNC's short block processing time of 0.5ms for a 3D line segment without tool compensation permits fast traversing speeds, even on complex contours, and with its optimised tool path control, pre-calculation of the contour, and algorithms for 'jerk limitation', it ensures that the end result is a perfect mirror surface finish.
According to Heidenhain, this reflects the fact that for more than 20 years TNC contouring controls have been proving themselves in daily use on milling, drilling and boring machines and machining centres.
The iTNC 530 is the latest version and features a more powerful processor architecture.
However, like its predecessors, the iTNC 530 is both easy to use and flexible as it can be programmed remotely on a CAD/CAM system or on the shopfloor, with complex programs verified quickly and simply by way of the control's optimised graphics build-up.
http://www.manufacturingtalk.com/news/hei/hei156.html
Sunday, February 17, 2008
Retrofitting CNC Machining Center With Auxiliary High RPM Spindle Adds Greater Productivity And Flexibility
Adding a high-speed electric-spindle system to an existing CNC vertical machining center can improve the machine's productivity by providing quick, infinitely variable speed selection and higher rpm capabilities. Integrating the auxiliary spindle permanently onto the machine allows a company to meet the constantly changing demands of machining fine details and still retain the main spindle's capabilities for larger cutters.
In a typical application, one company recently purchased a five-axis Fadal VMC 4020 vertical machining center and modified it so it could also be used for machining fluidic circuit prototypes. Modifications include a Precise SC 102-O high speed electric spindle system (Precise Corp., Racine, Wisconsin), a special mounting plate that allows the spindle to remain in place while the main spindle is in use, some tool changer and programming adaptations, and cable carriers to keep all fluid and electrical lines neat and manageable.
The high rpm capability makes it possible to use carbide end mills from as small as 0.009" diameter up to about 1/4-inch. To make the high spindle rpm needed for small diameter cutters readily available, the auxiliary Precise spindle is mounted permanently on the side of the machine's column. Offset approximately ten inches, the spindle's fixed location enables it to be programmed into operations with little or no special accommodation. The machine's main spindle remains intact to provide the higher power and lower speed range needed to use larger diameter cutters.
With the auxiliary spindle, tools are set up in their own quickchange toolholders. This makes it possible to preset all of the tools and quickly change from tool to tool as needed, roughing with a larger diameter end mill for part of the program and finishing with smaller diameter end mills.
The machine can be programmed so switching from the main spindle to the high speed spindle can be done quickly, without interruption. When the operator specifies a speed above the main spindle's 10,000 rpm limit, the custom postprocessor recognizes the condition and applies the fixture offset, negates the main spindle, turns on the auxiliary spindle, turns it off when the cycle is through and returns to the main spindle.
The Precise spindle is equipped for automatic tool changing but the toolholder release can also be operated manually. A conveniently located pushbutton that releases the toolholder is tied to a zero-speed sensor so the tool will not be released until the operator is ready. Pre-set tooling allows the cutters to be changed quickly.
http://www.mmsonline.com/articles/0995bp3.html
In a typical application, one company recently purchased a five-axis Fadal VMC 4020 vertical machining center and modified it so it could also be used for machining fluidic circuit prototypes. Modifications include a Precise SC 102-O high speed electric spindle system (Precise Corp., Racine, Wisconsin), a special mounting plate that allows the spindle to remain in place while the main spindle is in use, some tool changer and programming adaptations, and cable carriers to keep all fluid and electrical lines neat and manageable.
The high rpm capability makes it possible to use carbide end mills from as small as 0.009" diameter up to about 1/4-inch. To make the high spindle rpm needed for small diameter cutters readily available, the auxiliary Precise spindle is mounted permanently on the side of the machine's column. Offset approximately ten inches, the spindle's fixed location enables it to be programmed into operations with little or no special accommodation. The machine's main spindle remains intact to provide the higher power and lower speed range needed to use larger diameter cutters.
With the auxiliary spindle, tools are set up in their own quickchange toolholders. This makes it possible to preset all of the tools and quickly change from tool to tool as needed, roughing with a larger diameter end mill for part of the program and finishing with smaller diameter end mills.
The machine can be programmed so switching from the main spindle to the high speed spindle can be done quickly, without interruption. When the operator specifies a speed above the main spindle's 10,000 rpm limit, the custom postprocessor recognizes the condition and applies the fixture offset, negates the main spindle, turns on the auxiliary spindle, turns it off when the cycle is through and returns to the main spindle.
The Precise spindle is equipped for automatic tool changing but the toolholder release can also be operated manually. A conveniently located pushbutton that releases the toolholder is tied to a zero-speed sensor so the tool will not be released until the operator is ready. Pre-set tooling allows the cutters to be changed quickly.
http://www.mmsonline.com/articles/0995bp3.html
Retrofit CNC converts lathe into user-friendliness
A retrofitted CNC has transformed an ageing, 'difficult-to-operate' manual lathe into a user-friendly, fully-functional CNC turning machine
By retrofitting an Anilam 4200T CNC to an ageing lathe, the UK Astronomy Technology Centre (ATC) has transformed what was 'a difficult-to-operate piece of equipment that technicians were hesitant to use' into a user-friendly, fully-functional CNC turning machine. As a result, CNC turning with the Anilam control is now the preferred route for two-axis turning at the centre.
Reflecting on the problems caused by the old controller Ewan Marshall, project technician at the Royal Observatory, Edinburgh ATC, says 'Despite the fact that all the turning work is fairly straightforward two-axis machining, the old control was difficult to program, therefore it was not the most cost-effective method to manufacture the components, resulting in the machine not being used to its full potential.' Today, however, after Anilam's local agent, Inscot, retrofitted the 4200T, ATC engineers have at their disposal a powerful yet user-friendly (full-screen editing and conversational help menu) CNC system featuring G code input with full text editor for cut, paste, search and replace, for example, plus interactive conversational G code help graphics and CAM programming.
Program utilities on the 4200T include create, delete/undelete, list, copy, rename and print, and the system also features constant surface speed as standard, to help guarantee consistent surface finish and extended tool life.
Also, the control can run in several operational modes - including teach mode achieved via single or dual handwheel operation with dual axis interpolation.
Being well-versed in G code programming, the ATC operators describe the Anilam as a vast improvement compared to the former control, as technician George Davidson confirms: 'In comparison to the previous CNC, which was a real nightmare, the Anilam guides us through everything.
We have extensive G code experience, so we tend to code in the job as we see it, rather than drawing it on the screen first.
'The Anilam CNC is really easy-to-use, so much so that the machine is now in more frequent use across a range of parts - which wasn't the case previously.' One example of the work being put through the new-look lathe is the beam steering mirror blanks required for the spectrometer focal plane unit within SPIRE (Spectral and Photometric Imaging Receiver), one of three instruments that will be carried on the European Space Agency's Herschel Space Observatory (formerly the Far Infra-Red and Sub-millimetre Telescope) scheduled for launch in 2007.
With its 3.5m primary mirror, it will be the biggest space telescope yet flown.
Designed for spectral and photometric observations at far infra-red and sub-millimetre wavelengths, SPIRE will investigate the statistics and physics of galaxy and structure formation in the early universe, and study the earliest stages of star formation.
SPIRE's focal plane unit - and therefore the mirror blanks - are critical components, and the blanks are rough and finish turned from 60mm diameter 6061 aluminium billets 90mm long before being switched to one of several milling machines-manual/DRO lathes for a variety of profile boring and milling, as well as part-off operations before being outsourced for diamond machining.
Machining includes the creation of a 'spectacle' feature and an opposing 'clamp' feature, as well as the production of a cavity face, various slots and the mirror face to an intermediate thickness of 10.55mm before diamond machining to create the mirror finish of 2 microns.
The turning and milling sequences are interspersed with two thermal cycling routines to stabilise the material structure for low temperature use.
With its mission 'to help keep the UK at the forefront of world astronomy by providing a UK focus for the design, production and promotion of state-of-the-art astronomical technology', the ATC shares the old Royal Observatory Edinburgh site at Blackford Hill with the Edinburgh University Institute for Astronomy, and with 11 employees the machine shop plays a key role in the manufacture of the various spectrometers, telescopes and infra-red cameras produced for customers the world over, including the Isaac Newton Group, UKIRT and Gemini telescopes.
No two projects are the same, so batch sizes through the machine shop are small - often one-offs - and Ewan Marshall says ATC is like every other manufacturing organisation in that each contract has to be competitively priced, produced on time and delivered to specification (even though ATC operates with Government funding and in a non-profitmaking mode).
As well as the impressive machine shop, ATC maintains its centre of excellence mantle via expert teams covering project science, project management, applied optics, and electronic and software engineering, and it invariably acts as the turnkey player in developing the specific solutions and designs (often in conjunction with universities at home and abroad) then determining and managing the appropriate manufacturing processes and lead time schedules.
Including administration, around 100 people are employed in the centre's CAD/CAM and electronic CAD, optical design, optical test laboratory, detector test facility and cleanroom, software development, machine shop, cryogenic and vacuum facilities, as well as the telescope simulator and fixture testing areas.
Many of the components produced are tested at -260deg and 25G before final commissioning on site by ATC staff.
The machine shop traditionally handles the production of all components within a 500mm3 envelope; anything larger that needs to be either machined or fabricated is outsourced along with specialist tasks such as gold plating and mirror-finish machining.
However, within the next few years the completion of a GBP 4 rebuilding project to create new workshops, laboratories and office space will enable ATC to handle larger projects, say up to 2 m3.
'There are no plans to extend our machining capacity,' says Ewan Marshall, 'rather, the expansion will enable us to cope more easily with the assembly and test of larger projects, through the construction of buildings with high-ceilings and heavy overhead cranes.' Most of the material processed by the machine shop is aluminium (in addition to lightness it exhibits good thermal characteristics at low temperatures), with stainless steel and copper processed in lesser quantities and, interestingly, each operator is held totally responsible for the complete machining and resulting quality of the components he produces.
Every technician can work across either the CNC milling machines (which all feature Heidenhain CNCs) or the manual/DRO and CNC lathes in addition to handling a myriad of inspection routines as well as operating the co-ordinate measuring machine and assimilating the resultant QC data.
Also, each technician will plan and manage the production route of 'his' components to align with the master production schedule.
Machining work is evenly split between turning and milling.
'So,' says Ewan Marshall in conclusion, 'the updating of the lathe with the Anilam CNC was met with a huge sigh of relief by everyone.
Nobody had wanted to use the machine, but after Anilam's recommended training session, we were all conversant and comfortable with the control.
We now confidently use the machine whenever we can.'
http://www.manufacturingtalk.com/news/aie/aie148.html
By retrofitting an Anilam 4200T CNC to an ageing lathe, the UK Astronomy Technology Centre (ATC) has transformed what was 'a difficult-to-operate piece of equipment that technicians were hesitant to use' into a user-friendly, fully-functional CNC turning machine. As a result, CNC turning with the Anilam control is now the preferred route for two-axis turning at the centre.
Reflecting on the problems caused by the old controller Ewan Marshall, project technician at the Royal Observatory, Edinburgh ATC, says 'Despite the fact that all the turning work is fairly straightforward two-axis machining, the old control was difficult to program, therefore it was not the most cost-effective method to manufacture the components, resulting in the machine not being used to its full potential.' Today, however, after Anilam's local agent, Inscot, retrofitted the 4200T, ATC engineers have at their disposal a powerful yet user-friendly (full-screen editing and conversational help menu) CNC system featuring G code input with full text editor for cut, paste, search and replace, for example, plus interactive conversational G code help graphics and CAM programming.
Program utilities on the 4200T include create, delete/undelete, list, copy, rename and print, and the system also features constant surface speed as standard, to help guarantee consistent surface finish and extended tool life.
Also, the control can run in several operational modes - including teach mode achieved via single or dual handwheel operation with dual axis interpolation.
Being well-versed in G code programming, the ATC operators describe the Anilam as a vast improvement compared to the former control, as technician George Davidson confirms: 'In comparison to the previous CNC, which was a real nightmare, the Anilam guides us through everything.
We have extensive G code experience, so we tend to code in the job as we see it, rather than drawing it on the screen first.
'The Anilam CNC is really easy-to-use, so much so that the machine is now in more frequent use across a range of parts - which wasn't the case previously.' One example of the work being put through the new-look lathe is the beam steering mirror blanks required for the spectrometer focal plane unit within SPIRE (Spectral and Photometric Imaging Receiver), one of three instruments that will be carried on the European Space Agency's Herschel Space Observatory (formerly the Far Infra-Red and Sub-millimetre Telescope) scheduled for launch in 2007.
With its 3.5m primary mirror, it will be the biggest space telescope yet flown.
Designed for spectral and photometric observations at far infra-red and sub-millimetre wavelengths, SPIRE will investigate the statistics and physics of galaxy and structure formation in the early universe, and study the earliest stages of star formation.
SPIRE's focal plane unit - and therefore the mirror blanks - are critical components, and the blanks are rough and finish turned from 60mm diameter 6061 aluminium billets 90mm long before being switched to one of several milling machines-manual/DRO lathes for a variety of profile boring and milling, as well as part-off operations before being outsourced for diamond machining.
Machining includes the creation of a 'spectacle' feature and an opposing 'clamp' feature, as well as the production of a cavity face, various slots and the mirror face to an intermediate thickness of 10.55mm before diamond machining to create the mirror finish of 2 microns.
The turning and milling sequences are interspersed with two thermal cycling routines to stabilise the material structure for low temperature use.
With its mission 'to help keep the UK at the forefront of world astronomy by providing a UK focus for the design, production and promotion of state-of-the-art astronomical technology', the ATC shares the old Royal Observatory Edinburgh site at Blackford Hill with the Edinburgh University Institute for Astronomy, and with 11 employees the machine shop plays a key role in the manufacture of the various spectrometers, telescopes and infra-red cameras produced for customers the world over, including the Isaac Newton Group, UKIRT and Gemini telescopes.
No two projects are the same, so batch sizes through the machine shop are small - often one-offs - and Ewan Marshall says ATC is like every other manufacturing organisation in that each contract has to be competitively priced, produced on time and delivered to specification (even though ATC operates with Government funding and in a non-profitmaking mode).
As well as the impressive machine shop, ATC maintains its centre of excellence mantle via expert teams covering project science, project management, applied optics, and electronic and software engineering, and it invariably acts as the turnkey player in developing the specific solutions and designs (often in conjunction with universities at home and abroad) then determining and managing the appropriate manufacturing processes and lead time schedules.
Including administration, around 100 people are employed in the centre's CAD/CAM and electronic CAD, optical design, optical test laboratory, detector test facility and cleanroom, software development, machine shop, cryogenic and vacuum facilities, as well as the telescope simulator and fixture testing areas.
Many of the components produced are tested at -260deg and 25G before final commissioning on site by ATC staff.
The machine shop traditionally handles the production of all components within a 500mm3 envelope; anything larger that needs to be either machined or fabricated is outsourced along with specialist tasks such as gold plating and mirror-finish machining.
However, within the next few years the completion of a GBP 4 rebuilding project to create new workshops, laboratories and office space will enable ATC to handle larger projects, say up to 2 m3.
'There are no plans to extend our machining capacity,' says Ewan Marshall, 'rather, the expansion will enable us to cope more easily with the assembly and test of larger projects, through the construction of buildings with high-ceilings and heavy overhead cranes.' Most of the material processed by the machine shop is aluminium (in addition to lightness it exhibits good thermal characteristics at low temperatures), with stainless steel and copper processed in lesser quantities and, interestingly, each operator is held totally responsible for the complete machining and resulting quality of the components he produces.
Every technician can work across either the CNC milling machines (which all feature Heidenhain CNCs) or the manual/DRO and CNC lathes in addition to handling a myriad of inspection routines as well as operating the co-ordinate measuring machine and assimilating the resultant QC data.
Also, each technician will plan and manage the production route of 'his' components to align with the master production schedule.
Machining work is evenly split between turning and milling.
'So,' says Ewan Marshall in conclusion, 'the updating of the lathe with the Anilam CNC was met with a huge sigh of relief by everyone.
Nobody had wanted to use the machine, but after Anilam's recommended training session, we were all conversant and comfortable with the control.
We now confidently use the machine whenever we can.'
http://www.manufacturingtalk.com/news/aie/aie148.html
CNC Retrofit For Boring Mills - Vega MLM-B Mill CNC
The Vega MLM-B Mill CNC was specifically designed as a retrofit package for older boring mills. Combining the manual operations that operators want with thc automatic cycles and full 3D CNC programming, this new CNC is just what shops need to rejuvenate their older machines and remain competitive in today's market, the company says.
The CNC is easy to use and learn, which lowers the learning curve, making operators productive right away. It has a host of features, including handwheel, joystick and pushbutton jog interfaces, manual tapping, programmable cycles, mirroring, scaling, and many other features that help reduce setup time, improve quality and reduce scrap.
Additional standard features include a color LCD display, 32-bit CPU, hard disk, floppy disk, CD ROM, hand held pendant, full keyboard and a user-friendly keyboard.
The retrofit package includes on-site installation and operator training and usually takes 7-15 days. The Vega MLM-B can interface with both AC and DC servo systems, which means that current motors and drives don't have to be replaced. This reduces typical retrofit costs by as much as 40 percent.
http://findarticles.com/p/articles/mi_m3101/is_6_74/ai_79900939
The CNC is easy to use and learn, which lowers the learning curve, making operators productive right away. It has a host of features, including handwheel, joystick and pushbutton jog interfaces, manual tapping, programmable cycles, mirroring, scaling, and many other features that help reduce setup time, improve quality and reduce scrap.
Additional standard features include a color LCD display, 32-bit CPU, hard disk, floppy disk, CD ROM, hand held pendant, full keyboard and a user-friendly keyboard.
The retrofit package includes on-site installation and operator training and usually takes 7-15 days. The Vega MLM-B can interface with both AC and DC servo systems, which means that current motors and drives don't have to be replaced. This reduces typical retrofit costs by as much as 40 percent.
http://findarticles.com/p/articles/mi_m3101/is_6_74/ai_79900939
CNC Retrofits Answer Scarcity Of Manual Machinists
By retrofitting CNCs to three manual Hardinge lathes, Mansfield Screw Machine Products Co. (Lexington, Ohio) increased the throughput on these machines by about 15 percent. That's the estimate of shop floor supervisor Keith Reed, who performed the retrofits, and now writes the machines' NC programs. But improving performance was not the main reason for the retrofits; the machines were always productive. Instead, retrofitting was a way to keep them productive, even without an experienced machinist in control. That became important when one of the company's best Hardinge operators retired. "We just can't find machinists with those skills anymore," Mr. Reed says. So the company purchased retrofit kits from OmniTurn (Farmingdale, New York), a supplier offering these kits for a variety of Hardinge lathes.
Now, the upgraded machines run more productively. The underlying lathes were all over ten years old. With the newer, more rigid axis drives, the machines cut accurately at higher speeds and feedrates than the previous drives would permit. At the same time, there is now far less time lost to manual toolchanges. The retrofit kit includes a gang tooling system allowing the machine to employ several tools in one cycle, like almost any CNC lathe. And because the machines are now NC, they deliver these performance gains regardless of the skill level of the operator.
The retrofitted machines also improve the efficiency of the shop's process overall. A part featuring a surface finish requirement of 15 microinches illustrates this. Using the manual machines, the shop couldn't hold this finish consistently, so bench work was needed. But since the retrofit, "those parts come off of the lathes smooth enough to ship," Mr. Reed says. Benching has been eliminated.
For other parts, savings come from eliminating expensive time on more costly machines. Like many automatic machining contractors, Mansfield Screw Machine uses CNC equipment for secondary operations. However, to provide customers with just-in-time delivery, this shop routinely runs blanks in large volumes on the automatic machines, then performs the CNC machining in small batches, to complete the parts only as the customer needs them. But now there is an alternative to higher-end CNC equipment for some of this work. The retrofitted lathes have the capability to perform many of the same complex machining routines as a full CNC lathe, including single-point threading.
The retrofit kits came largely pre-assembled. Working with an electrician, Mr. Reed performed each retrofit in about a day and a half. He writes the NC programs for these machines on a PC at his desk, using software which also came with the kit. Once the program is written and the correct tools are loaded, he says, the operator's only role is to load each workpiece, start the cycle, and check parts against the specification.
This simplicity, combined with the efficiency gains, has convinced Mr. Reed that CNC retrofitting was the right investment to make. At least one other manual Hardinge lathe operator in the shop is nearing retirement, he says. "And when he goes, I think we'll retrofit two more machines."
http://www.mmsonline.com/articles/0598bp1.html
Now, the upgraded machines run more productively. The underlying lathes were all over ten years old. With the newer, more rigid axis drives, the machines cut accurately at higher speeds and feedrates than the previous drives would permit. At the same time, there is now far less time lost to manual toolchanges. The retrofit kit includes a gang tooling system allowing the machine to employ several tools in one cycle, like almost any CNC lathe. And because the machines are now NC, they deliver these performance gains regardless of the skill level of the operator.
The retrofitted machines also improve the efficiency of the shop's process overall. A part featuring a surface finish requirement of 15 microinches illustrates this. Using the manual machines, the shop couldn't hold this finish consistently, so bench work was needed. But since the retrofit, "those parts come off of the lathes smooth enough to ship," Mr. Reed says. Benching has been eliminated.
For other parts, savings come from eliminating expensive time on more costly machines. Like many automatic machining contractors, Mansfield Screw Machine uses CNC equipment for secondary operations. However, to provide customers with just-in-time delivery, this shop routinely runs blanks in large volumes on the automatic machines, then performs the CNC machining in small batches, to complete the parts only as the customer needs them. But now there is an alternative to higher-end CNC equipment for some of this work. The retrofitted lathes have the capability to perform many of the same complex machining routines as a full CNC lathe, including single-point threading.
The retrofit kits came largely pre-assembled. Working with an electrician, Mr. Reed performed each retrofit in about a day and a half. He writes the NC programs for these machines on a PC at his desk, using software which also came with the kit. Once the program is written and the correct tools are loaded, he says, the operator's only role is to load each workpiece, start the cycle, and check parts against the specification.
This simplicity, combined with the efficiency gains, has convinced Mr. Reed that CNC retrofitting was the right investment to make. At least one other manual Hardinge lathe operator in the shop is nearing retirement, he says. "And when he goes, I think we'll retrofit two more machines."
http://www.mmsonline.com/articles/0598bp1.html
Retrofit Using Six-Axis DRO Offers Flexibility
Following a retrofit using Heidenhain's (Schaumburg, Illinois) Positip 880 six-axis readout on a partial machine rebuild of a vertical milling/boring machine, UKAEA Fusion Special Purposes Workshop in England is now benefiting from greater flexibility on existing machinery.
The BOKO WF1 vertical milling machine has been a machine shop favorite because of its integrated rotary table, swivelling head and Z-axis capacity from either the head or quill. This translates to four axes of linear movement and two rotary axes.
Retrofitting an encoder to the rotary table allows the rotary movement of the table to be shown on the readout, which offers greater positional accuracy and ease of positioning. On the BOKO, however, this usually requires the removal and re-engineering of the underside of the table to accept the encoder. When the Special Purposes Workshop of UKAEA Fusion decided to get some rebuild work and have a new five-axis readout fitted to its 20-year-old machine, Eric Clarke from Promtech Services (Milton Keynes, United Kingdom), Heidenhain's regional retrofit distributor in the United Kingdom, suggested a new approach. This approach incorporates an encoder retrofitted to the end of the rotary table's worm gear, combined with some reworking of the existing worm gear to remove excessive backlash.
“We are now positioning the rotary table to within 5 arcseconds, with backlash of less than 10 arcseconds,” comments Dave Langridge, workshop supervisor at UKAEA. “A recent job involved 40 holes around a flange at a nine-degree pitch angle. Having the angular display on the readout made the job much quicker to produce.” Mr. Langridge described the ability to sum both the head and quill movements into one Z-axis display, which allows either the head or the quill to be used without losing the Z-axis display value, as “fantastic.”
Specializing in R&D work for the fusion research program worldwide, the Special Purposes Workshop provides the machining expertise for the UKAEA (Fusion) Special Techniques Group based at the Culham Science Center near Abingdon. Gordon Harrison is the manager of the Special Purposes Workshop.
“Promtech had previously undertaken two Bridgeport Interact CNC upgrades with Heidenhain controls—both with four-axis capability,” Mr. Harrison says. “This gave us the confidence in its ability to undertake the work on the BOKO that has now returned the machine to ‘as good as new' condition with the retrofit, adding more flexibility in the type of work undertaken on the machine. This helps us to be competitive in bidding for work in our specialist field.”
http://www.mmsonline.com/articles/0305bp3.html
The BOKO WF1 vertical milling machine has been a machine shop favorite because of its integrated rotary table, swivelling head and Z-axis capacity from either the head or quill. This translates to four axes of linear movement and two rotary axes.
 |
| UKAEA Fusion Special Purposes Workshop's BOKO WF1 is more than 20 years old. Following the Positip 880 retrofit, the machine is said to be in “as good as new” condition. |
“We are now positioning the rotary table to within 5 arcseconds, with backlash of less than 10 arcseconds,” comments Dave Langridge, workshop supervisor at UKAEA. “A recent job involved 40 holes around a flange at a nine-degree pitch angle. Having the angular display on the readout made the job much quicker to produce.” Mr. Langridge described the ability to sum both the head and quill movements into one Z-axis display, which allows either the head or the quill to be used without losing the Z-axis display value, as “fantastic.”
Specializing in R&D work for the fusion research program worldwide, the Special Purposes Workshop provides the machining expertise for the UKAEA (Fusion) Special Techniques Group based at the Culham Science Center near Abingdon. Gordon Harrison is the manager of the Special Purposes Workshop.
“Promtech had previously undertaken two Bridgeport Interact CNC upgrades with Heidenhain controls—both with four-axis capability,” Mr. Harrison says. “This gave us the confidence in its ability to undertake the work on the BOKO that has now returned the machine to ‘as good as new' condition with the retrofit, adding more flexibility in the type of work undertaken on the machine. This helps us to be competitive in bidding for work in our specialist field.”
http://www.mmsonline.com/articles/0305bp3.html
Faster Milling Of EDM Electrodes With Retrofit CNC Package
Dana Heckendorf of D. Heck Tool LLC (Thompson, Connecticut), a precision moldmaker working out of his garage, wanted to compete with bigger shops that had Computer Numerical Control (CNC) equipment. This led him to consider retrofitting his manual Kent milling machine with a CNC retrofit package. With a Mitutoyo MillStar CNC from Mitutoyo Corp. (Aurora, Illinois), the shop owner can program the shape of a complex EDM electrode in 45 minutes and mill the part in 30 minutes. According to Mr. Heckendorf, the single electrode does the work of a dozen simpler ones that would take most of a day to mill or grind manually.
"Basically, we've boosted electrode throughput more than seven to one and streamlined our EDM die sinking as well," Mr. Heckendorf says. With two-axis CNC, the moldmaker quickly mills the more intricate electrodes he needs to cut mold cavities faster and with a better finish than before. Faster electrode milling and subsequent cavity cutting trimmed delivery time on what was a six-week job by seven days. "With the MillStar, I'm doing very high quality EDM electrodes in far less time," says Mr. Heckendorf.
D. Heck Tool specializes in prototype and small production molds for plastic parts. Much of the tooling produces tiny medical and switch components. The stainless and tool steel mold frames are generally about 8 inches square by 10 inches high. While mold cavities are usually cut by a Hansvedt 201 CNC EDM, the graphite electrodes used to cut the pockets must be milled.
The smallest electrodes used by D. Heck Tool are just 0.010 inch wide. "I could mill them manually," says Mr. Heckendorf, "but electrodes are very time consuming parts to make manually."
When Mr. Heckendorf started his business three years ago, he thought CNC conversion was the smart way to go. "It's hard to sell mold-making services without talking CNC," he says. "The first question they ask you is, `what do you have for CNC equipment?'"
Sophisticated computer control was a new endeavor for the small shop owner. As a lead moldmaker, Mr. Heckendorf had long made molds with a manual finish grinder and knew nothing about CNC programming. However, the milling machine he'd bought had a bolt-on power feed and Mitutoyo digital readout, so he spoke to his MTI representative about a new CNC retrofit package.
About a year ago, he upgraded his milling machine with the Mitutoyo MillStar control package. The expandable two-axis control promised the right capability, given the type of work to be done and the background of the user. "I knew I wanted a two-axis CNC because I had no hands-on experience programming," says Mr. Heckendorf.
Mr. Heckendorf visited surrounding job shops and tried several CNC packages. "The Mitutoyo package was one of the very few to run through Windows 95, which is an easy operating system to learn," he says. "It's also got good graphics and can be programmed in G-code or plain shop language."
In addition, canned cycles automate routine operations such as hole patterns, lines and arcs. More complex jobs are set up through drop-down menus on the 10-inch color screen. Function keys let the user override the automatic control and change feed rates and other parameters on the fly. Mr. Heckendorf was able to use the control after only four hours of instruction.
Precision EDM electrodes for cutting molds are milled to the shape of the finished plastic part. Customers typically supply Mr. Heckendorf with hard copy drawings of their molded parts. Mr. Heckendorf extrapolates electrode dimensions from the drawings allowing for plastic shrinkage, overburn, and other factors.
Most electrode jobs at D. Heck Tools are programmed in conversational mode. Programs stored in the MillStar memory or on disk also give D. Heck Tool repeatability difficult to achieve with manual operation.
The EDM uses the precision electrodes to cut mold contours within 0.0002 inch. Using more complicated electrodes closer to the shape of the finished part burns away more of the mold cavity faster and leaves better quality finishes.
One complex mold for a speedometer/tachometer case previously required 28 different electrodes that were set up and machined manually. By comparison, a similar gage case mold required just 12 electrodes milled under CNC. As a result, the typical six-week job was shortened by seven working days. For D. Heck Tool, the switch to CNC is paying off in shorter mold delivery times and lower costs.
Time saved in setup also means more effective use of the milling machine. Mr. Heckendorf estimates his milling machine actually ran just four days a month in the days of manual setups. Setup occupied the rest of the time. With CNC operation and stored programs, the same machine now makes chips three weeks a month, a great increase.
For a one-man shop in a competitive market, a CNC retrofit package has proven itself a powerful business advantage. "The control allows me to quote five weeks on a job someone else is quoting nine weeks on. That's what my business is built on," he says.
http://www.mmsonline.com/articles/0599bp1.html
"Basically, we've boosted electrode throughput more than seven to one and streamlined our EDM die sinking as well," Mr. Heckendorf says. With two-axis CNC, the moldmaker quickly mills the more intricate electrodes he needs to cut mold cavities faster and with a better finish than before. Faster electrode milling and subsequent cavity cutting trimmed delivery time on what was a six-week job by seven days. "With the MillStar, I'm doing very high quality EDM electrodes in far less time," says Mr. Heckendorf.
D. Heck Tool specializes in prototype and small production molds for plastic parts. Much of the tooling produces tiny medical and switch components. The stainless and tool steel mold frames are generally about 8 inches square by 10 inches high. While mold cavities are usually cut by a Hansvedt 201 CNC EDM, the graphite electrodes used to cut the pockets must be milled.
The smallest electrodes used by D. Heck Tool are just 0.010 inch wide. "I could mill them manually," says Mr. Heckendorf, "but electrodes are very time consuming parts to make manually."
When Mr. Heckendorf started his business three years ago, he thought CNC conversion was the smart way to go. "It's hard to sell mold-making services without talking CNC," he says. "The first question they ask you is, `what do you have for CNC equipment?'"
Sophisticated computer control was a new endeavor for the small shop owner. As a lead moldmaker, Mr. Heckendorf had long made molds with a manual finish grinder and knew nothing about CNC programming. However, the milling machine he'd bought had a bolt-on power feed and Mitutoyo digital readout, so he spoke to his MTI representative about a new CNC retrofit package.
About a year ago, he upgraded his milling machine with the Mitutoyo MillStar control package. The expandable two-axis control promised the right capability, given the type of work to be done and the background of the user. "I knew I wanted a two-axis CNC because I had no hands-on experience programming," says Mr. Heckendorf.
Mr. Heckendorf visited surrounding job shops and tried several CNC packages. "The Mitutoyo package was one of the very few to run through Windows 95, which is an easy operating system to learn," he says. "It's also got good graphics and can be programmed in G-code or plain shop language."
In addition, canned cycles automate routine operations such as hole patterns, lines and arcs. More complex jobs are set up through drop-down menus on the 10-inch color screen. Function keys let the user override the automatic control and change feed rates and other parameters on the fly. Mr. Heckendorf was able to use the control after only four hours of instruction.
Precision EDM electrodes for cutting molds are milled to the shape of the finished plastic part. Customers typically supply Mr. Heckendorf with hard copy drawings of their molded parts. Mr. Heckendorf extrapolates electrode dimensions from the drawings allowing for plastic shrinkage, overburn, and other factors.
Most electrode jobs at D. Heck Tools are programmed in conversational mode. Programs stored in the MillStar memory or on disk also give D. Heck Tool repeatability difficult to achieve with manual operation.
The EDM uses the precision electrodes to cut mold contours within 0.0002 inch. Using more complicated electrodes closer to the shape of the finished part burns away more of the mold cavity faster and leaves better quality finishes.
One complex mold for a speedometer/tachometer case previously required 28 different electrodes that were set up and machined manually. By comparison, a similar gage case mold required just 12 electrodes milled under CNC. As a result, the typical six-week job was shortened by seven working days. For D. Heck Tool, the switch to CNC is paying off in shorter mold delivery times and lower costs.
Time saved in setup also means more effective use of the milling machine. Mr. Heckendorf estimates his milling machine actually ran just four days a month in the days of manual setups. Setup occupied the rest of the time. With CNC operation and stored programs, the same machine now makes chips three weeks a month, a great increase.
For a one-man shop in a competitive market, a CNC retrofit package has proven itself a powerful business advantage. "The control allows me to quote five weeks on a job someone else is quoting nine weeks on. That's what my business is built on," he says.
http://www.mmsonline.com/articles/0599bp1.html
Profile follower burner can be CNC retrofitted
For those fabricators looking to move away from employing sub-contract plate profiling services, a co-ordinate gas cutting machine is being offered at a low 'entry level' price
For those fabricators looking to move away from employing sub-contract plate profiling services, the Ultrarex UXB co-ordinate gas cutting machine is being offered at 'entry level prices - an economical way of bringing plate profiling in-house. Esab Automation, Andover, said the machine has low capital investment cost, low maintenance needs, high speed cutting and precise guiding accuracy.
It is offered with photo-electric tracing or can be fitted with CNC.
Capacity is for cutting metals from 3mm to 200mm in thickness, depending upon the model purchased.
The tracer control system copies outlines or silhouettes on a 1:1 basis.
The drawings are not needed for linear cutting or rectangular bevelling of plates.
Up to four oxy-fuel gas torches can be fitted.
http://www.manufacturingtalk.com/news/eab/eab101.html
For those fabricators looking to move away from employing sub-contract plate profiling services, the Ultrarex UXB co-ordinate gas cutting machine is being offered at 'entry level prices - an economical way of bringing plate profiling in-house. Esab Automation, Andover, said the machine has low capital investment cost, low maintenance needs, high speed cutting and precise guiding accuracy.
It is offered with photo-electric tracing or can be fitted with CNC.
Capacity is for cutting metals from 3mm to 200mm in thickness, depending upon the model purchased.
The tracer control system copies outlines or silhouettes on a 1:1 basis.
The drawings are not needed for linear cutting or rectangular bevelling of plates.
Up to four oxy-fuel gas torches can be fitted.
http://www.manufacturingtalk.com/news/eab/eab101.html
CNC Retrofits Answer Scarcity Of Manual Machinists
By retrofitting CNCs to three manual Hardinge lathes, Mansfield Screw Machine Products Co. (Lexington, Ohio) increased the throughput on these machines by about 15 percent. That's the estimate of shop floor supervisor Keith Reed, who performed the retrofits, and now writes the machines' NC programs. But improving performance was not the main reason for the retrofits; the machines were always productive. Instead, retrofitting was a way to keep them productive, even without an experienced machinist in control. That became important when one of the company's best Hardinge operators retired. "We just can't find machinists with those skills anymore," Mr. Reed says. So the company purchased retrofit kits from OmniTurn (Farmingdale, New York), a supplier offering these kits for a variety of Hardinge lathes.
Now, the upgraded machines run more productively. The underlying lathes were all over ten years old. With the newer, more rigid axis drives, the machines cut accurately at higher speeds and feedrates than the previous drives would permit. At the same time, there is now far less time lost to manual toolchanges. The retrofit kit includes a gang tooling system allowing the machine to employ several tools in one cycle, like almost any CNC lathe. And because the machines are now NC, they deliver these performance gains regardless of the skill level of the operator.
The retrofitted machines also improve the efficiency of the shop's process overall. A part featuring a surface finish requirement of 15 microinches illustrates this. Using the manual machines, the shop couldn't hold this finish consistently, so bench work was needed. But since the retrofit, "those parts come off of the lathes smooth enough to ship," Mr. Reed says. Benching has been eliminated.
For other parts, savings come from eliminating expensive time on more costly machines. Like many automatic machining contractors, Mansfield Screw Machine uses CNC equipment for secondary operations. However, to provide customers with just-in-time delivery, this shop routinely runs blanks in large volumes on the automatic machines, then performs the CNC machining in small batches, to complete the parts only as the customer needs them. But now there is an alternative to higher-end CNC equipment for some of this work. The retrofitted lathes have the capability to perform many of the same complex machining routines as a full CNC lathe, including single-point threading.
The retrofit kits came largely pre-assembled. Working with an electrician, Mr. Reed performed each retrofit in about a day and a half. He writes the NC programs for these machines on a PC at his desk, using software which also came with the kit. Once the program is written and the correct tools are loaded, he says, the operator's only role is to load each workpiece, start the cycle, and check parts against the specification.
This simplicity, combined with the efficiency gains, has convinced Mr. Reed that CNC retrofitting was the right investment to make. At least one other manual Hardinge lathe operator in the shop is nearing retirement, he says. "And when he goes, I think we'll retrofit two more machines.
http://www.productionmachining.com/articles/mms014.html
Now, the upgraded machines run more productively. The underlying lathes were all over ten years old. With the newer, more rigid axis drives, the machines cut accurately at higher speeds and feedrates than the previous drives would permit. At the same time, there is now far less time lost to manual toolchanges. The retrofit kit includes a gang tooling system allowing the machine to employ several tools in one cycle, like almost any CNC lathe. And because the machines are now NC, they deliver these performance gains regardless of the skill level of the operator.
The retrofitted machines also improve the efficiency of the shop's process overall. A part featuring a surface finish requirement of 15 microinches illustrates this. Using the manual machines, the shop couldn't hold this finish consistently, so bench work was needed. But since the retrofit, "those parts come off of the lathes smooth enough to ship," Mr. Reed says. Benching has been eliminated.
For other parts, savings come from eliminating expensive time on more costly machines. Like many automatic machining contractors, Mansfield Screw Machine uses CNC equipment for secondary operations. However, to provide customers with just-in-time delivery, this shop routinely runs blanks in large volumes on the automatic machines, then performs the CNC machining in small batches, to complete the parts only as the customer needs them. But now there is an alternative to higher-end CNC equipment for some of this work. The retrofitted lathes have the capability to perform many of the same complex machining routines as a full CNC lathe, including single-point threading.
The retrofit kits came largely pre-assembled. Working with an electrician, Mr. Reed performed each retrofit in about a day and a half. He writes the NC programs for these machines on a PC at his desk, using software which also came with the kit. Once the program is written and the correct tools are loaded, he says, the operator's only role is to load each workpiece, start the cycle, and check parts against the specification.
This simplicity, combined with the efficiency gains, has convinced Mr. Reed that CNC retrofitting was the right investment to make. At least one other manual Hardinge lathe operator in the shop is nearing retirement, he says. "And when he goes, I think we'll retrofit two more machines.
http://www.productionmachining.com/articles/mms014.html
Choosing A Retrofit CNC
Intel co-founder Gordon Moore predicted the growth rate which now bears his name. Moore's Law suggests that the state of the art in computer processing power will double every 18 months.
This exponential pace of development affects computers everywhere. But on the floor of a machine shop, the impact is particularly striking. Here, rapidly evolving computer numerical controls (CNCs) meet machine tools whose basic structures have changed little since before these controls were introduced. The lopsided rate of change often means that the machine tool remains mechanically sound and serviceable long after its control has been eclipsed by newer models. There is no Moore's Law for the iron. As a result, some shops find themselves saddled with inoperative machines, idled only because the control is obsolete and replacement components can no longer be found. Still more shops use CNC machines whose mechanical structures could be employed much more effectively if only the controls had access to the power and features of more recently developed models. In each of these cases, one option is to scrap the old machine in favor of an entirely new one, with its own new control. However, another option is to retain the mechanical structure, and retrofit a replacement CNC.
Conserving the iron in this way is not always the more economical choice. CNCs are not simply plug-in devices. Any combination of CNC and machine tool is in fact a carefully engineered system, and the work of integrating this system is typically more expensive than the CNC itself. A new, mass-produced machine tool carries almost none of this engineering cost. The OEM spreads the one-time expense for system integration across the entire run of that machine. That option is not available for most retrofit jobs, where the "production run" typically amounts to just one unit.
Because of this integration expense and its effect on overall cost, many shops don't even consider CNC retrofitting. And perhaps rightly so; retrofitting instead of buying new is still cost-effective only for a minority of machine tools. However, retrofitting today may be worth a second look. The economics have changed significantly, even in just the last five years. There is an expanded range of choices among retrofit CNCs, and this has produced an expanded range of machine tools for which retrofitting now makes sense.
CNC
Today, two things can be said of the CNC retrofit market:
1. Machines that were once too old to justify a CNC retrofit now make excellent candidates.
2. Machines that were once too new to justify a CNC retrofit also make excellent candidates.
In the case of the older machines, today's controls are more forgiving of ballscrew error, backlash, way friction and other symptoms of mechanical wear. By compensating electronically for these errors, the right CNC alone may be enough to return a worn machine to like-new precision. Thus, the retrofit may not have to include costs for replacement bearings, ballscrews, or gearing, or for scraping the ways or other mechanical service.
In the case of the newer machines, recent improvements in control technology can make a more recent or more specialized CNC far more productive for the machine than its standard control unit, even when that older control is still functioning well. The retrofit CNC may offer important capabilities the standard one does not, including:
* High-feed rate, high-accuracy machining, particularly during contour milling. This can be the result of features including look-ahead, faster servo updates, and curve interpolation. It can also be the result of expanded program storage capacity or faster data transmission across a network.
* The ability to run third-party PC software directly on the control, for functions like shopfloor programming, or updating machining offsets based on trends in SPC data.
* Data exchange with networked PCs. Fast, two-way data transfer not only enables the CNC to obtain a part program quickly from a remote source, but can also let a remote PC monitor and react to the machine's status.
CNC Retrofit
Most of these benefits are products of increased computing power (a la Moore's Law), which has expanded the choices available to control buyers by allowing CNCs to deliver more sophisticated and specialized functions. However, there is another factor spurring CNC development. Some features, like memory and networking improvements, have grown from the low-cost platform now available thanks to the spread of non-proprietary, commodity PC hardware. And this PC hardware has also produced more choices, as different CNC vendors apply the hardware in different ways.
If you are shopping for a replacement control, should you choose one that is in some way PC-based or PC-interfaced? Today there is a good chance the answer is yes.
But does this mean you should favor the control that includes the most off-the-shelf PC hardware? Not necessarily.
No, the best way to choose a replacement CNC in today's market is to take advantage of the range of choice now available to find the right control for the application. This will mean selecting the one that best delivers the features—including price—which that application demands. However, it will also mean finding the most appropriate mix of proprietary and non-proprietary hardware.
Not "Either/Or"
There are varying degrees to which a control can employ widely available hardware. Thus "proprietary" and "non-proprietary" are not either/or conditions. They can better be imagined as opposite directions along a common axis.
At the extreme "proprietary" end of this axis would be the CNC which was essentially the only type available ten years ago. This control has hardware built or specified entirely by the manufacturer, and at best offers only a slow serial interface for (one-way) data exchange.
PC-based Control
PC-based Control
PC-based Control
PC-based Control
A PC front end can bring networking, memory, and third-party software benefits to a control system that still offers the advantages of single-source hardware. Illustration courtesy GE Fanuc.
Today, at or near the opposite end of this axis would be a control like the one offered by Manufacturing Data Systems, Inc. (MDSI; Ann Arbor, Michigan). Designed to permit a low-cost retrofit, or low-cost entry into CNC networking, MDSI's control consists of PC software running entirely on non-proprietary hardware. Its hardware requirements include a touch-screen monitor, and interface cards for encoders, servos, and I/O, all of which can be purchased from any of a variety of vendors. It has no motion control card. Instead, it closes the servo loop via algorithms in the software. For this reason, it requires just a digital-to-analog converter to interface with the servomotors.
Between these two extremes would be a CNC like the one offered by Creative Technology Corporation (Arlington Heights, Illinois). This is a control optimized to serve the needs of shops interested in milling intricate contoured forms at high feed rates. These include makers of molds, dies, and prototype parts. Accordingly, this PC-based control employs one particular vendor's motion control card, chosen for its fast servo cycle time, among other features. While this single-source card technically qualifies as proprietary hardware, the overall control is not as proprietary as the "extreme" proprietary control cited above. The customer does not have to return to the control vendor for replacement parts or upgrades. The maker of the motion control card has licensed the right to produce and market its hardware to a variety of competing manufacturers, and the rest of the control consists of generic PC hardware that is widely available.
This leads to another frequently used CNC term necessary to carry this discussion further. That term is open. (As in, "open architecture.") It is used together with "PC-based" so often that the two may appear identical in meaning. However, while the definitions may overlap, these two terms describe very different ideas.
In fact, different CNC vendors embrace any of at least two definitions for an open control. Some define this as a control using off-the-shelf hardware, which therefore (in theory) can be maintained and upgraded inexpensively, without the vendor's involvement.
Other vendors view an open control as one that can easily share information across a network. This information includes both input, like an NC program, and output, like machine status data.
These two definitions of open don't necessarily go together. A CNC can be open to hardware without being open to a network, and a CNC favoring proprietary hardware can be constructed to interface with a network freely. In the retrofit world, one example of this second case comes from Memex Electronics (Burlington, Ontario, Canada), which offers retrofit boards allowing older, "closed" Fanuc CNCs to connect directly to a PC network.
However, a more general example of a system delivering network openness to a proprietary CNC comes from yet another approach to a control employing PC hardware. This is an approach offered by GE Fanuc (Charlottesville, Virginia) and Siemens (Elk Grove Village, Illinois), among others. These companies place a PC front end on a control system in which all hardware comes from a single source—from pushbuttons through servomotors. This is the PC-enabled control system that most resembles the traditional, proprietary CNC. And for this reason, it may be the right approach for many applications.
Costs And Benefits
The determining factor, according to both GE Fanuc and Siemens, is the productive value of the machine tool.
For example, the purpose of a CNC retrofit may be to give new life to a machine that is non-critical and/or relatively inexpensive. The machine may be one that sits idle because needed hardware for its dated control can no longer be found, or because the control itself limits the machine's capabilities or makes it difficult to use. The machine may also be a low-cost vertical machining center that a different control might make faster or more accurate. In any of these cases, the shop will likely see the productivity gain from a retrofit as "gravy"—extra machining capacity acquired for significantly less than the cost of buying a new machine. If so, then the shop has to minimize the cost of the retrofit to make the upgrade cost-effective. This means finding the most inexpensive control that is feasible, and this may well mean choosing one that maximizes its use of widely available electronics.
But as the value of the machine tool increases, the outlook may change. There is no precise dollar value at which a machine can no longer be said to be "low cost." However, somewhere on an ascending scale of the machine's replacement cost—whether this is $200,000, $300,000, $500,000—there comes a point where the machine is valuable enough, and machine downtime is costly enough, that a compelling case can be made for proprietary hardware. With a single-source control system, the shop has the support of just one vendor behind all of the electronics that keep this costly machine productive.
Siemens marketing manager Peter Herweck adds another consideration when evaluating a largely non-proprietary control versus a largely proprietary one. A common selling point of the former option is its promise to let the buyer upgrade the control without the vendor's involvement, just as one would upgrade an office PC. The more proprietary controls do not promise this same freedom. However, Mr. Herweck cautions potential CNC buyers to weigh how valuable this promise really is. Questions he would have them ask include: "How often will I really want to upgrade this control? Can I truly perform this upgrade more economically in-house? And if so, am I willing to trade the support advantages of a single-source control to realize these savings?"
As for the other selling points of a non-proprietary control, he notes that a more proprietary control can also deliver these. He lists them: "Expanded part program storage; freedom to run third-party software; and data I/O, whether this is networking, zip or floppy drive, or a PCMCIA slot. A single-source control with a PC front end can provide all of these advantages," he says. And while the single-source system adds the support benefits to this, he notes that it also delivers these benefits not through general-purpose hardware, but via hardware that has been engineered around one function—reliably and repeatably controlling a machine tool.
The argument, in other words, is that you get what you pay for. However, today's market offers a corollary to this: If you don't want to pay for the advantages of a proprietary system, you no longer have to. Both of the less-proprietary systems mentioned in this article illustrate this, albeit in different ways. Using MDSI's control, shops have not only "resurrected" machines that were once too low-cost to justify retrofitting, but in some cases have realized performance benefits—including accuracy at higher feed rates—which the original control never permitted. And the specialized focus of the Creative Technology control has allowed die-mold shops to devote the price of a CNC retrofit to maximizing the control features most beneficial to the die-mold milling application. In fact, the control's benefits have proven profitable enough in this application that some die-mold shops have not waited for obsolescence, but instead have retrofitted the control to practically new vertical machining centers.
Upgrades like these illustrate how CNC technology has evolved rapidly in recent years. As to where this evolution might lead, the answer may lie no farther (from me) than my own fingertips.
Look To The Office
I am writing this article on a word processor. By this I mean a generic PC running word processing software. One generation ago, another person doing my job would have used a typewriter. A little later, that same editor might have used one of the early versions of the word processor. This first word processor was not an "open" system, but instead a dedicated machine. Its built-in logic could be upgraded only through a costly hardware replacement.
CNC vendors seem to agree: The development of technology for putting ideas on paper provides some insight into how CNCs will continue to develop. The two technologies could be said to have followed parallel courses already. The manual typewriter, for example, equates to a manual machine tool. In both cases, the operator pushed levers that directly corresponded to what he wanted the machine to do. Later, operators of both types of equipment acquired the ability to input commands all at once, and have the machine execute them in sequence later. The typist moved up to a word processor, and the manual machinist moved up to NC.
Today, the difference between these two technologies is that the word processor is now a software-only product that has made the jump completely away from proprietary hardware. The word processor today can run on any number of generic PCs, can have its documents printed on any commonly used printer, and can even interact with a variety of printers and other peripherals sharing a common network. Can we assume from this that someday we will see software-only CNCs, which run on any computer, and control any of a variety of machine tools without the need for costly system integration?
In short, will everything needed to install a CNC one day come in a shrink-wrapped box?
Probably yes. At least, that's what a variety of successful CNC vendors believe. However, one can only guess how soon that day will come. And it may not come for some time.
There is another piece of office equipment that offers a loose parallel to machine tool technology. This is the CAD plotter—the one used to make hard-copy prints of CAD drawings. This device looks a lot like a machining center. It has a tool (the pen) and a toolchanger (to switch to other pens). It interpolates in linear axes to draw complex lines. And it even has material handling, for loading the next sheet of paper.
With a machine tool, there is a difference of degree; the machining center requires more complex control functions than the plotter. However, the machine tool in service today is also different in a fundamental way: It was never designed with the intention that a plug-in PC would be running it.
That may change. The day may come when machine tool builders see their iron as PC peripherals similar to printers or plotters. However, because that day is not here yet, any shop looking at CNCs right now must give consideration to the different ways generic PC hardware is applied right now.
This is the nature of CNC shopping today. Exactly which strengths the control should deliver, and just how much non-proprietary hardware is right for the application, are choices which today's CNC market makes freely available to the consumer.
The vendors mentioned in this article can all provide more information on the CNC technology they offer.
http://www.mmsonline.com/articles/059803.html
This exponential pace of development affects computers everywhere. But on the floor of a machine shop, the impact is particularly striking. Here, rapidly evolving computer numerical controls (CNCs) meet machine tools whose basic structures have changed little since before these controls were introduced. The lopsided rate of change often means that the machine tool remains mechanically sound and serviceable long after its control has been eclipsed by newer models. There is no Moore's Law for the iron. As a result, some shops find themselves saddled with inoperative machines, idled only because the control is obsolete and replacement components can no longer be found. Still more shops use CNC machines whose mechanical structures could be employed much more effectively if only the controls had access to the power and features of more recently developed models. In each of these cases, one option is to scrap the old machine in favor of an entirely new one, with its own new control. However, another option is to retain the mechanical structure, and retrofit a replacement CNC.
Conserving the iron in this way is not always the more economical choice. CNCs are not simply plug-in devices. Any combination of CNC and machine tool is in fact a carefully engineered system, and the work of integrating this system is typically more expensive than the CNC itself. A new, mass-produced machine tool carries almost none of this engineering cost. The OEM spreads the one-time expense for system integration across the entire run of that machine. That option is not available for most retrofit jobs, where the "production run" typically amounts to just one unit.
Because of this integration expense and its effect on overall cost, many shops don't even consider CNC retrofitting. And perhaps rightly so; retrofitting instead of buying new is still cost-effective only for a minority of machine tools. However, retrofitting today may be worth a second look. The economics have changed significantly, even in just the last five years. There is an expanded range of choices among retrofit CNCs, and this has produced an expanded range of machine tools for which retrofitting now makes sense.
CNC
Today, two things can be said of the CNC retrofit market:
1. Machines that were once too old to justify a CNC retrofit now make excellent candidates.
2. Machines that were once too new to justify a CNC retrofit also make excellent candidates.
In the case of the older machines, today's controls are more forgiving of ballscrew error, backlash, way friction and other symptoms of mechanical wear. By compensating electronically for these errors, the right CNC alone may be enough to return a worn machine to like-new precision. Thus, the retrofit may not have to include costs for replacement bearings, ballscrews, or gearing, or for scraping the ways or other mechanical service.
In the case of the newer machines, recent improvements in control technology can make a more recent or more specialized CNC far more productive for the machine than its standard control unit, even when that older control is still functioning well. The retrofit CNC may offer important capabilities the standard one does not, including:
* High-feed rate, high-accuracy machining, particularly during contour milling. This can be the result of features including look-ahead, faster servo updates, and curve interpolation. It can also be the result of expanded program storage capacity or faster data transmission across a network.
* The ability to run third-party PC software directly on the control, for functions like shopfloor programming, or updating machining offsets based on trends in SPC data.
* Data exchange with networked PCs. Fast, two-way data transfer not only enables the CNC to obtain a part program quickly from a remote source, but can also let a remote PC monitor and react to the machine's status.
CNC Retrofit
Most of these benefits are products of increased computing power (a la Moore's Law), which has expanded the choices available to control buyers by allowing CNCs to deliver more sophisticated and specialized functions. However, there is another factor spurring CNC development. Some features, like memory and networking improvements, have grown from the low-cost platform now available thanks to the spread of non-proprietary, commodity PC hardware. And this PC hardware has also produced more choices, as different CNC vendors apply the hardware in different ways.
If you are shopping for a replacement control, should you choose one that is in some way PC-based or PC-interfaced? Today there is a good chance the answer is yes.
But does this mean you should favor the control that includes the most off-the-shelf PC hardware? Not necessarily.
No, the best way to choose a replacement CNC in today's market is to take advantage of the range of choice now available to find the right control for the application. This will mean selecting the one that best delivers the features—including price—which that application demands. However, it will also mean finding the most appropriate mix of proprietary and non-proprietary hardware.
Not "Either/Or"
There are varying degrees to which a control can employ widely available hardware. Thus "proprietary" and "non-proprietary" are not either/or conditions. They can better be imagined as opposite directions along a common axis.
At the extreme "proprietary" end of this axis would be the CNC which was essentially the only type available ten years ago. This control has hardware built or specified entirely by the manufacturer, and at best offers only a slow serial interface for (one-way) data exchange.
PC-based Control
PC-based Control
PC-based Control
PC-based Control
A PC front end can bring networking, memory, and third-party software benefits to a control system that still offers the advantages of single-source hardware. Illustration courtesy GE Fanuc.
Today, at or near the opposite end of this axis would be a control like the one offered by Manufacturing Data Systems, Inc. (MDSI; Ann Arbor, Michigan). Designed to permit a low-cost retrofit, or low-cost entry into CNC networking, MDSI's control consists of PC software running entirely on non-proprietary hardware. Its hardware requirements include a touch-screen monitor, and interface cards for encoders, servos, and I/O, all of which can be purchased from any of a variety of vendors. It has no motion control card. Instead, it closes the servo loop via algorithms in the software. For this reason, it requires just a digital-to-analog converter to interface with the servomotors.
Between these two extremes would be a CNC like the one offered by Creative Technology Corporation (Arlington Heights, Illinois). This is a control optimized to serve the needs of shops interested in milling intricate contoured forms at high feed rates. These include makers of molds, dies, and prototype parts. Accordingly, this PC-based control employs one particular vendor's motion control card, chosen for its fast servo cycle time, among other features. While this single-source card technically qualifies as proprietary hardware, the overall control is not as proprietary as the "extreme" proprietary control cited above. The customer does not have to return to the control vendor for replacement parts or upgrades. The maker of the motion control card has licensed the right to produce and market its hardware to a variety of competing manufacturers, and the rest of the control consists of generic PC hardware that is widely available.
This leads to another frequently used CNC term necessary to carry this discussion further. That term is open. (As in, "open architecture.") It is used together with "PC-based" so often that the two may appear identical in meaning. However, while the definitions may overlap, these two terms describe very different ideas.
In fact, different CNC vendors embrace any of at least two definitions for an open control. Some define this as a control using off-the-shelf hardware, which therefore (in theory) can be maintained and upgraded inexpensively, without the vendor's involvement.
Other vendors view an open control as one that can easily share information across a network. This information includes both input, like an NC program, and output, like machine status data.
These two definitions of open don't necessarily go together. A CNC can be open to hardware without being open to a network, and a CNC favoring proprietary hardware can be constructed to interface with a network freely. In the retrofit world, one example of this second case comes from Memex Electronics (Burlington, Ontario, Canada), which offers retrofit boards allowing older, "closed" Fanuc CNCs to connect directly to a PC network.
However, a more general example of a system delivering network openness to a proprietary CNC comes from yet another approach to a control employing PC hardware. This is an approach offered by GE Fanuc (Charlottesville, Virginia) and Siemens (Elk Grove Village, Illinois), among others. These companies place a PC front end on a control system in which all hardware comes from a single source—from pushbuttons through servomotors. This is the PC-enabled control system that most resembles the traditional, proprietary CNC. And for this reason, it may be the right approach for many applications.
Costs And Benefits
The determining factor, according to both GE Fanuc and Siemens, is the productive value of the machine tool.
For example, the purpose of a CNC retrofit may be to give new life to a machine that is non-critical and/or relatively inexpensive. The machine may be one that sits idle because needed hardware for its dated control can no longer be found, or because the control itself limits the machine's capabilities or makes it difficult to use. The machine may also be a low-cost vertical machining center that a different control might make faster or more accurate. In any of these cases, the shop will likely see the productivity gain from a retrofit as "gravy"—extra machining capacity acquired for significantly less than the cost of buying a new machine. If so, then the shop has to minimize the cost of the retrofit to make the upgrade cost-effective. This means finding the most inexpensive control that is feasible, and this may well mean choosing one that maximizes its use of widely available electronics.
But as the value of the machine tool increases, the outlook may change. There is no precise dollar value at which a machine can no longer be said to be "low cost." However, somewhere on an ascending scale of the machine's replacement cost—whether this is $200,000, $300,000, $500,000—there comes a point where the machine is valuable enough, and machine downtime is costly enough, that a compelling case can be made for proprietary hardware. With a single-source control system, the shop has the support of just one vendor behind all of the electronics that keep this costly machine productive.
Siemens marketing manager Peter Herweck adds another consideration when evaluating a largely non-proprietary control versus a largely proprietary one. A common selling point of the former option is its promise to let the buyer upgrade the control without the vendor's involvement, just as one would upgrade an office PC. The more proprietary controls do not promise this same freedom. However, Mr. Herweck cautions potential CNC buyers to weigh how valuable this promise really is. Questions he would have them ask include: "How often will I really want to upgrade this control? Can I truly perform this upgrade more economically in-house? And if so, am I willing to trade the support advantages of a single-source control to realize these savings?"
As for the other selling points of a non-proprietary control, he notes that a more proprietary control can also deliver these. He lists them: "Expanded part program storage; freedom to run third-party software; and data I/O, whether this is networking, zip or floppy drive, or a PCMCIA slot. A single-source control with a PC front end can provide all of these advantages," he says. And while the single-source system adds the support benefits to this, he notes that it also delivers these benefits not through general-purpose hardware, but via hardware that has been engineered around one function—reliably and repeatably controlling a machine tool.
The argument, in other words, is that you get what you pay for. However, today's market offers a corollary to this: If you don't want to pay for the advantages of a proprietary system, you no longer have to. Both of the less-proprietary systems mentioned in this article illustrate this, albeit in different ways. Using MDSI's control, shops have not only "resurrected" machines that were once too low-cost to justify retrofitting, but in some cases have realized performance benefits—including accuracy at higher feed rates—which the original control never permitted. And the specialized focus of the Creative Technology control has allowed die-mold shops to devote the price of a CNC retrofit to maximizing the control features most beneficial to the die-mold milling application. In fact, the control's benefits have proven profitable enough in this application that some die-mold shops have not waited for obsolescence, but instead have retrofitted the control to practically new vertical machining centers.
Upgrades like these illustrate how CNC technology has evolved rapidly in recent years. As to where this evolution might lead, the answer may lie no farther (from me) than my own fingertips.
Look To The Office
I am writing this article on a word processor. By this I mean a generic PC running word processing software. One generation ago, another person doing my job would have used a typewriter. A little later, that same editor might have used one of the early versions of the word processor. This first word processor was not an "open" system, but instead a dedicated machine. Its built-in logic could be upgraded only through a costly hardware replacement.
CNC vendors seem to agree: The development of technology for putting ideas on paper provides some insight into how CNCs will continue to develop. The two technologies could be said to have followed parallel courses already. The manual typewriter, for example, equates to a manual machine tool. In both cases, the operator pushed levers that directly corresponded to what he wanted the machine to do. Later, operators of both types of equipment acquired the ability to input commands all at once, and have the machine execute them in sequence later. The typist moved up to a word processor, and the manual machinist moved up to NC.
Today, the difference between these two technologies is that the word processor is now a software-only product that has made the jump completely away from proprietary hardware. The word processor today can run on any number of generic PCs, can have its documents printed on any commonly used printer, and can even interact with a variety of printers and other peripherals sharing a common network. Can we assume from this that someday we will see software-only CNCs, which run on any computer, and control any of a variety of machine tools without the need for costly system integration?
In short, will everything needed to install a CNC one day come in a shrink-wrapped box?
Probably yes. At least, that's what a variety of successful CNC vendors believe. However, one can only guess how soon that day will come. And it may not come for some time.
There is another piece of office equipment that offers a loose parallel to machine tool technology. This is the CAD plotter—the one used to make hard-copy prints of CAD drawings. This device looks a lot like a machining center. It has a tool (the pen) and a toolchanger (to switch to other pens). It interpolates in linear axes to draw complex lines. And it even has material handling, for loading the next sheet of paper.
With a machine tool, there is a difference of degree; the machining center requires more complex control functions than the plotter. However, the machine tool in service today is also different in a fundamental way: It was never designed with the intention that a plug-in PC would be running it.
That may change. The day may come when machine tool builders see their iron as PC peripherals similar to printers or plotters. However, because that day is not here yet, any shop looking at CNCs right now must give consideration to the different ways generic PC hardware is applied right now.
This is the nature of CNC shopping today. Exactly which strengths the control should deliver, and just how much non-proprietary hardware is right for the application, are choices which today's CNC market makes freely available to the consumer.
The vendors mentioned in this article can all provide more information on the CNC technology they offer.
http://www.mmsonline.com/articles/059803.html
Retrofit CNC adds life
Rather than replace an older, but very useful CNC horizontal machining centre, a vintage car restorer opted to retrofit an up-to-date CNC and so saved on machine tool replacement costs
The opportunity to turn a hobby into a business doesn't arise every day, but this is exactly what happened to Will Fiennes, a lifelong fan of Riley motor cars, 30 years ago he hung up his physicist boots to follow his passion of restoring vintage motor cars. Leaving behind his role with Smiths Industries - where he applied his degree in tribology, electrical engineering and physics - and upon establishing Fiennes Restoration because he 'preferred to get his hands dirty', he focused on the supply of new spare parts for, and the restoration of, pre-war Derby Bentley and Rolls-Royce cars.
This article was originally published on Manufacturingtalk on 12 March 2007 at 8.00am (UK)
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Such is the success of the operation that today he works for customers the world over.
'It was clear then that not many people knew too much about these cars,' said Fiennes, 'And that the supply of appropriate spares was dwindling.
So, having identified that demand, I set about satisfying it.' To give some idea of the scale of the operation, at any one time around 20 cars are at various stages of restoration, and the spares inventory now extends to an amazing 7,000 different line items, all computerised and 'accessible' online (www.fiennes.co.uk) via the company's website.
'The business hasn't changed that much during the past decades,' he reflected, 'Though CNC machines have helped us considerably to achieve consistently accurate and more cost-effective batches of machined parts.' He said: 'In this respect, CNC brings a new dimension to the word 'efficiency' even for a company like this (where a large batch may be just five-off components) though our manual machines do remain very effective for the production of suitable, relatively simple jobs.' He explained that the company havd a very old Britan capstan lathe, which it had bought secondhand with a new CNC lathe, and this wonderfully designed machine continues to reliably and accurately produce bushes and other small parts.
Fiennes said: 'I discovered during the early days of Fiennes Restoration that nothing is impossible; everything can be made if you have the right tools and attitude.
Further reading
'Go/no-go' component inspection made easy
Measurement and control specialist ACI (UK) has made available Metronics' Gage-Chek, a 'go/no-go' gauge for checking even the most complex components
Powerful digital readout system at low cost
Measurement and control specialist ACI (UK) has announced the one-/two-/three-axis Anilam Wizard 411 digital readout (DRO) system, an entry-level DRO with powerful functionality
CNCs, DROs give easy students' programming
A university engineering department didn't want students spending hours lwriting programs, so it sought machine tool control systems that allowed quick and easy programs development
But over the years it has become clear that the nation's craft skills have dwindled rapidly, though we've been lucky in being able to maintain a high skills base, even though we're based in the wilds of Oxfordshire.' This is certainly evident among the company's 23 employees, and particularly in the mechanical restoration, coachwork and spare parts machining activities, where a very high standard of manual dexterity combines perfectly with high-technology equipment, tools and materials to enable the workforce to achieve finished results that the original car manufacturers would envy.
CNC was introduced 18 years ago, following a contract to machine cylinder head castings.
But lead times were extended to 40 hours per head when machining these parts on a DRO-driven vertical milling machine, and then sub-contracting the thread milling content as well as combustion chamber machining.
One option was to invest in CNC machinery.
However, to some extent this required a leap of faith, machining components designed 60 or 70 years ago using modern technology.
'I was sure that the way to shorten such an extensive lead time was to machine as much as possible in-house by CNC; ideally by using a horizontal machining centre where all faces of the castings could be machined in a single set-up,' said Fiennes.
'But a horizontal would have cost us at least six times more than the route we adopted - a CNC Avon turret mill, fitted with Anilam GXM control.
The versatility of the Avon allowed us to machine all faces of the 28in long casting with appropriate fixtures, albeit with a sacrifice of rigidity.' He said: 'This served us well for 15 years, when we found that increasing demand could not be met by the now elderly Avon.
We then invested in a new VMC with full fourth axis, but did not dispose of the Avon.
In fact, the VMC could not do everything that the Avon did, and in particular the end faces of the cylinder head castings continued to be machined on the Avon.
It has to be said that the horizontal option, with a substantially greater investment, would have allowed all the machining to be achieved on the one machine.' However, while the Avon has remained mechanically sound (ballscrews and motors, for example, were fine), the G and M code programming routines via the original GXM control were, he says, obviously suffering from age and were proving tiresome.
But rather than invest in another new vertical mill or machining centre, Will Fiennes decided that an Anilam 3000 Series CNC upgrade from ACI (UK) would be an ideal solution - and at least 70% cheaper than investing in an equivalent new machine.
ACI (UK) simply replaced the control and wiring, and the machine - which suffered a downtime of no more than 48h - 'Has been given a new lease of life', Fiennes said.
With the switch to the three-axis Anilam 3000M CNC, and after suitable onsite training, the ease of use of Anilam's renowned Machinist's Language quickly came to the fore.
Of particular merit, said Fiennes, was the control's wide range of standard cycles such as 'peck' drilling, pocket milling and face milling, as well as its advanced cycles that include ellipse, spiral, helical, tapping, irregular pocket milling and profile milling.
The special cycles such as counterboring are also highlighted as being especially useful.
Illustrating the system's ease of use, he says, is the standard cycle for bolt hole patterns that enables patterns of any configuration to be quickly produced by answering five simple questions.
Likewise, after answering a few questions, the drill cycle takes users through simple drill, peck drill and boring routines.
'In addition to the continuation of the cylinder head work, the revitalised Avon is used for producing a myriad of parts including the machining of small castings and various moulds and tool steel components that utilise the machine/control combination's three-axis capabilities.' Fiennes said: 'I set up Fiennes Restoration with no formal business training, which is just as well, because we continue to this day to break every rule in the business book, particularly in terms of best practice work-in-progress and stock levels.' He concluded: 'But I'd like to think that I've learned a thing or two over the years, and the financial sense of adopting the ACI (UK) rebuild is one example.
It's a business I wouldn't change for the world - and when I do find time to retire, I've still got a Riley waiting at home for me to restore.'
Retrofit CNC raises long bed miller productivity
Control reliability and ease-of-use were the key factors in a subcontrac tor’s decision to change to GE Fanuc for the CNC and drives of a long-bed, travelling gantry Cincinnati machining centre. Gardner Aerospace-Hull, one of the seven businesses that make up Gardner Group in the UK, has called on the services of Halifax Numerical Controls (HNC) to retro-fit a 40m long travelling gantry Cincinnati Milacron machining centre with a GE Fanuc controller to manufacture parts for Airbus.
Both Gardner and HNC agreed that reliability and ease-of-use were key factors in the decision to change to GE Fanuc for the CNC and drives.
The Cincinnati Milacron machine has a 40m long x 4m wide horizontal bed machining area shared by two gantries each carrying 3 identical heads.
Each gantry can access up to 31m on the X-axis.
The 3 heads per gantry operate with identical motions across the 2m Y-axis, have 500mm travel in the Z-axis, and +/-20 deg movements on their A and B axes.
There are two synchronous motors for motion along the X-axis, one on either side to ensure positioning accuracy.
Mike Diskin managing director of HNC, explained the decision to fit GE Fanuc controls and drives.
‘The machine was imported from the US, and when unpacked it was obvious that one gantry controller needed replacement.
Gardner Aerospace came to us as we have been carrying out machine tool servicing for them for many years.
We enquired about replacing the numerical control with a similar product from the original manufacturer, but it was now an obsolete model which could be replaced only at a high price.
When we can, we recommend GE Fanuc products for retrofitting as we find them the most straightforward to install and commission, and also very reliable once in operation.
We were able to quote a good package price to our customer based on a Series 16i CNC with GE Fanuc 40Nm Alpha (HV)i Series servo motors on all axes.
The 16i also enables development of other facilities as the demand arises.’ Paul Smith, Engineering/Manufacturing manager at Gardner Aerospace, explained: ‘The Series 16i is fitted with a 64 Bit RISC processor, an option which is well suited to the machining of aluminium.’ He said: ‘It enhances our productivity as it processes the part programs at higher speeds enabling the cutting tools to traverse at higher rates, while at the same time maintaining the high accuracy of the machined profiles of the highly complex parts.’ Smith explained that the compact (HV)i version Alpha Series servo motors were chosen to provide the high speed and accuracy required for machining aluminium, which now makes up 99% of Gardner Aerospace’s work.
He said that productivity is further enhanced by the absolute encoders on the servo motors which ensure the machine can go straight into production on start up, without the need to reference the 40m long X-axis.
Smith continued, ‘Airbus has been a long-term customer for whom we manufacture precision engineered airframe parts.
We have been producing, for example, wing spars and wing skins around 16m long, cut from single pieces of aluminium.
With this additional machine we shall be able to manufacture parts for the new, largest planes, including the A380, which are now starting to fill the Airbus order books.
Our productivity will be high as we shall be able to produce three parts simultaneously, side by side, in single hit machining.’ The decision to go for GE Fanuc was endorsed unequivocally by Smith: ‘A large majority of our machines are fitted with GE Fanuc controllers.
I cannot remember a problem with GE Fanuc technology in 20 years of working within this company, and our operators find the CNCs easy to set up and use.
For us it is an ideal solution.
HNC is a reliable organisation and this will be the second Series 16i CNC they have retrofitted for us in the past 18 months.’
http://www.manufacturingtalk.com
Both Gardner and HNC agreed that reliability and ease-of-use were key factors in the decision to change to GE Fanuc for the CNC and drives.
The Cincinnati Milacron machine has a 40m long x 4m wide horizontal bed machining area shared by two gantries each carrying 3 identical heads.
Each gantry can access up to 31m on the X-axis.
The 3 heads per gantry operate with identical motions across the 2m Y-axis, have 500mm travel in the Z-axis, and +/-20 deg movements on their A and B axes.
There are two synchronous motors for motion along the X-axis, one on either side to ensure positioning accuracy.
Mike Diskin managing director of HNC, explained the decision to fit GE Fanuc controls and drives.
‘The machine was imported from the US, and when unpacked it was obvious that one gantry controller needed replacement.
Gardner Aerospace came to us as we have been carrying out machine tool servicing for them for many years.
We enquired about replacing the numerical control with a similar product from the original manufacturer, but it was now an obsolete model which could be replaced only at a high price.
When we can, we recommend GE Fanuc products for retrofitting as we find them the most straightforward to install and commission, and also very reliable once in operation.
We were able to quote a good package price to our customer based on a Series 16i CNC with GE Fanuc 40Nm Alpha (HV)i Series servo motors on all axes.
The 16i also enables development of other facilities as the demand arises.’ Paul Smith, Engineering/Manufacturing manager at Gardner Aerospace, explained: ‘The Series 16i is fitted with a 64 Bit RISC processor, an option which is well suited to the machining of aluminium.’ He said: ‘It enhances our productivity as it processes the part programs at higher speeds enabling the cutting tools to traverse at higher rates, while at the same time maintaining the high accuracy of the machined profiles of the highly complex parts.’ Smith explained that the compact (HV)i version Alpha Series servo motors were chosen to provide the high speed and accuracy required for machining aluminium, which now makes up 99% of Gardner Aerospace’s work.
He said that productivity is further enhanced by the absolute encoders on the servo motors which ensure the machine can go straight into production on start up, without the need to reference the 40m long X-axis.
Smith continued, ‘Airbus has been a long-term customer for whom we manufacture precision engineered airframe parts.
We have been producing, for example, wing spars and wing skins around 16m long, cut from single pieces of aluminium.
With this additional machine we shall be able to manufacture parts for the new, largest planes, including the A380, which are now starting to fill the Airbus order books.
Our productivity will be high as we shall be able to produce three parts simultaneously, side by side, in single hit machining.’ The decision to go for GE Fanuc was endorsed unequivocally by Smith: ‘A large majority of our machines are fitted with GE Fanuc controllers.
I cannot remember a problem with GE Fanuc technology in 20 years of working within this company, and our operators find the CNCs easy to set up and use.
For us it is an ideal solution.
HNC is a reliable organisation and this will be the second Series 16i CNC they have retrofitted for us in the past 18 months.’
http://www.manufacturingtalk.com
Retrofit CNC adds life to useful machining centre
Rather than replace an older, but very useful CNC horizontal machining centre, a vintage car restorer opted to retrofit an up-to-date CNC and so saved on machine tool replacement costsThe opportunity to turn a hobby into a business doesn't arise every day, but this is exactly what happened to Will Fiennes, a lifelong fan of Riley motor cars, 30 years ago he hung up his physicist boots to follow his passion of restoring vintage motor cars. Leaving behind his role with Smiths Industries - where he applied his degree in tribology, electrical engineering and physics - and upon establishing Fiennes Restoration because he 'preferred to get his hands dirty', he focused on the supply of new spare parts for, and the restoration of, pre-war Derby Bentley and Rolls-Royce cars.
Such is the success of the operation that today he works for customers the world over.
'It was clear then that not many people knew too much about these cars,' said Fiennes, 'And that the supply of appropriate spares was dwindling.
So, having identified that demand, I set about satisfying it.' To give some idea of the scale of the operation, at any one time around 20 cars are at various stages of restoration, and the spares inventory now extends to an amazing 7,000 different line items, all computerised and 'accessible' online (www.fiennes.co.uk) via the company's website.
'The business hasn't changed that much during the past decades,' he reflected, 'Though CNC machines have helped us considerably to achieve consistently accurate and more cost-effective batches of machined parts.' He said: 'In this respect, CNC brings a new dimension to the word 'efficiency' even for a company like this (where a large batch may be just five-off components) though our manual machines do remain very effective for the production of suitable, relatively simple jobs.' He explained that the company havd a very old Britan capstan lathe, which it had bought secondhand with a new CNC lathe, and this wonderfully designed machine continues to reliably and accurately produce bushes and other small parts.
Fiennes said: 'I discovered during the early days of Fiennes Restoration that nothing is impossible; everything can be made if you have the right tools and attitude.
But over the years it has become clear that the nation's craft skills have dwindled rapidly, though we've been lucky in being able to maintain a high skills base, even though we're based in the wilds of Oxfordshire.' This is certainly evident among the company's 23 employees, and particularly in the mechanical restoration, coachwork and spare parts machining activities, where a very high standard of manual dexterity combines perfectly with high-technology equipment, tools and materials to enable the workforce to achieve finished results that the original car manufacturers would envy.
CNC was introduced 18 years ago, following a contract to machine cylinder head castings.
But lead times were extended to 40 hours per head when machining these parts on a DRO-driven vertical milling machine, and then sub-contracting the thread milling content as well as combustion chamber machining.
One option was to invest in CNC machinery.
However, to some extent this required a leap of faith, machining components designed 60 or 70 years ago using modern technology.
'I was sure that the way to shorten such an extensive lead time was to machine as much as possible in-house by CNC; ideally by using a horizontal machining centre where all faces of the castings could be machined in a single set-up,' said Fiennes.
'But a horizontal would have cost us at least six times more than the route we adopted - a CNC Avon turret mill, fitted with Anilam GXM control.
The versatility of the Avon allowed us to machine all faces of the 28in long casting with appropriate fixtures, albeit with a sacrifice of rigidity.' He said: 'This served us well for 15 years, when we found that increasing demand could not be met by the now elderly Avon.
We then invested in a new VMC with full fourth axis, but did not dispose of the Avon.
In fact, the VMC could not do everything that the Avon did, and in particular the end faces of the cylinder head castings continued to be machined on the Avon.
It has to be said that the horizontal option, with a substantially greater investment, would have allowed all the machining to be achieved on the one machine.' However, while the Avon has remained mechanically sound (ballscrews and motors, for example, were fine), the G and M code programming routines via the original GXM control were, he says, obviously suffering from age and were proving tiresome.
But rather than invest in another new vertical mill or machining centre, Will Fiennes decided that an Anilam 3000 Series CNC upgrade from ACI (UK) would be an ideal solution - and at least 70% cheaper than investing in an equivalent new machine.
ACI (UK) simply replaced the control and wiring, and the machine - which suffered a downtime of no more than 48h - 'Has been given a new lease of life', Fiennes said.
With the switch to the three-axis Anilam 3000M CNC, and after suitable onsite training, the ease of use of Anilam's renowned Machinist's Language quickly came to the fore.
Of particular merit, said Fiennes, was the control's wide range of standard cycles such as 'peck' drilling, pocket milling and face milling, as well as its advanced cycles that include ellipse, spiral, helical, tapping, irregular pocket milling and profile milling.
The special cycles such as counterboring are also highlighted as being especially useful.
Illustrating the system's ease of use, he says, is the standard cycle for bolt hole patterns that enables patterns of any configuration to be quickly produced by answering five simple questions.
Likewise, after answering a few questions, the drill cycle takes users through simple drill, peck drill and boring routines.
'In addition to the continuation of the cylinder head work, the revitalised Avon is used for producing a myriad of parts including the machining of small castings and various moulds and tool steel components that utilise the machine/control combination's three-axis capabilities.' Fiennes said: 'I set up Fiennes Restoration with no formal business training, which is just as well, because we continue to this day to break every rule in the business book, particularly in terms of best practice work-in-progress and stock levels.' He concluded: 'But I'd like to think that I've learned a thing or two over the years, and the financial sense of adopting the ACI (UK) rebuild is one example.
It's a business I wouldn't change for the world - and when I do find time to retire, I've still got a Riley waiting at home for me to restore.'
http://www.manufacturingtalk.com/news/aie/aie201.html
Such is the success of the operation that today he works for customers the world over.
'It was clear then that not many people knew too much about these cars,' said Fiennes, 'And that the supply of appropriate spares was dwindling.
So, having identified that demand, I set about satisfying it.' To give some idea of the scale of the operation, at any one time around 20 cars are at various stages of restoration, and the spares inventory now extends to an amazing 7,000 different line items, all computerised and 'accessible' online (www.fiennes.co.uk) via the company's website.
'The business hasn't changed that much during the past decades,' he reflected, 'Though CNC machines have helped us considerably to achieve consistently accurate and more cost-effective batches of machined parts.' He said: 'In this respect, CNC brings a new dimension to the word 'efficiency' even for a company like this (where a large batch may be just five-off components) though our manual machines do remain very effective for the production of suitable, relatively simple jobs.' He explained that the company havd a very old Britan capstan lathe, which it had bought secondhand with a new CNC lathe, and this wonderfully designed machine continues to reliably and accurately produce bushes and other small parts.
Fiennes said: 'I discovered during the early days of Fiennes Restoration that nothing is impossible; everything can be made if you have the right tools and attitude.
But over the years it has become clear that the nation's craft skills have dwindled rapidly, though we've been lucky in being able to maintain a high skills base, even though we're based in the wilds of Oxfordshire.' This is certainly evident among the company's 23 employees, and particularly in the mechanical restoration, coachwork and spare parts machining activities, where a very high standard of manual dexterity combines perfectly with high-technology equipment, tools and materials to enable the workforce to achieve finished results that the original car manufacturers would envy.
CNC was introduced 18 years ago, following a contract to machine cylinder head castings.
But lead times were extended to 40 hours per head when machining these parts on a DRO-driven vertical milling machine, and then sub-contracting the thread milling content as well as combustion chamber machining.
One option was to invest in CNC machinery.
However, to some extent this required a leap of faith, machining components designed 60 or 70 years ago using modern technology.
'I was sure that the way to shorten such an extensive lead time was to machine as much as possible in-house by CNC; ideally by using a horizontal machining centre where all faces of the castings could be machined in a single set-up,' said Fiennes.
'But a horizontal would have cost us at least six times more than the route we adopted - a CNC Avon turret mill, fitted with Anilam GXM control.
The versatility of the Avon allowed us to machine all faces of the 28in long casting with appropriate fixtures, albeit with a sacrifice of rigidity.' He said: 'This served us well for 15 years, when we found that increasing demand could not be met by the now elderly Avon.
We then invested in a new VMC with full fourth axis, but did not dispose of the Avon.
In fact, the VMC could not do everything that the Avon did, and in particular the end faces of the cylinder head castings continued to be machined on the Avon.
It has to be said that the horizontal option, with a substantially greater investment, would have allowed all the machining to be achieved on the one machine.' However, while the Avon has remained mechanically sound (ballscrews and motors, for example, were fine), the G and M code programming routines via the original GXM control were, he says, obviously suffering from age and were proving tiresome.
But rather than invest in another new vertical mill or machining centre, Will Fiennes decided that an Anilam 3000 Series CNC upgrade from ACI (UK) would be an ideal solution - and at least 70% cheaper than investing in an equivalent new machine.
ACI (UK) simply replaced the control and wiring, and the machine - which suffered a downtime of no more than 48h - 'Has been given a new lease of life', Fiennes said.
With the switch to the three-axis Anilam 3000M CNC, and after suitable onsite training, the ease of use of Anilam's renowned Machinist's Language quickly came to the fore.
Of particular merit, said Fiennes, was the control's wide range of standard cycles such as 'peck' drilling, pocket milling and face milling, as well as its advanced cycles that include ellipse, spiral, helical, tapping, irregular pocket milling and profile milling.
The special cycles such as counterboring are also highlighted as being especially useful.
Illustrating the system's ease of use, he says, is the standard cycle for bolt hole patterns that enables patterns of any configuration to be quickly produced by answering five simple questions.
Likewise, after answering a few questions, the drill cycle takes users through simple drill, peck drill and boring routines.
'In addition to the continuation of the cylinder head work, the revitalised Avon is used for producing a myriad of parts including the machining of small castings and various moulds and tool steel components that utilise the machine/control combination's three-axis capabilities.' Fiennes said: 'I set up Fiennes Restoration with no formal business training, which is just as well, because we continue to this day to break every rule in the business book, particularly in terms of best practice work-in-progress and stock levels.' He concluded: 'But I'd like to think that I've learned a thing or two over the years, and the financial sense of adopting the ACI (UK) rebuild is one example.
It's a business I wouldn't change for the world - and when I do find time to retire, I've still got a Riley waiting at home for me to restore.'
http://www.manufacturingtalk.com/news/aie/aie201.html
Adding a high-speed electric-spindle system to an existing CNC vertical machining center can improve the machine's productivity by providing quick, in
Adding a high-speed electric-spindle system to an existing CNC vertical machining center can improve the machine's productivity by providing quick, infinitely variable speed selection and higher rpm capabilities. Integrating the auxiliary spindle permanently onto the machine allows a company to meet the constantly changing demands of machining fine details and still retain the main spindle's capabilities for larger cutters.
In a typical application, one company recently purchased a five-axis Fadal VMC 4020 vertical machining center and modified it so it could also be used for machining fluidic circuit prototypes. Modifications include a Precise SC 102-O high speed electric spindle system (Precise Corp., Racine, Wisconsin), a special mounting plate that allows the spindle to remain in place while the main spindle is in use, some tool changer and programming adaptations, and cable carriers to keep all fluid and electrical lines neat and manageable.
The high rpm capability makes it possible to use carbide end mills from as small as 0.009" diameter up to about 1/4-inch. To make the high spindle rpm needed for small diameter cutters readily available, the auxiliary Precise spindle is mounted permanently on the side of the machine's column. Offset approximately ten inches, the spindle's fixed location enables it to be programmed into operations with little or no special accommodation. The machine's main spindle remains intact to provide the higher power and lower speed range needed to use larger diameter cutters.
With the auxiliary spindle, tools are set up in their own quickchange toolholders. This makes it possible to preset all of the tools and quickly change from tool to tool as needed, roughing with a larger diameter end mill for part of the program and finishing with smaller diameter end mills.
The machine can be programmed so switching from the main spindle to the high speed spindle can be done quickly, without interruption. When the operator specifies a speed above the main spindle's 10,000 rpm limit, the custom postprocessor recognizes the condition and applies the fixture offset, negates the main spindle, turns on the auxiliary spindle, turns it off when the cycle is through and returns to the main spindle.
The Precise spindle is equipped for automatic tool changing but the toolholder release can also be operated manually. A conveniently located pushbutton that releases the toolholder is tied to a zero-speed sensor so the tool will not be released until the operator is ready. Pre-set tooling allows the cutters to be changed quickly.
http://www.mmsonline.com/articles/0995bp3.html
In a typical application, one company recently purchased a five-axis Fadal VMC 4020 vertical machining center and modified it so it could also be used for machining fluidic circuit prototypes. Modifications include a Precise SC 102-O high speed electric spindle system (Precise Corp., Racine, Wisconsin), a special mounting plate that allows the spindle to remain in place while the main spindle is in use, some tool changer and programming adaptations, and cable carriers to keep all fluid and electrical lines neat and manageable.
The high rpm capability makes it possible to use carbide end mills from as small as 0.009" diameter up to about 1/4-inch. To make the high spindle rpm needed for small diameter cutters readily available, the auxiliary Precise spindle is mounted permanently on the side of the machine's column. Offset approximately ten inches, the spindle's fixed location enables it to be programmed into operations with little or no special accommodation. The machine's main spindle remains intact to provide the higher power and lower speed range needed to use larger diameter cutters.
With the auxiliary spindle, tools are set up in their own quickchange toolholders. This makes it possible to preset all of the tools and quickly change from tool to tool as needed, roughing with a larger diameter end mill for part of the program and finishing with smaller diameter end mills.
The machine can be programmed so switching from the main spindle to the high speed spindle can be done quickly, without interruption. When the operator specifies a speed above the main spindle's 10,000 rpm limit, the custom postprocessor recognizes the condition and applies the fixture offset, negates the main spindle, turns on the auxiliary spindle, turns it off when the cycle is through and returns to the main spindle.
The Precise spindle is equipped for automatic tool changing but the toolholder release can also be operated manually. A conveniently located pushbutton that releases the toolholder is tied to a zero-speed sensor so the tool will not be released until the operator is ready. Pre-set tooling allows the cutters to be changed quickly.
http://www.mmsonline.com/articles/0995bp3.html
Retrofitting CNC Machining Center With Auxiliary High RPM Spindle Adds Greater Productivity And Flexibility
Adding a high-speed electric-spindle system to an existing CNC vertical machining center can improve the machine's productivity by providing quick, infinitely variable speed selection and higher rpm capabilities. Integrating the auxiliary spindle permanently onto the machine allows a company to meet the constantly changing demands of machining fine details and still retain the main spindle's capabilities for larger cutters.
In a typical application, one company recently purchased a five-axis Fadal VMC 4020 vertical machining center and modified it so it could also be used for machining fluidic circuit prototypes. Modifications include a Precise SC 102-O high speed electric spindle system (Precise Corp., Racine, Wisconsin), a special mounting plate that allows the spindle to remain in place while the main spindle is in use, some tool changer and programming adaptations, and cable carriers to keep all fluid and electrical lines neat and manageable.
The high rpm capability makes it possible to use carbide end mills from as small as 0.009" diameter up to about 1/4-inch. To make the high spindle rpm needed for small diameter cutters readily available, the auxiliary Precise spindle is mounted permanently on the side of the machine's column. Offset approximately ten inches, the spindle's fixed location enables it to be programmed into operations with little or no special accommodation. The machine's main spindle remains intact to provide the higher power and lower speed range needed to use larger diameter cutters.
With the auxiliary spindle, tools are set up in their own quickchange toolholders. This makes it possible to preset all of the tools and quickly change from tool to tool as needed, roughing with a larger diameter end mill for part of the program and finishing with smaller diameter end mills.
The machine can be programmed so switching from the main spindle to the high speed spindle can be done quickly, without interruption. When the operator specifies a speed above the main spindle's 10,000 rpm limit, the custom postprocessor recognizes the condition and applies the fixture offset, negates the main spindle, turns on the auxiliary spindle, turns it off when the cycle is through and returns to the main spindle.
The Precise spindle is equipped for automatic tool changing but the toolholder release can also be operated manually. A conveniently located pushbutton that releases the toolholder is tied to a zero-speed sensor so the tool will not be released until the operator is ready. Pre-set tooling allows the cutters to be changed quickly.
http://www.mmsonline.com/articles/0995bp3.html
In a typical application, one company recently purchased a five-axis Fadal VMC 4020 vertical machining center and modified it so it could also be used for machining fluidic circuit prototypes. Modifications include a Precise SC 102-O high speed electric spindle system (Precise Corp., Racine, Wisconsin), a special mounting plate that allows the spindle to remain in place while the main spindle is in use, some tool changer and programming adaptations, and cable carriers to keep all fluid and electrical lines neat and manageable.
The high rpm capability makes it possible to use carbide end mills from as small as 0.009" diameter up to about 1/4-inch. To make the high spindle rpm needed for small diameter cutters readily available, the auxiliary Precise spindle is mounted permanently on the side of the machine's column. Offset approximately ten inches, the spindle's fixed location enables it to be programmed into operations with little or no special accommodation. The machine's main spindle remains intact to provide the higher power and lower speed range needed to use larger diameter cutters.
With the auxiliary spindle, tools are set up in their own quickchange toolholders. This makes it possible to preset all of the tools and quickly change from tool to tool as needed, roughing with a larger diameter end mill for part of the program and finishing with smaller diameter end mills.
The machine can be programmed so switching from the main spindle to the high speed spindle can be done quickly, without interruption. When the operator specifies a speed above the main spindle's 10,000 rpm limit, the custom postprocessor recognizes the condition and applies the fixture offset, negates the main spindle, turns on the auxiliary spindle, turns it off when the cycle is through and returns to the main spindle.
The Precise spindle is equipped for automatic tool changing but the toolholder release can also be operated manually. A conveniently located pushbutton that releases the toolholder is tied to a zero-speed sensor so the tool will not be released until the operator is ready. Pre-set tooling allows the cutters to be changed quickly.
http://www.mmsonline.com/articles/0995bp3.html
CNC Retrofit Improves Accuracy And Productivity For Aerospace Components
Stellex Monitor Aerospace Inc. (Amityville, New York) has completed a total CNC retrofit on the fifth of its ten Cincinnati Milacron gantry-style milling machines, which are used in the production of titanium and aluminum aerospace components. The turnkey retrofits were provided by the Siemens Machine Tool Business (Elk Grove Village, Illinois).
Originally equipped with Acramatic “Big Blue” controls, these machines now have Siemens digital servomotors and drives, Sinumerik 840D CNCs running on a Windows XP platform with 3D five-axis cutter compensation and full five-axis real-time kinematical transformation. According to Stellex Vice President Gary Kahrau, the results have already been documented to include reduced setup time, improved surface finish, reduced secondary finishing operations and significant improvements in overall productivity.
The company operates a 250,000 square-foot modern facility. There, it produces struts, spars, landing gear, bulkheads, crown beam assemblies and other medium to large parts from titanium, aluminum and stainless steels for commercial and military aircraft and aerospace vehicles, including space shuttles.
Mr. Kahrau elaborates on some of the 840D features that are benefiting the company. “The open architecture of the control allows us to create our own screens and integrate with our ERP system,” he says. “We store all of our own data on a proprietary ERP system. The data files are dispatched to the CNC, where our custom Shop Workstation program resides. It handles the handshake of the data files with the control. This program is fully integrated with the control’s tool management system as well.”
With the real-time five-axis kinematical transformation called Traori, the 840D control can directly accept the part’s workpiece definition data.
“With the extreme metal removal rates, deep pockets and long contours
typically encountered in aerospace production, this feature of the CNC has demonstrable upsides every day for Stellex,” says Mr. Kahrau.
He further expands upon the open HMI of the CNCs being retrofitted on the Stellex machines. “A cutter diameter compensation and customizable tool management system onboard the 840D give operators quick and accurate information in real time, plus it has the capability to accept additional features as the application demands,” he explains.
Siemens also provided Stellex with an advanced dynamic machine engineering analysis called Mechatronics. First, it collects critical real-time machine performance data, and then it establishes optimized parameterization of the CNC and servodrives. Finally, the analysis verifies optimized performance of the machine. Mr. Kahrau cites the servo analysis, ball bar tests, acceleration/deceleration tests, bi-direction compensation work-up and other protocols as being key to the end results. “Our machinery accuracy is better now than when the machines were new, our five-axis gantry has never performed so well and the rotary axis error was literally cut in half.”
http://www.mmsonline.com/articles/1104bp2.html
Originally equipped with Acramatic “Big Blue” controls, these machines now have Siemens digital servomotors and drives, Sinumerik 840D CNCs running on a Windows XP platform with 3D five-axis cutter compensation and full five-axis real-time kinematical transformation. According to Stellex Vice President Gary Kahrau, the results have already been documented to include reduced setup time, improved surface finish, reduced secondary finishing operations and significant improvements in overall productivity.
 |
| Retrofit operations are performed by Siemens personnel, who also assisted Stellex Monitor Aerospace Inc. with customized software development. |
Mr. Kahrau elaborates on some of the 840D features that are benefiting the company. “The open architecture of the control allows us to create our own screens and integrate with our ERP system,” he says. “We store all of our own data on a proprietary ERP system. The data files are dispatched to the CNC, where our custom Shop Workstation program resides. It handles the handshake of the data files with the control. This program is fully integrated with the control’s tool management system as well.”
With the real-time five-axis kinematical transformation called Traori, the 840D control can directly accept the part’s workpiece definition data.
“With the extreme metal removal rates, deep pockets and long contours
 |
He further expands upon the open HMI of the CNCs being retrofitted on the Stellex machines. “A cutter diameter compensation and customizable tool management system onboard the 840D give operators quick and accurate information in real time, plus it has the capability to accept additional features as the application demands,” he explains.
Siemens also provided Stellex with an advanced dynamic machine engineering analysis called Mechatronics. First, it collects critical real-time machine performance data, and then it establishes optimized parameterization of the CNC and servodrives. Finally, the analysis verifies optimized performance of the machine. Mr. Kahrau cites the servo analysis, ball bar tests, acceleration/deceleration tests, bi-direction compensation work-up and other protocols as being key to the end results. “Our machinery accuracy is better now than when the machines were new, our five-axis gantry has never performed so well and the rotary axis error was literally cut in half.”
http://www.mmsonline.com/articles/1104bp2.html
Machine tools work better with good maintenance
There are still machine tol users who expect machine tools to perform as per specification without the user doing more than applying lubrication - here is how to choose the best maintenance package
It is very important, when using a modern CNC machine tool, to select the right machine and maintenance package. Cincinnati Machine's service division, Maintenance Technologies, delivers structured maintenance programmes that reduce machine tool downtime. Good maintenance also maintains or improves part quality, reduces part costs, prolongs machine tool life and reduces overall maintenance costs.
Maintenance Technologies can improve maintenance and productivity.
The service is part of Cincinnati Machine's MAG industrial automation Systems group.
This group has extensive process knowledge and a wide industrial experience base that serves Cincinnati Machine and all other members of the MAG group of companies.
In comparison with competing maintenance services in the market, Maintenance Technologies philosophy is to provide comprehensive long-term support to maximise Cincinnati Machine equipment availability and productivity.
It also aims to maintaining the lowest cost of ownership for the user throughout the machine tool's life cycle.
Commenting upon Maintenance Technologies, Ian Curlett, sales manager, said: 'We can provide a complete lifecycle support package of to protect a customer's machine tool investment.
This portfolio of products and services is extensive and significantly different from most machine tool suppliers.' Maintenance Technologies works in all three phases of the machine life cycle as described below.
* The first phase - 'machine build, design and installation': it is here that Cincinnati Machine can guarantee a smooth integration of the machine into any workshop.
The package provides interactive technical support, machine certification, machine monitoring, spare parts packages, technical training and application services.
* The second phase - following machine integration, Cincinnati Machine and Maintenance Technologies support the machine operation by offering service parts, machine repair service, continuous oil monitoring and health checks, on-site maintenance contracts and predictive/preventive maintenance contracts.
* The third phase - when the Cincinnati machining or turning centre has served the end user for some time, the company can supply the end user with machine control and drive upgrades.
It will also perform engineering, rebuild, retrofit, re-manufacture repair and exchange services as well as installation, relocation and rigging services as well as the supply of pre-owned equipment.
'We can provide our own team of resident technicians and parts to look after the customers machine tools.
An example of this has been seen at an aerospace company that wanted to increase the productivity of its machine tool assets on a manufacturing site.
We introduced a regime of regular preventative maintenance to ensure the machinery was available for production.
After one year this aerospace customer has realised 3,000 hours of additional machining capacity as a direct result of our involvement and this is improving further in the second year of the contract,' said Curlett.
Demonstrating remarkable reliability and machine build quality, Cincinnati Machine has a considerable amount of longstanding machine tools in the marketplace and for customers with concerns over longevity of these machines; Maintenance Technologies has an extensive archive of machine drawings and manuals to support all products.
An example was recently noted when a diesel engine manufacturer with well serviced but ageing machines had to change its production requirements.
This required two machines with an increased X-axis travel.
As Maintenance Technologies had access to the intellectual property rights for the discontinued machines, it was able to supply an engineered solution and manufacture the two machines to meet the customer needs.
Looking to the future of machine tool maintenance Curlett concluded: 'Provision of machine tool maintenance is moving beyond just reactive services and many customers are asking Maintenance Technologies to work with them on productivity improvements in their manufacturing process'.
'In response to this we have developed a product called Freedom E Log to monitor any machine tool and display the data gathered to develop improvements in OEE (Overall Equipment Effectiveness).
We are pleased to talk to any machine tool user who is interested in using Freedom E Log to increase machining capacity'.
* About Cincinnati Machine - Cincinnati Machine Limited designs, builds and sources high-precision machine tools for the global aerospace, automotive, mould and die, medical and general machining markets.
The company offers technology-driven solutions that include 3-, 4- and 5-axis CNC horizontal and vertical machining centres; and vertical, horizontal and multi-axis turning centres.
Cincinnati Machine in Birmingham, UK is a division focused on the design, development, sales and marketing of the Cincinnati range of machine tools.
Cincinnati Machine is a division within MAG Industrial Automation Systems, headquartered in Michigan, USA.
Other divisions within MAG IAS include Cincinnati Technologies, serving the OEM and Tier 1 aerospace market; Powertrain Technologies, serving the global automotive market with customised high-production solutions; and Maintenance Technologies, responsible for the global after-sales and service parts market for all MAG IAS customers.
http://www.manufacturingtalk.com/news/cci/cci163.html
It is very important, when using a modern CNC machine tool, to select the right machine and maintenance package. Cincinnati Machine's service division, Maintenance Technologies, delivers structured maintenance programmes that reduce machine tool downtime. Good maintenance also maintains or improves part quality, reduces part costs, prolongs machine tool life and reduces overall maintenance costs.
Maintenance Technologies can improve maintenance and productivity.
The service is part of Cincinnati Machine's MAG industrial automation Systems group.
This group has extensive process knowledge and a wide industrial experience base that serves Cincinnati Machine and all other members of the MAG group of companies.
In comparison with competing maintenance services in the market, Maintenance Technologies philosophy is to provide comprehensive long-term support to maximise Cincinnati Machine equipment availability and productivity.
It also aims to maintaining the lowest cost of ownership for the user throughout the machine tool's life cycle.
Commenting upon Maintenance Technologies, Ian Curlett, sales manager, said: 'We can provide a complete lifecycle support package of to protect a customer's machine tool investment.
This portfolio of products and services is extensive and significantly different from most machine tool suppliers.' Maintenance Technologies works in all three phases of the machine life cycle as described below.
* The first phase - 'machine build, design and installation': it is here that Cincinnati Machine can guarantee a smooth integration of the machine into any workshop.
The package provides interactive technical support, machine certification, machine monitoring, spare parts packages, technical training and application services.
* The second phase - following machine integration, Cincinnati Machine and Maintenance Technologies support the machine operation by offering service parts, machine repair service, continuous oil monitoring and health checks, on-site maintenance contracts and predictive/preventive maintenance contracts.
* The third phase - when the Cincinnati machining or turning centre has served the end user for some time, the company can supply the end user with machine control and drive upgrades.
It will also perform engineering, rebuild, retrofit, re-manufacture repair and exchange services as well as installation, relocation and rigging services as well as the supply of pre-owned equipment.
'We can provide our own team of resident technicians and parts to look after the customers machine tools.
An example of this has been seen at an aerospace company that wanted to increase the productivity of its machine tool assets on a manufacturing site.
We introduced a regime of regular preventative maintenance to ensure the machinery was available for production.
After one year this aerospace customer has realised 3,000 hours of additional machining capacity as a direct result of our involvement and this is improving further in the second year of the contract,' said Curlett.
Demonstrating remarkable reliability and machine build quality, Cincinnati Machine has a considerable amount of longstanding machine tools in the marketplace and for customers with concerns over longevity of these machines; Maintenance Technologies has an extensive archive of machine drawings and manuals to support all products.
An example was recently noted when a diesel engine manufacturer with well serviced but ageing machines had to change its production requirements.
This required two machines with an increased X-axis travel.
As Maintenance Technologies had access to the intellectual property rights for the discontinued machines, it was able to supply an engineered solution and manufacture the two machines to meet the customer needs.
Looking to the future of machine tool maintenance Curlett concluded: 'Provision of machine tool maintenance is moving beyond just reactive services and many customers are asking Maintenance Technologies to work with them on productivity improvements in their manufacturing process'.
'In response to this we have developed a product called Freedom E Log to monitor any machine tool and display the data gathered to develop improvements in OEE (Overall Equipment Effectiveness).
We are pleased to talk to any machine tool user who is interested in using Freedom E Log to increase machining capacity'.
* About Cincinnati Machine - Cincinnati Machine Limited designs, builds and sources high-precision machine tools for the global aerospace, automotive, mould and die, medical and general machining markets.
The company offers technology-driven solutions that include 3-, 4- and 5-axis CNC horizontal and vertical machining centres; and vertical, horizontal and multi-axis turning centres.
Cincinnati Machine in Birmingham, UK is a division focused on the design, development, sales and marketing of the Cincinnati range of machine tools.
Cincinnati Machine is a division within MAG Industrial Automation Systems, headquartered in Michigan, USA.
Other divisions within MAG IAS include Cincinnati Technologies, serving the OEM and Tier 1 aerospace market; Powertrain Technologies, serving the global automotive market with customised high-production solutions; and Maintenance Technologies, responsible for the global after-sales and service parts market for all MAG IAS customers.
http://www.manufacturingtalk.com/news/cci/cci163.html
Entry Level CAD Based CMM Retrofit Software
A visit to any engineering site will reveal a vast array of machine tools, with an ongoing investment in new machines, modern tooling, CADCAM, DNC links, pallet loading, and much more - all purchased to fulfil specific production needs and to keep up with modern and future manufacturing requirements. A quick look into the inspection room often reveals a completely different story - the CMM. To the majority of companies, the CMM is a once in a lifetime opportunity to own the ultimate piece of inspection equipment, purchased with a view to solving a myriad of inspection problems. However, as manufacturing technology improves, the CMM quickly loses pace with Production requirements, and what was originally adequate software soon becomes limited in its capabilities. In particular, old software cannot cope with new operating systems, CAD integration or new probe technologies. The option to replace a machine is an obvious one, but totally unrealistic for many smaller companies. However, a much easier and cost-effective solution is possible - overnight, an out-dated machine can be turned into something as good as new, at a fraction of the cost of buying a new machine, with the added benefit of continuous software development that maintains your CMM’s status as a high technology measuring system.
Entry Level Software at an Affordable Price
The case for an entry-level CMM software retrofit is clearly evident. At present, users really only have 2 choices – high level software that is expensive to purchase, or cheap software that is simply not up to the job with little in the way of support or future development. With this in mind, the developers of Metrolog XG, the World’s leading CMM retrofit software, decided to package a CMM retrofit for entry level inspection applications, where all the “bells and whistles” of the market leading Metrolog XG are simply not required. “Many users will never have the need to use the latest technology, such as laser and scanning probes, but they still need access to a comprehensive CAD based measuring system that is supported by an experienced market leader,” commented Iain Caville, Managing Director of Measurement Solutions, the UK based distributor and support partner for Metrolog XG.
The all new Microlog XG CMM software has been developed specifically for smaller CMM’s and portable measuring arms, as these machines are generally used on relatively straightforward applications. With a fully integrated CAD engine to enable users to import 3D CAD models with ease, the software has been designed to provide operators with a simplified user interface that retains the most of the measuring power of higher cost, higher level software.
The two key elements of the software are ease of installation, and ease of use. Microlog XG is the first “plug and play” CMM software that directly interfaces with most makes and types of CMM controller. This means that any manual or CNC machine from manufacturers such as Hexagon, LK, Mitutoyo, Zeiss, Stiefelmayer, Wenzel, Sheffield, plus many others, can now be quickly upgraded without the need for expensive hardware upgrades. In those cases where the controller hardware is already obsolete, Measurement Solutions can offer a range of controller upgrades that can have a CNC machine up and running again within a few days. The software also lends itself ideally to portable measuring arms, with a suite of special tools dedicated to the type of measurements often performed with these devices. Once again, direct interfaces are readily available for all types of arm – Faro, Romer, Cimcore, Garda, etc.
The user interface has also been designed with simplicity in mind. Unlike traditional CMM software where numerous windows are often on display, Microlog XG only has 2 windows – a graphic CAD display, and a special Action Panel that is the only window requiring operator interaction. All common measuring functions have been allocated to the function keys on a standard PC keyboard, so the user has direct access to the measuring functions without the need to search through menus. During a measurement, the Action Panel displays real-time feedback with information regarding the quality of the measurement, if a bad point is taken, etc. Once a measurement is completed, the user can even go back and measure more points on the same feature to improve the quality of the data.
For repeat measurements, programming could not be easier, as the software automatically remembers what actions were taken, and then prompts the user to repeat the measurements. The program is saved in an easily readable format, so no programming ability is required from users. The program can be enhanced at any time with prompts that include pictures and operator instructions, making measurement simple, quick and reliable.
When a part has been measured, Microlog XG can export data for use in other software, just like most CMM software. However, this method requires operators to be proficient with other software applications, so Microlog XG also includes a unique Report Wizard, which gently guides the user from measurement result data to a high quality printed report that can include tabulated results, pictures of the part, result stickers, etc.
CAD or no CAD – Microlog XG Is Equally At Home
Microlog XG is equally at home with or without CAD data. If a CAD model is available, measurement results are automatically superimposed on the model. To measure a feature, the user simply chooses it by clicking on the CAD model, and then probes the feature accordingly – with a CNC machine, the software will automatically instruct the machine to measure the feature. However, even without CAD data, the software will routinely create a 3D drawing of the part being measured as each feature is being probed. These features can then be selected directly from the graphics screen in the case of constructions, distances and angles, etc.
Despite being described as “entry-level” software, Microlog XG still includes many powerful functionalities to deal with most applications, including measurement of free form surfaces, sections and profiles, calculation of basic GD&T, expansion and shrinkage, plus multiple alignments including best fit, RPS, geometric, etc. The software is also backed up by annual software updates, hotline telephone support by experienced CMM users, and a highly advanced help system.
“Most CMM’s in use today are mechanically sound, and still capable of producing perfectly good measurement data” says Iain Caville. “The problem really lies with the software, which has failed miserably to keep up with technological requirements. Now, we can offer CMM users a cost effective way to start using CAD based software, backed up by the World’s largest independent CMM software company”.
http://www.time-compression.com/x/guideArchiveArticle.html?id=9895
CNC retrofit revitalizes a tired VMC
A CNC RETROFIT ON A JOHNSFORD VMC IS INCREASING tire-mold manufacturing efficiency at King Machine 30% to 50%. The Akron, Ohio, company installed a Sinumerik 840Di control package consisting of drives, motors, and an AD14 board to interface with its external spindle system.
"We use the CNC for axismotion control, as well as spindle and auxiliary systems such as the toolchanger, lube system, and two rotary tables on the Johnsford," says Rob Snodgrass, programming manager at King. The machine does light milling and simultaneous 4/5-axis engraving on sidewall sections of tire molds, which measure between 25 and 60 in. in diameter and are made from 1020 steel or 6061 aluminum.
King internally stores both the mold part program and machine data on its own network. With a standard ethernet connection, the CNC accepts millions of lines of code in a few seconds. Operators at King then run an entire part program or block search to a specific area in the program instantly.
According to Snodgrass, the Sinumerik CNC is the fourth different control package the company has used on machines performing the same or similar work. He says, "Operators spent minimal time relearning the Johnsford VMC because the new control is familiar in feel and operation to our older controls."
Siemens Energy & Automation Inc.
ELK GROVE VILLAGE, ILL.
Shop secures crankshaft job
BEFORE IT COULD MACHINE 160,000 CRANKSHAFTS FOR A MAJOR ENGINE MANUFACTURER, Trace-A-Matic Corp. had to figure out how to hold the odd-shaped parts. So the Brookfield, Wis., shop contacted its distributor Engman-Taylor Co. of Minomonee Falls, Wis., for assistance. Engman-Taylor turned to Enerpac Workholding in Milwaukee for parts and technical expertise to build two workholding fixtures for the big job.
The fixtures consist of Enerpac's swing cylinders, block cylinders, and hydraulic work supports. In addition, the company supplied the necessary power unit for the fixtures to clamp parts consistently.
"The design of these fixtures was a cooperative effort between ourselves, our distributor, and Enerpac," says Karl Krueger, team leader at Trace-A-Matic. "We are especially grateful for the knowledge available from the manufacturer; it allowed us to purchase the right parts to properly build the fixtures."
Tooling shop delivers in days with new VMCs
ELITE MOLD & ENGINEERING BECAME the benchmark for other shops by building aluminum prototype tooling on a three-week basis. But that wasn't good enough. Its competitors caught up, so the Sterling Heights, Mich., shop has revamped its manufacturing philosophies and now measures deliveries in days.
To meet such short delivery times, Elite bids on jobs with high machining-to-labor ratios, incorporates the latest in software and computers, keeps a well-stocked toolroom, and makes efficient purchases with vendors. But probably the most significant change is a 60% reduction in machining time because of three Fadal Performance Series VMC 3020s with Siemens 840D controls.
"Typically, we run machines at 50 to 60 ipm, and a 60% increase seems like a drastic change," says Paul Patrash, general manager at Elite. "But with the 3020s and their controls, we now run 200 to 250 ipm at 10,000 rpm to produce good surface finishes and hold tolerances of 0.0002 in."
High-performance AC axis-drive motors and large-diameter, 40-mm ballscrews produce 3,800 lb of thrust, making the 3020 well suited for Elite's fast machining operations. Heavy cast iron boxways with nonmetallic liners provide maximum surface-area contact for vibration damping and rigidity. The boxways are hardened and ground, and the friction-free liners are on all gibs and way surfaces to ensure consistently tight machining tolerances. Positive-displacement lubrication over the full length of the way surfaces virtually eliminates machine stickslip.
The machine's Siemens 840D control executes programs fast for smooth surface finishes when contouring at high spindle speeds. It also has lookahead, dynamic feed forward, and programmable acceleration. Smoothed acceleration reduces wear on mechanical parts and optimizes travel response.
Using the 3020's contouring mode with programmed corner rounding, Elite quickly machines corners to reduce cycle time. A dynamic preprocessing buffer — first in, first out — increases program-execution speed. Programs are smaller, and spline interpolation using A, B, and C splines to generate smooth transitions makes for faster machining.
"To obtain long stretches of unattended machining and reduce the number of setups, mold halves are completed with a single setup," explains Ed Howell, shop supervisor at Elite. "Raw blocks are squared up, ejector systems completed, and part shapes are machined complete. On larger jobs, pairing up the VMCs lets us cut a cavity on one machine and a core on the other. These are some of the procedures that reduce our overall completion time."
While most machines require a cool-down period after running at maximum speed, the 3020 maintains a constant temperature with Cool Power, a special refrigerated cooling system that controls thermal growth and repeatability problems. A heat-transfer agent circulates through the machine spindle nose, around the spindle cartridge and headstock, and through the center of the gundrilled ballscrews.
This closed-loop system isolates the heat-transfer agent from chips and other contaminants. The heattransfer agent, which is monitored and chilled as required, maintains the temperature of positioning components to within ± 1° F of the VMC's ambient temperature. This minimizes thermal expansion and ensures consistent positioning repeatability, especially when machining molds with long cycle times.
Fadal Machining Centers
CHATSWORTH, CALIF.
Face mills keep HMC running at full capacity
TO HIKE THROUGHPUT OF GRAY CAST IRON PARTS, John Deere Waterloo Works, Waterloo, Iowa, forged close working partnerships between manufacturing engineers, a machine tool builder, and a tool supplier. Team members were charged with making the best use of the shop's new Mori Seiki MH-633 HMC to reduce cycle times and improve productivity of transmission covers. And a large portion of those improvements resulted from Sandvik Coromant's new milling technology.
The tooling company supplied a 3-in.-diameter CoroMill 290 face mill with 10 screwdown, siliconnitride inserts for roughing and another 290 with 6 silicon-nitride inserts and a single CB50 cubic-boronnitride (CBN) insert for finishing. The two-step/cutter process enables John Deere Waterloo Works to cut cycle time on its transmission covers 34%, exceeding original expectations.
While the old roughing process used silicon-nitride inserts, the 6-in.-diameter ISO-style milling cutters were unable to exploit the full power of the new machining center. However, the CoroMill 290 concept cutter is precision machined from hardened steel to minimize runout and withstand heavy cutting loads. In addition, the screwdown inserts are more accurate and stable than traditional clamp-in designs. The self-locating, screw-mounted inserts with carbide shims locate edges precisely and protect the cutter body. "The combination provides better repeatability with no presetting and more flexibility in cutter choices," says Curt Brown, the Sandvik Coromant representative working with John Deere.
The 3-in.-diameter 290 fits the new machine work envelope and lets Deere machine at full capacity. Roughing cuts run at 1,280 sfm with about a 0.014-in. chip load, which is much heavier than with the previous process.
The other 290 cutter with silicon-nitride inserts and a single CBN insert delivers fine finishes at Deere's high milling speeds. Extending 0.0005 in. beyond the silicon-nitride inserts, the CBN edge presents a wiper geometry with an extended face continuing after the cutting-nose radius.
This leading edge removes metal and produces a surface roughened by peaks and grooves. The extended face remains in contact with the work to wipe down or burnish away the peaks for a finish twice as smooth at the same surface speed or equally smooth at twice the surface speed.
Finishing cuts run at 3,500 sfm, again, about twice as fast as the old process. Feed is 0.006 ipr, and Deere is maxing-out the machine rpm and feedrates on some of the cuts but still getting a mirror finish. "We achieve better flatness and better finishes," comments Kallin Kurtz, project manager for cast iron redevelopment at John Deere.
Sandvik Coromant Co.
FAIR LAWN, N.J.
Drill's special geometry cuts machining costs
SWITCHING TO A NEW CARBIDE DRILL reduced the cost of drilling a hightemperature-alloy part by better than 80% for aerospace components manufacturer J.F. Fredericks Tool Co. in Farmington, Conn. The drills, Sculptured Edge (SE) 284 Dynapoints from Kennametal, sport a special positive-rake chisel point with an extremely large active cutting area that substantially reduces stress and provides freer chip flow on such hightemperature alloys.
"The bottom line is that these drills reduced our annual machining costs from $2,096 to $396," says Frank Klopp, manufacturing foreman at J.F. Fredericks. They eliminated a center-drilling and reaming operation, increased cutting speed to 75 sfm, and prolonged tool life to 150 pieces/regrind. But most importantly, drilling time dropped from 54 sec/part to 5.1.
Originally, it took three operations — center drilling, drilling, and reaming — to produce a 0.1875-in.-diameter hole in the Inconel 718 parts. Surface speed of the drilling operation was limited to 28 sfm, and the shop got an average of 18 pieces/regrind.
J.F. Fredericks runs the 284 Dynapoints on a Tsugami FMA5-II HMC. The part material has a 38-Rc hardness and is difficult to drill. "Its high nickel content makes it gummy, so it tends to chip or break inserts," says Klopp. "To avoid this, we ran our original cobalt-steel drills at relatively slow speeds and feeds, yet they would still chip or break around their flutes, cutting lips, or at the outside corners. The drills also walked or wandered at the beginning of the cut, so we had to use a center-drilling operation."
The special SE point on the 284 Dynapoint creates a smooth transition from the major cutting edge to the drill point. This lets the drill actively cut metal over the full distance from the center to the outer diameter. The drills are self-centering and rigid, which prevents them from walking or wandering at the beginning of a cut.
http://www.americanmachinist.com/304/Issue/Article/False/8316/Issue
CNC Retrofit Improves Tire Mold Machining
King (Akron, OH) recently installed a Siemens SINUMERIK 840Di control package; including drives, motors, and an ADI4 board to interface with its external spindle system. The Johnsford VMC is utilized to do light milling, as well as 4/5-axis simultaneous engraving on sidewall sections of tire molds. Typical King molds are 25"-60" O.D., made from 1020 steel or 6061 aluminum, sold to domestic and foreign tire manufacturers.
As Snodgrass explained, "We use the CNC for axis motion control, as well as spindle and auxiliary functions such as tool changer, lube system, and the two rotary tables on our Johnsford VMC. The Siemens Retrofit Group provided a turnkey solution, sending applications and field service engineers to our location to do the job, including several days of training. Plus, all our calls during post-processor development were answered immediately."
King internally stores both the mold part program and machine data information on its own networks. Using a standard Ethernet connection to an existing network, the CNC accepts millions of lines of code in a few seconds. King operators can then run the entire part program, or block search to a specific area in the program, instantly.
King operates multiple engraving centers at their facility and has documented the increase in efficiency, as a result of this CNC retrofit, according to Snodgrass.
The company operates a 33,000 sq.-ft. facility, which houses 4- and 5-axis engraving centers, both manual and CNC vertical turning lathes, manual and CNC horizontal milling centers, CNC vertical machining centers, small precision grinders, various drill presses, and sand blasting equipment.
Snodgrass observed the Siemens CNC was "the fourth different control package I’ve used over the years on machine tools, which perform the same or similar work to what we do here at King. The operators have needed to spend a minimal amount of time relearning the Johnsford VMC because the new control was very familiar in feel and operation to the older controls. It’s also been the first package to perform as advertised, from day one."
Tom Curfiss of the Siemens Retrofit Group states, "The SINUMERIK 840Di is built upon a standard Windows® NT platform and an industrial PC with Pentium™ processor, which allows the 840Di to streamline the process. It also enables users to increase productivity in a broad range of motion control applications, including milling, turning, grinding, robotics, material handling, welding operations, presses, laser cutting, and more."
http://www.manufacturingcenter.com/man/articles/m0803tire.htm
CNC Retrofit Improves Production And Saves Money
The start of 2005 was unlucky for the Honeywell Engine and Systems facility in Greer, South Carolina, when its three creep-feed grinders controlled by PLCs with positioning capability had become prone to failures and crashes. As a result, two of the machines were no longer in use. The facility turned to Brooklyn Technical Services (Brooklyn, Connecticut) after deciding to retrofit all the machines with CNCs. Brooklyn Technical Services specializes in the retrofit and rebuild of creep-feed grinders and roll grinders.
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| The control unit combines all CNC, HMI, PLC and communications tasks into a single panel control unit with Profibus interface to the I/O modules. |
“My objective here was to devise a cost-effective retrofit solution that would be easy for the machine operators to use,” explains Brooklyn Technical Services Owner Cliff Divine. He selected the Sinumerik 802D panel-based control system from Siemens Machine Tool Business (Elk Grove Village, Illinois) for this grinding application, because he says it provides a lot of value for the customer in a compact package. “Brooklyn Technical Services was one of the first retrofitters to use the 802D in a grinding application, and we had excellent results for our customers.”
Not only did the machines at Honeywell begin to work properly after the retrofit, but they also proved to be cost-effective. Because the machines already had Siemens analog servodrives and motor packages from a previous job Mr. Divine completed at Honeywell, the facility was able to save a significant amount of money. “By using a Siemens ADI4 interface board, we were able to use the existing servodrive and motors,” Mr. Divine says.
Brooklyn Technical Services initially developed a series of custom dressing and grinding cycles for this application. The cycles use a sequence of permanently definable user variables. In this case, the retrofitter was able to assign a series of plain text commands into the user data table. The value that the operator enters is stored until the value is changed by the operator, which, Mr. Divine notes, is an advantage over other controls that require entering this information at each cycle use.
Also, by using plain text, the operators are more readily able to recognize the use of each variable. “Who knows what the programmer has the user variable R20 designated for, or what letter ‘B’ signifies when in one cycle it might mean grinding feed rate and in another cycle it means dress amount?” Mr. Divine explains. “Simple language such as grinding feed rate, wheel surface speed and dress amount are much easier for the operator to understand. Also, there are fewer chances for error.”
He adds that Brooklyn Technical Services is able to place checks within the part programs to verify that the values entered by the operators fall within a specific range, thus preventing crashes and scrapped parts.
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| By using a single ADI4 interface board, the user is able to maintain all the servos and motors on the machine, thus saving money. |
The Sinumerik 802D combines all CNC, PLC, HMI and communication tasks in the panel control unit (PCU). This maintenance-free PCU integrates PC-based hardware and the Profibus interface for the drives and the I/O modules. The CNC can control up to four digital feed axes, and the spindle is also fully controlled by the PCU. In addition to the digital interface via Profibus, it also offers an analog interface for the spindle.
In Honeywell’s application, the CNC controls the axis and spindle movements of the creep-feed grinder. The programs are stored in the machine’s memory, and the CNC is linked to the host DNC at the customer location. “Because the user data are all plain text, and the values stored remain after each cycle, the operators find the setup to be very easy and fast,” Mr. Divine explains. “We provided setup programs that allowed the operators to jog the grinding wheel to the part, and automatically calculate and load the fixture offsets. Our initial dress program sets the wheel diameter and pre-dresses the form into the wheel without operator intervention. In fact, one of the night shift operators told us it was the easiest machine he’d ever run.”
Mr. Divine further notes that the CNC packages are adaptable to his machine needs. “Through the use of Siemens machine data tables, an integrator can easily enter the pertinent data on the machine. The manufacturer has already integrated most of the components. Through the use of function blocks in the PLC, there is little needed to set up the machine control panel or the setup panel—even the display is predefined.” This built-in integration, he adds, has saved him hundreds of hours of integration time.
Ease of use is only one of the many benefits the retrofit offers the machines at Honeywell. They are also much more efficient than they were prior to the retrofit. The machines have been running for almost a year since the retrofit, and not a single crash or machine failure has been reported. “It’s the best grinder I ever saw for $35,000 (the cost of the retrofit),” says Honeywell Manufacturing Engineer Dan Hicks.
The support from Siemens has also been impressive, according to Mr. Divine. “The people in the controls applications department are some of the best I’ve ever encountered. I’ve been working with CNCs on machine tools for more than 30 years and have dealt with all the major control suppliers in the industry. I chose to work exclusively with Siemens some years ago because of their application engineers. Often times, these engineers have been able to satisfy my requirements when other CNC suppliers said they could not.” He adds that he couldn’t be more satisfied with the results he has seen from the products and the people at Siemens.
Upgrading and Retrofitting PAC Machines
Are you spending a lot of time and money on secondary operations to clean up dross, remove bevel angle, or rework out of tolerance parts that were cut using plasma?
Does your cutting machine vibrate or occasionally act possessed?
Does it break down and stay down for days or weeks?
Is your CNC control outdated and slow?
If the answer to any of these questions is yes, you are not alone. Many fabrication shops are plagued by chronic problems with their cutting operations. Many of these problems can be eliminated through operator training and proper machine maintenance; others are best solved by equipment upgrades.
But before you relegate the whole cutting machine to the scrap heap, consider this: you may be able to get more out of your old machine by refurbishing or retrofitting critical components.
Plasma System Upgrades
A new plasma system retrofitted onto an older cutting machine or punch press can mean improved cut quality, increased cutting capacity, and faster cutting speeds.
Today's plasma systems offer significant improvements in power supply and torch technology including microprocessor-controlled power supplies, sophisticated gas flow controls and optimized torch and parts designs.
Consumable parts life has improved significantly with the use of inert start gases for oxygen plasma cutting.
Current and gas pressure ramping or stepping devices soften the plasma arc during ignition and cut off.
Optimized consumable designs specialized for plasma gas, amperage, and application along with improved manufacturing techniques have led to better cuts and the longer life from the torch parts.
Variables to consider
Material type will determine the plasma gas used.
- If you only cut stainless steel or aluminum, an older nitrogen plasma system may still be adequate for your needs. Air plasma may also be a viable lower cost alternative.
- For mild steel cutting, oxygen plasma is becoming the industry standard. Oxygen gives excellent cut quality and weldibility and also increases cutting speeds due to its reactivity with carbon steels.
- Air plasma offers similar cut quality on carbon steels, but may produce nitriding along the cut surface. Multi-gas plasma systems let you choose a plasma gas that is best for your material and application.
Material thickness will determine the size of plasma system needed
- The machine should have sufficient power to handle your typical cutting task with ease.
- Find out the thickest material that you regularly cut and select a system that will cut this material at a reasonably fast speed.
- Manufacturers rate their systems by maximum cut capacity from an edge start; pierce ratings are typically half the cut capacity.
| Material thickness | Recommended size of plasma system |
| Sheet metal <1/8" | 20-50 amps |
| Plate <1/4" | 50-100 amps |
| Plate <1/2" | 100-200 amps |
| Plate >1/2" | 200-1000 amps |
Hint: Don't skimp on power: In order to maintain fast cutting speeds make sure the system is big enough to handle your typical cutting jobs. For example, today's typical 100-amp air plasma system will cut mild steel at about 30-35 ipm. A 200-amp air system will pierce and cut the same material at 80 IPM and a 260-amp oxygen water injection system will cut it at approximately 100 IPM.
Cutting Machine Upgrades
Mechanical reconditioning
Although many advances have been made in cutting machine design in the last 25 years, many of the older gantry and cantilever style plasma cutting machines were well designed and remain viable. A good machine technician may be able to refurbish these machines and bring them back to life. Rack and pinion drives are now the most commonly used method of motion transmission. New gears and racks can be installed on older machines. Bearings to support the moving elements of the machine in longitudinal (the bridge moving along the rails) and transverse (the torch carriage moving along the bridge) axes are critical to smooth motion and accurate positioning of the cutter.
New drive package:
New servo motors, drive amplifiers, and encoders can be retrofitted to an old machine to replace outdated, worn, or unserviceable drive packages. PWM (Pulse width modulation) DC servo motors are typically used for plasma machines and are available as retrofit kits from automation manufacturers. These systems can be configured to retrofit many existing cutting machines. The newer drive packages offer greater positional accuracy, higher torque motors, and faster acceleration times.
New torch height controls:
Many older plasma machines were not equipped with adequate torch height control (THC) or if they were so equipped, the THC is no longer functional. Many shops simply do without this valuable tool. Most THC's are voltage regulated-that is they regulate position of the torch by sampling the arc voltage and comparing it to a preset value then driving the torch up or down to maintain that voltage and corresponding standoff. The latest THC's can control the standoff distance to within .005". Because the plasma arc column can be fixed to its optimum position to deliver a straight jet, this leads to substantial increases in cut quality, particularly bevel angle. Height controls also pay for themselves in reduced consumable useage. Most have an initial height sensing (IHS) function that allows an initial height to be set independently of arc voltage. This allows the operator to "pierce high and cut low", a practice that greatly enhances nozzle and shield life.
New CNC controls:
Retrofit options exist for most old cutting machine controls. Newer CNC controls offer more storage capacity, increased speed and accuracy, better programming features, faster communications, and more user friendly design. Most are industry standard, EIA and ESII code compatible and support third party pc software and part nesting programs. The latest generation of controls is PC-based to take advantage of the increased processing speed and lower cost of the industry standard computer processors. They use off-the-shelf computer components that are lower cost and open architecture in design. The best PC based controls offer communication rates as high as 230 kbaud, (10 times faster downloads than older models) gigabyte hard drives for file storage, and real-time graphic displays. Some can even receive software updates via e-mail (no e-proms or other firmware upgrades are necessary).
QUICK REVIEW:
- Upgrading and Retrofitting PAC Systems
- Points To Consider a Material type will determine the plasma gas used.
- Material thickness will determine the size of plasma system needed.
- Options To Consider
- Mechanical reconditioning
- New drive package
- New torch height controls
- New CNC controls
With a comprehensive refurbishment and upgrade of your existing plasma cutting system, it is possible to realize big gains in the productivity of your cutting operation and see an improvement in the bottom line without spending six figures on a new machine.
Retrofit CNC can double turret miller output
XYZ Machine Tools has announced that the popular and provenProtoTRAK Edge CNC controller is now available as a retrofitpackage. Whilst DROs are undoubtedly old technology - they havebeen around for more than thirty years - they are still provingpopular because they can easily and inexpensively be retrofittedto existing conventional machines and productivity besignificantly enhanced. The ProtoTRAK Edge controller is aseasily retrofitted to most turret mills and conventional kneemill but provides far greater productivity - typically output canbe doubled and in some applications trebled, and can parts can beproduced which cannot be attempted economically on a manual mill.It provides 2 axis CNC control and up to 4 axis DRO display.
TheProtoTRAK Edge uses plain English conversational programming, sothe operator does not need any CNC experience to use it.
Onlypart geometry has to be defined; the controller defines the toolpath automatically.
Using the teach option, the operator can turnmanual moves into programmed events automatically.
The Edgecontroller accepts CAM data from all the top brands of software.Set up is easy and simple.
Canned cycles include profiles, arcs,pockets, holes and frames.
19 maths help routines enable theoperator to quickly and easily calculate intersections,tangencies, centres etc, and are far easier to use than either acalculator or trig.
A parts library can be built up easily usingthe floppy drive; programs can be shared with other ProtoTRAKcontrollers.
The retrofit ProtoTRAK can be installed either byXYZ installation engineers or by a customer themselves.
The kitincludes the controller, motors, ballscrews, cables, brackets andtable guards.
A half day training - all that is needed - at anyone of XYZ's premises is included.
Parts warranty is fortwelve months; if XYZ engineers install the retrofit a twelvemonths labour warranty is also included.
Delivery is three weeksfrom order.
http://www.manufacturingtalk.com/news/xyz/xyz116.html
TheProtoTRAK Edge uses plain English conversational programming, sothe operator does not need any CNC experience to use it.
Onlypart geometry has to be defined; the controller defines the toolpath automatically.
Using the teach option, the operator can turnmanual moves into programmed events automatically.
The Edgecontroller accepts CAM data from all the top brands of software.Set up is easy and simple.
Canned cycles include profiles, arcs,pockets, holes and frames.
19 maths help routines enable theoperator to quickly and easily calculate intersections,tangencies, centres etc, and are far easier to use than either acalculator or trig.
A parts library can be built up easily usingthe floppy drive; programs can be shared with other ProtoTRAKcontrollers.
The retrofit ProtoTRAK can be installed either byXYZ installation engineers or by a customer themselves.
The kitincludes the controller, motors, ballscrews, cables, brackets andtable guards.
A half day training - all that is needed - at anyone of XYZ's premises is included.
Parts warranty is fortwelve months; if XYZ engineers install the retrofit a twelvemonths labour warranty is also included.
Delivery is three weeksfrom order.
http://www.manufacturingtalk.com/news/xyz/xyz116.html
Retrofit CNC makes machine as good as new
By simply retrofitting an Anilam 4200T CNC to a Lance vertical borer in place of defunct GE 1050 system, CSD Controls (UK) has returned the VTL to as good as new in terms of performance, accuracy and reliability. Established in 1994 by Colin Munn and Simon Hopkins, Malvern (Worcs) based CSD is an authorised Anilam retrofitter and over the years has specialised in breathing new life into machines of all types and sizes - 'often the types that other companies don't like to tackle', according to codirector Colin Munn. He continues: 'Our focus is control retrofitting and electrical re-engineering, but we do also carry out mechanical conversions and updates when required - it depends on what the customer wants'.
'But our reputation has been built on supplying cost-effective control system solutions, and the Lance VTL was no exception'.
In addition to supplying new drives for the spindle and axes, the retrofit of the Anilam 4200T CNC was described by Colin Munn as a 'straightforward' application.
With G code input with full text editor for cut, paste, search and replace, for example, plus interactive conversational G code help graphics and CAM programming, the Anilam 4200T CNC also features constant surface speed as standard feature, to help guarantee consistent surface finish and extended tool life.
The 4200T can run in several operational modes, including teach mode achieved via single or dual handwheel operation with dual axis interpolation.
Program utilities include create, delete/undelete, list, copy, rename and print, and the system's user-friendliness is prompted by full-screen editing and conversational help menu.
'We find that all our customers comment on the user-friendliness of the Anilam systems', adds Munn, 'especially first-time CNC users.
Another major factor in favour of these CNCs is the fact that Anilam's technical and applications support is excellent - this is very important when customers are new to CNC'.
http://www.engineeringtalk.com/news/ani/ani131.html
'But our reputation has been built on supplying cost-effective control system solutions, and the Lance VTL was no exception'.
In addition to supplying new drives for the spindle and axes, the retrofit of the Anilam 4200T CNC was described by Colin Munn as a 'straightforward' application.
With G code input with full text editor for cut, paste, search and replace, for example, plus interactive conversational G code help graphics and CAM programming, the Anilam 4200T CNC also features constant surface speed as standard feature, to help guarantee consistent surface finish and extended tool life.
The 4200T can run in several operational modes, including teach mode achieved via single or dual handwheel operation with dual axis interpolation.
Program utilities include create, delete/undelete, list, copy, rename and print, and the system's user-friendliness is prompted by full-screen editing and conversational help menu.
'We find that all our customers comment on the user-friendliness of the Anilam systems', adds Munn, 'especially first-time CNC users.
Another major factor in favour of these CNCs is the fact that Anilam's technical and applications support is excellent - this is very important when customers are new to CNC'.
http://www.engineeringtalk.com/news/ani/ani131.html
Control retrofit brings galaxy of benefits
By retrofitting an Anilam 4200T CNC to an ageing lathe, the UK Astronomy Technology Centre (ATC) has transformed what was "a difficult-to-operate piece of equipment that technicians were hesitant to use" into a user-friendly fully functional CNC turning machine. As a result, CNC turning with the Anilam control is now the preferred route for two-axis turning at the centre. Reflecting on the problems caused by the old controller Ewan Marshall, project technician at the Royal Observatory, Edinburgh ATC, says "Despite the fact that all the turning work is fairly straightforward two-axis machining, the old control was difficult to program, therefore it was not the most cost-effective method to manufacture the components, resulting in the machine not being used to its full potential".
Today, however, after Anilam's local agent, Inscot, retrofitted the 4200T, ATC engineers have at their disposal a powerful yet user-friendly (full-screen editing and conversational help menu) CNC system featuring G code input with full text editor for cut, paste, search and replace, for example, plus interactive conversational G code help graphics and CAM programming.
Program utilities on the 4200T include create, delete/undelete, list, copy, rename and print, and the system also features constant surface speed as standard, to help guarantee consistent surface finish and extended tool life.
Also, the control can run in several operational modes - including teach mode achieved via single or dual handwheel operation with dual axis interpolation.
Being well-versed in G code programming, the ATC operators describe the Anilam as a vast improvement compared to the former control, as technician George Davidson confirms: "In comparison to the previous CNC, which was a real nightmare, the Anilam guides us through everything.
We have extensive G code experience, so we tend to code in the job as we see it, rather than drawing it on the screen first".
"The Anilam CNC is really easy-to-use, so much so that the machine is now in more frequent use across a range of parts - which wasn't the case previously".
One example of the work being put through the new-look lathe is the beam steering mirror blanks required for the spectrometer focal plane unit within SPIRE (Spectral and Photometric Imaging Receiver), one of three instruments that will be carried on the European Space Agency's Herschel Space Observatory (formerly the Far Infra-Red and Submillimetre Telescope) scheduled for launch in 2007.
With its 3.5m primary mirror, it will be the biggest space telescope yet flown.
Designed for spectral and photometric observations at far infra-red and submillimetre wavelengths, SPIRE will investigate the statistics and physics of galaxy and structure formation in the early universe, and study the earliest stages of star formation.
SPIRE's focal plane unit - and therefore the mirror blanks - are critical components, and the blanks are rough and finish turned from 60mm diameter 6061 aluminium billets 90mm long before being switched to one of several milling machines-manual/DRO lathes for a variety of profile boring and milling, as well as part-off operations before being outsourced for diamond machining.
Machining includes the creation of a 'spectacle' feature and an opposing 'clamp' feature, as well as the production of a cavity face, various slots and the mirror face to an intermediate thickness of 10.55mm before diamond machining to create the mirror finish of 2 microns.
The turning and milling sequences are interspersed with two thermal cycling routines to stabilise the material structure for low temperature use.
With its mission "to help keep the UK at the forefront of world astronomy by providing a UK focus for the design, production and promotion of state-of-the-art astronomical technology", the ATC shares the old Royal Observatory Edinburgh site at Blackford Hill with the Edinburgh University Institute for Astronomy, and with 11 employees the machine shop plays a key role in the manufacture of the various spectrometers, telescopes and infra-red cameras produced for customers the world over, including the Isaac Newton Group, UKIRT and Gemini telescopes.
No two projects are the same, so batch sizes through the machine shop are small - often one-offs - and Ewan Marshall says ATC is like every other manufacturing organisation in that each contract has to be competitively priced, produced on time and delivered to specification (even though ATC operates with Government funding and in a non-profit-making mode).
As well as the impressive machine shop, ATC maintains its centre of excellence mantle via expert teams covering project science, project management, applied optics, and electronic and software engineering, and it invariably acts as the turnkey player in developing the specific solutions and designs (often in conjunction with universities at home and abroad) then determining and managing the appropriate manufacturing processes and lead time schedules.
Including administration, around 100 people are employed in the centre's CAD/CAM and electronic CAD, optical design, optical test laboratory, detector test facility and cleanroom, software development, machine shop, cryogenic and vacuum facilities, as well as the telescope simulator and fixture testing areas.
Many of the components produced are tested at -260C and 25G before final commissioning on site by ATC staff.
The machine shop traditionally handles the production of all components within a 500mm (cubed) envelope; anything larger that needs to be either machined or fabricated is outsourced along with specialist tasks such as gold plating and mirror-finish machining.
However, within the next few years the completion of a 4 million (pounds sterling) rebuilding project to create new workshops, laboratories and office space will enable ATC to handle larger projects, say up to 2m3.
"There are no plans to extend our machining capacity", says Ewan Marshall, "rather, the expansion will enable us to cope more easily with the assembly and test of larger projects, through the construction of buildings with high-ceilings and heavy overhead cranes".
Most of the material processed by the machine shop is aluminium (in addition to lightness it exhibits good thermal characteristics at low temperatures), with stainless steel and copper processed in lesser quantities and, interestingly, each operator is held totally responsible for the complete machining and resulting quality of the components he produces.
Every technician can work across either the CNC milling machines (which all feature Heidenhain CNCs) or the manual/DRO and CNC lathes in addition to handling a myriad of inspection routines as well as operating the co-ordinate measuring machine and assimilating the resultant QC data.
Also, each technician will plan and manage the production route of 'his' components to align with the master production schedule.
Machining work is evenly split between turning and milling.
"So", says Ewan Marshall in conclusion, "the updating of the lathe with the Anilam CNC was met with a huge sigh of relief by everyone.
Nobody had wanted to use the machine, but after Anilam's recommended training session, we were all conversant and comfortable with the control.
We now confidently use the machine whenever we can".
http://www.engineeringtalk.com/news/axg/axg100.html
Today, however, after Anilam's local agent, Inscot, retrofitted the 4200T, ATC engineers have at their disposal a powerful yet user-friendly (full-screen editing and conversational help menu) CNC system featuring G code input with full text editor for cut, paste, search and replace, for example, plus interactive conversational G code help graphics and CAM programming.
Program utilities on the 4200T include create, delete/undelete, list, copy, rename and print, and the system also features constant surface speed as standard, to help guarantee consistent surface finish and extended tool life.
Also, the control can run in several operational modes - including teach mode achieved via single or dual handwheel operation with dual axis interpolation.
Being well-versed in G code programming, the ATC operators describe the Anilam as a vast improvement compared to the former control, as technician George Davidson confirms: "In comparison to the previous CNC, which was a real nightmare, the Anilam guides us through everything.
We have extensive G code experience, so we tend to code in the job as we see it, rather than drawing it on the screen first".
"The Anilam CNC is really easy-to-use, so much so that the machine is now in more frequent use across a range of parts - which wasn't the case previously".
One example of the work being put through the new-look lathe is the beam steering mirror blanks required for the spectrometer focal plane unit within SPIRE (Spectral and Photometric Imaging Receiver), one of three instruments that will be carried on the European Space Agency's Herschel Space Observatory (formerly the Far Infra-Red and Submillimetre Telescope) scheduled for launch in 2007.
With its 3.5m primary mirror, it will be the biggest space telescope yet flown.
Designed for spectral and photometric observations at far infra-red and submillimetre wavelengths, SPIRE will investigate the statistics and physics of galaxy and structure formation in the early universe, and study the earliest stages of star formation.
SPIRE's focal plane unit - and therefore the mirror blanks - are critical components, and the blanks are rough and finish turned from 60mm diameter 6061 aluminium billets 90mm long before being switched to one of several milling machines-manual/DRO lathes for a variety of profile boring and milling, as well as part-off operations before being outsourced for diamond machining.
Machining includes the creation of a 'spectacle' feature and an opposing 'clamp' feature, as well as the production of a cavity face, various slots and the mirror face to an intermediate thickness of 10.55mm before diamond machining to create the mirror finish of 2 microns.
The turning and milling sequences are interspersed with two thermal cycling routines to stabilise the material structure for low temperature use.
With its mission "to help keep the UK at the forefront of world astronomy by providing a UK focus for the design, production and promotion of state-of-the-art astronomical technology", the ATC shares the old Royal Observatory Edinburgh site at Blackford Hill with the Edinburgh University Institute for Astronomy, and with 11 employees the machine shop plays a key role in the manufacture of the various spectrometers, telescopes and infra-red cameras produced for customers the world over, including the Isaac Newton Group, UKIRT and Gemini telescopes.
No two projects are the same, so batch sizes through the machine shop are small - often one-offs - and Ewan Marshall says ATC is like every other manufacturing organisation in that each contract has to be competitively priced, produced on time and delivered to specification (even though ATC operates with Government funding and in a non-profit-making mode).
As well as the impressive machine shop, ATC maintains its centre of excellence mantle via expert teams covering project science, project management, applied optics, and electronic and software engineering, and it invariably acts as the turnkey player in developing the specific solutions and designs (often in conjunction with universities at home and abroad) then determining and managing the appropriate manufacturing processes and lead time schedules.
Including administration, around 100 people are employed in the centre's CAD/CAM and electronic CAD, optical design, optical test laboratory, detector test facility and cleanroom, software development, machine shop, cryogenic and vacuum facilities, as well as the telescope simulator and fixture testing areas.
Many of the components produced are tested at -260C and 25G before final commissioning on site by ATC staff.
The machine shop traditionally handles the production of all components within a 500mm (cubed) envelope; anything larger that needs to be either machined or fabricated is outsourced along with specialist tasks such as gold plating and mirror-finish machining.
However, within the next few years the completion of a 4 million (pounds sterling) rebuilding project to create new workshops, laboratories and office space will enable ATC to handle larger projects, say up to 2m3.
"There are no plans to extend our machining capacity", says Ewan Marshall, "rather, the expansion will enable us to cope more easily with the assembly and test of larger projects, through the construction of buildings with high-ceilings and heavy overhead cranes".
Most of the material processed by the machine shop is aluminium (in addition to lightness it exhibits good thermal characteristics at low temperatures), with stainless steel and copper processed in lesser quantities and, interestingly, each operator is held totally responsible for the complete machining and resulting quality of the components he produces.
Every technician can work across either the CNC milling machines (which all feature Heidenhain CNCs) or the manual/DRO and CNC lathes in addition to handling a myriad of inspection routines as well as operating the co-ordinate measuring machine and assimilating the resultant QC data.
Also, each technician will plan and manage the production route of 'his' components to align with the master production schedule.
Machining work is evenly split between turning and milling.
"So", says Ewan Marshall in conclusion, "the updating of the lathe with the Anilam CNC was met with a huge sigh of relief by everyone.
Nobody had wanted to use the machine, but after Anilam's recommended training session, we were all conversant and comfortable with the control.
We now confidently use the machine whenever we can".
http://www.engineeringtalk.com/news/axg/axg100.html
Retrofit robot produces unmanned turning centre
Virtually any make of CNC turning machine can be transformed into an unmanned production centre by retrofitting a new, robotic cell from Fastems. Designated RPC-16G, it automates loading and unloading of workpieces into and out of the machine spindle, resulting in increased production efficiency and reduced staffing costs. Each cell is purpose-built in Finland for the specific application and is installed and commissioned by Fastems' UK subsidiary in Dartford.
The package comes complete with workpiece grippers and includes a cylinder kit for automating the opening and closing of the lathe door.
Control is based on a Fanuc RJ3iB, which is interfaced with the machine's CNC system.
The gantry-type unit's storage system sits at the end of the lathe, away from the working area, allowing better access for proving-out a new job than is afforded by an articulated-arm robot system sitting in front of the lathe.
Installation time is short, contributing to quick start-up and hence rapid return on investment.
Measuring just (L) 3.3m x (W) 2.0m x (H) 2.6m, the compact cell is equipped with a Fanuc M-16iT industrial robot that can handle workpieces up to 13kg, or 2 x 6kg to allow load and unload in a single visit to the lathe's machining area.
Two material trolleys for Euro pallets and component locators, capable of carrying up to one tonne apiece, are incorporated within the enclosure for stocking raw billets and machined parts.
With its short changeover time, compact design and easy access for lathe maintenance, the cell has been developed with the needs of subcontractors firmly in mind, allowing them to grow into automation as business dictates without having to make an unnecessarily high front-end investment.
http://www.manufacturingtalk.com/news/fas/fas122.html
The package comes complete with workpiece grippers and includes a cylinder kit for automating the opening and closing of the lathe door.
Control is based on a Fanuc RJ3iB, which is interfaced with the machine's CNC system.
The gantry-type unit's storage system sits at the end of the lathe, away from the working area, allowing better access for proving-out a new job than is afforded by an articulated-arm robot system sitting in front of the lathe.
Installation time is short, contributing to quick start-up and hence rapid return on investment.
Measuring just (L) 3.3m x (W) 2.0m x (H) 2.6m, the compact cell is equipped with a Fanuc M-16iT industrial robot that can handle workpieces up to 13kg, or 2 x 6kg to allow load and unload in a single visit to the lathe's machining area.
Two material trolleys for Euro pallets and component locators, capable of carrying up to one tonne apiece, are incorporated within the enclosure for stocking raw billets and machined parts.
With its short changeover time, compact design and easy access for lathe maintenance, the cell has been developed with the needs of subcontractors firmly in mind, allowing them to grow into automation as business dictates without having to make an unnecessarily high front-end investment.
http://www.manufacturingtalk.com/news/fas/fas122.html
Retrofit CNCs convert analogue lathes
With a 150-year history, globally renowned lathe manufacturer Dean Smith and Grace has plenty of experience when it comes to selecting key supplier partners to work on its machine tool products. However, in recent times the newly appointed management team at DSG re-evaluated its best methods for taking the company forward. Strategy regarding new build machines was deemed straightforward, but a way of generating a profitable retrofit enterprise from its abundant fleet of ageing lathes in the field, was proving more difficult.
However, following discussions with Siemens Automation and Drives, a control and software solution was offered that overcame all of the difficulties faced.
'We basically required a mode of converting analogue-based lathes into modern, CNC-controlled machine tools without incurring excessive costs,' explains Nigel Grainger, managing director of DSG.
'I visited the Siemens stand at the MACH 2004 exhibition and they recommended their Sinumerik 840Di with Shopturn job shop software.' One of the Siemens staff members on the stand that day was sales manager Andy Hodgson, who takes up the story: 'The DSG analogue lathes use Philips control equipment.
We demonstrated to Nigel our 840Di CNC system explaining its extensive range of features including the analogue signal feature that allows it to interface with any make or model of drive system using analogue commands.
He was so impressed he bought our exhibition unit there and then.
Since the show, DSG has taken five further units and is now looking at Siemens controls and drives for new build DSG machines.
The Sinumerik 840Di with Shopturn solution offered by Siemens allows DSG to refurbish its lathes, returning them to 'as new' capability.
'It has proved to be very cost effective for us,' continues Grainger, 'Which means in turn we can offer a low-cost upgrade option to any user of a DSG lathe built since the mid-1970s.' One such user is Neophix Engineering, a Keighley, UK-based manufacturer of products such as connecting clamps, hose clamps, mounting straps, retaining straps and V-profile clamps for industries such as earthmoving, motorsport, food processing, telecommunications, marine, nuclear, mining and petrochemical.
The company uses a DSG 1508 lathe fitted with Siemens controls to manufacture components in large batches.
'We are very pleased with the machine,' says Jonathan Driver of Neophix.
'It has met all of our expectations and more.
The control is particularly impressive.' The 840Di is a totally integrated system built upon a standard Windows XP platform and an industrial PC with a Pentium processor, all of which amounts to greater speed, accuracy and flexibility.
Shopturn software reduces set-up time because workpiece programming and tool measurements are reduced to a few button pushes, while programming errors can easily be identified and corrected before cutting begins.
The simple and logical format of the interface and the intuitive structure of its operating commands and routines enable operators to program workpieces graphically and without prior G-code training.
The use of the 840Di with Shopturn has extended the capability of DSG lathes considerably.
According to Grainger, the system's functionality, ease of use and expanded memory capacity, make the company's machines an altogether more adept range of products.
Thus far, DSG has incorporated the Siemens retrofit solution on to its 1508 and 2413 range of two-axis centre lathes, and now offers Siemens as an option on new build machines.
'Overall we are very pleased with the system,' he concludes.
'Our customers like it and we like it - it has definitely helped DSG to win new orders.'
http://www.manufacturingtalk.com/news/sie/sie154.html
However, following discussions with Siemens Automation and Drives, a control and software solution was offered that overcame all of the difficulties faced.
'We basically required a mode of converting analogue-based lathes into modern, CNC-controlled machine tools without incurring excessive costs,' explains Nigel Grainger, managing director of DSG.
'I visited the Siemens stand at the MACH 2004 exhibition and they recommended their Sinumerik 840Di with Shopturn job shop software.' One of the Siemens staff members on the stand that day was sales manager Andy Hodgson, who takes up the story: 'The DSG analogue lathes use Philips control equipment.
We demonstrated to Nigel our 840Di CNC system explaining its extensive range of features including the analogue signal feature that allows it to interface with any make or model of drive system using analogue commands.
He was so impressed he bought our exhibition unit there and then.
Since the show, DSG has taken five further units and is now looking at Siemens controls and drives for new build DSG machines.
The Sinumerik 840Di with Shopturn solution offered by Siemens allows DSG to refurbish its lathes, returning them to 'as new' capability.
'It has proved to be very cost effective for us,' continues Grainger, 'Which means in turn we can offer a low-cost upgrade option to any user of a DSG lathe built since the mid-1970s.' One such user is Neophix Engineering, a Keighley, UK-based manufacturer of products such as connecting clamps, hose clamps, mounting straps, retaining straps and V-profile clamps for industries such as earthmoving, motorsport, food processing, telecommunications, marine, nuclear, mining and petrochemical.
The company uses a DSG 1508 lathe fitted with Siemens controls to manufacture components in large batches.
'We are very pleased with the machine,' says Jonathan Driver of Neophix.
'It has met all of our expectations and more.
The control is particularly impressive.' The 840Di is a totally integrated system built upon a standard Windows XP platform and an industrial PC with a Pentium processor, all of which amounts to greater speed, accuracy and flexibility.
Shopturn software reduces set-up time because workpiece programming and tool measurements are reduced to a few button pushes, while programming errors can easily be identified and corrected before cutting begins.
The simple and logical format of the interface and the intuitive structure of its operating commands and routines enable operators to program workpieces graphically and without prior G-code training.
The use of the 840Di with Shopturn has extended the capability of DSG lathes considerably.
According to Grainger, the system's functionality, ease of use and expanded memory capacity, make the company's machines an altogether more adept range of products.
Thus far, DSG has incorporated the Siemens retrofit solution on to its 1508 and 2413 range of two-axis centre lathes, and now offers Siemens as an option on new build machines.
'Overall we are very pleased with the system,' he concludes.
'Our customers like it and we like it - it has definitely helped DSG to win new orders.'
http://www.manufacturingtalk.com/news/sie/sie154.html
Milling CNC retrofit boosts surface grinder usage
A three-axis Anilam CNC control system more usually found controlling milling machines has transformed the capability of a rebuilt Jones and Shipman 540 toolroom surface grinder at tooling manufacturer, Electro-spark. The grinder, which before being rebuilt was a manual machine, has enabled the Cwmbran (South Wales) company to reduce cycle times and improve quality levels in the production of components which are now machined under full three-axis (X, Y and Z) control with the Anilam system. The machine has been completely rebuilt and fitted with DC drives on all three axes, with the drives being controlled by the Anilam MK 3300 CNC.
Also, the original 1.1kW grinding wheel spindle drive motor has been replaced by a 3.7kW motor which drives the spindle through a poly-vee belt.
As a result of the new drives and larger motor - and in combination with the fine degree of positional and rotational control provided by the Anilam CNC - the machine is now being used also for creep feed grinding.
The benefit of this is illustrated by Electro-spark managing director, Dave Calder, who quotes one of the first jobs carried out on the refurbished machine.
'The component was previously ground by multiple passes and small downfeed movements of the wheel,' he says.
'With 50 ground in one set-up, the production rate was then 350 parts an hour.
'On the new machine, however, a 0.020in deep cut is used to enable the work to be completed in one pass and, as a result, throughput has risen to 600 an hour.
Component quality has improved too, because there is no longer the disturbance of the work by wheel contact at the beginning of each pass as with reciprocal grinding.
'Also, because of the greater degree of control on feed rate and positioning, it is possible to fast feed the wheel close to the point of cutting before reducing to the creep feed rate.
This has also contributed to the improved cycle time.' While Electro-spark provides a sub-contract tool making service, its primary role is making tooling components for one of its sister companies, Iron-spray, which manufactures tools in volume for use in carpet-making and weaving machines.
It cost Dave Calder GBP22,000 to have the machine rebuilt and the CNC integrated.
The Anilam retrofitting, which included fitting new ballscrews and drives, was carried out by Machine tool control of Pontypool, South Wales - Anilam's representative in Wales and a specialist in CNC retrofitting with over 20 years experience in the sales and support of the Anilam product range.
'To buy a new CNC machine with a comparable CNC would have cost three times as much, and the machine would have been too big for the light precision work we now do on it,' reckons Dave Calder.
'Due to its success there are now plans to have a second grinding machine rebuilt for control by a two-axis Anilam MK 3200 unit.' As well as being good value for money, the rebuild and retrofit has provided Electro-spark with a type of machine control well suited to its toolmakers' style of working.
'It is programmed logically in the way the machine operator thinks,' continues Dave Calder.
'He simply tells the CNC what he thinks the machine needs to do.
He can have a picture of the operations in his mind, as if he were turning the handles.
Nor does making a single movement change to a program affect any other movements that are part of an operating cycle.' The grinder is permanently fitted with a fixturing system to which all sub-fixtures accurately locate; this facilitates the transfer of workpieces to milling and EDM machines.
The axial position of the main fixture on the grinder is precisely known so that its relationship to the grinding wheel can be accurately determined by the CNC.
'The operator brings the wheel to where the cutting will start and sets the zero position.
After that, all the movements can be programmed in sequence.
The average job takes about ten minutes and it is so logical.
All the programs we have so far created are stored in the CNC's ample memory.' The versatility of the retrofit machine and its new controller is illustrated by one example which involved grinding a group of identical parts as one set-up.
When completed on a manual grinder the fixture had a small error in alignment so the height of the last piece differed from the first by 0.002in.
This was compensated for by grinding the middle part to size then the first and last on top and bottom limits.
'We put it on the new machine and programmed the Anilam to give a 0.002in fall along the length of the batch,' says Dave Calder.
'When we checked them they were all parallel and in tolerance.
From then on the operator felt fully at home with the control; it is so user friendly.
I know we should have corrected the fixture in the first place, but now there is no need to.' In addition to tool steel, tungsten and exotic metals, the machine also grinds ceramics.
For holding these non-magnetic materials, Electro-spark has recently started using the Cryotech ice-chuck.
This system was developed in Switzerland and last year the product and name was purchased by Dave Calder to enable him to manufacture and market the novel workholding device.
The Cryotech ice chuck creates a holding force of 15kg/cm2, sufficient for machining by grinding and other methods.
With the workpiece placed on the wetted chuck surface, the water is frozen using microprocessor control and as it turns to ice it securely holds the workpiece.
The complexity of work now possible on the Jones and Shipman machine, and in this particular instance with the aid of the Cryotech ice chuck, is shown in its ability to grind a very thin plate that has a three-dimensional crowned surface.
This called for the 100mm square plate to be held firmly and to have its top surface crowned in both directions, using both longitudinal and transverse table movements to form part of the spherical surface.
All the wheel and table movements needed to achieve the shape were programmed sequentially into the Anilam CNC by the operator to create the precise form.
http://www.manufacturingtalk.com/news/aie/aie142.html
Also, the original 1.1kW grinding wheel spindle drive motor has been replaced by a 3.7kW motor which drives the spindle through a poly-vee belt.
As a result of the new drives and larger motor - and in combination with the fine degree of positional and rotational control provided by the Anilam CNC - the machine is now being used also for creep feed grinding.
The benefit of this is illustrated by Electro-spark managing director, Dave Calder, who quotes one of the first jobs carried out on the refurbished machine.
'The component was previously ground by multiple passes and small downfeed movements of the wheel,' he says.
'With 50 ground in one set-up, the production rate was then 350 parts an hour.
'On the new machine, however, a 0.020in deep cut is used to enable the work to be completed in one pass and, as a result, throughput has risen to 600 an hour.
Component quality has improved too, because there is no longer the disturbance of the work by wheel contact at the beginning of each pass as with reciprocal grinding.
'Also, because of the greater degree of control on feed rate and positioning, it is possible to fast feed the wheel close to the point of cutting before reducing to the creep feed rate.
This has also contributed to the improved cycle time.' While Electro-spark provides a sub-contract tool making service, its primary role is making tooling components for one of its sister companies, Iron-spray, which manufactures tools in volume for use in carpet-making and weaving machines.
It cost Dave Calder GBP22,000 to have the machine rebuilt and the CNC integrated.
The Anilam retrofitting, which included fitting new ballscrews and drives, was carried out by Machine tool control of Pontypool, South Wales - Anilam's representative in Wales and a specialist in CNC retrofitting with over 20 years experience in the sales and support of the Anilam product range.
'To buy a new CNC machine with a comparable CNC would have cost three times as much, and the machine would have been too big for the light precision work we now do on it,' reckons Dave Calder.
'Due to its success there are now plans to have a second grinding machine rebuilt for control by a two-axis Anilam MK 3200 unit.' As well as being good value for money, the rebuild and retrofit has provided Electro-spark with a type of machine control well suited to its toolmakers' style of working.
'It is programmed logically in the way the machine operator thinks,' continues Dave Calder.
'He simply tells the CNC what he thinks the machine needs to do.
He can have a picture of the operations in his mind, as if he were turning the handles.
Nor does making a single movement change to a program affect any other movements that are part of an operating cycle.' The grinder is permanently fitted with a fixturing system to which all sub-fixtures accurately locate; this facilitates the transfer of workpieces to milling and EDM machines.
The axial position of the main fixture on the grinder is precisely known so that its relationship to the grinding wheel can be accurately determined by the CNC.
'The operator brings the wheel to where the cutting will start and sets the zero position.
After that, all the movements can be programmed in sequence.
The average job takes about ten minutes and it is so logical.
All the programs we have so far created are stored in the CNC's ample memory.' The versatility of the retrofit machine and its new controller is illustrated by one example which involved grinding a group of identical parts as one set-up.
When completed on a manual grinder the fixture had a small error in alignment so the height of the last piece differed from the first by 0.002in.
This was compensated for by grinding the middle part to size then the first and last on top and bottom limits.
'We put it on the new machine and programmed the Anilam to give a 0.002in fall along the length of the batch,' says Dave Calder.
'When we checked them they were all parallel and in tolerance.
From then on the operator felt fully at home with the control; it is so user friendly.
I know we should have corrected the fixture in the first place, but now there is no need to.' In addition to tool steel, tungsten and exotic metals, the machine also grinds ceramics.
For holding these non-magnetic materials, Electro-spark has recently started using the Cryotech ice-chuck.
This system was developed in Switzerland and last year the product and name was purchased by Dave Calder to enable him to manufacture and market the novel workholding device.
The Cryotech ice chuck creates a holding force of 15kg/cm2, sufficient for machining by grinding and other methods.
With the workpiece placed on the wetted chuck surface, the water is frozen using microprocessor control and as it turns to ice it securely holds the workpiece.
The complexity of work now possible on the Jones and Shipman machine, and in this particular instance with the aid of the Cryotech ice chuck, is shown in its ability to grind a very thin plate that has a three-dimensional crowned surface.
This called for the 100mm square plate to be held firmly and to have its top surface crowned in both directions, using both longitudinal and transverse table movements to form part of the spherical surface.
All the wheel and table movements needed to achieve the shape were programmed sequentially into the Anilam CNC by the operator to create the precise form.
http://www.manufacturingtalk.com/news/aie/aie142.html
Retrofit latest barfeeds and reduce machine cycles
Being the sole manufacturer and number one barfeed supplier in the UK, Hydrafeed have fitted their units to almost every type of CNC lathe available, both in the UK, and overseas. They are the main supplier to all major machine tool dealers in the UK, and are one of the most reliable companies when the question of retrofitting is raised. With over 15 years experience in the field of Barfeed retrofits, the service provided is heavily detailed and completed to the exact specifications set out by the customer at the start of the project.
Before accepting a retrofit project, the Hydrafeed team arranges a convenient visit to the customer1s premises, in order to undertake the following 1.
Obtain photos of the customer's site.
2) Obtain full measurement details for CNC Lathe.
3) Obtain complete electrical specifications for Interfacing.
4) Obtain details of customer's job requirements / specifications.
Upon return to site, the Hydrafeed team will then review all the above points, in order to confirm that all criteria can be met, and that the customer can be given the complete package that they have requested.
The team then contacts the customer outlining all costs, time scales, and outlining points that the customer will need to be aware of in order for the whole retrofit to run smoothly.
Over the years, Hydrafeed has retrofitted their Barfeeds to many customers including G-Mach Engineering, John Hall Engineering, and RGS Electro Pneumatics.
Graham Miller of Melton Mowbray based G-Mach Engineering comments, 'We originally had a long Barfeed on our Lathe, and decided to move in onto another Lathe.
We then contacted Hydrafeed with details on a particular application that we wished to run.
Hydrafeed provided us with a complete package to suit the application we required, and a complete retrofit of one of the Multifeed Short Magazine Barfeeds on to the Hitachi Lathe was undertaken.
Since it1s installation in September last year, the package has not stopped running, and has proved to be extremely useful in cutting cycle times, and increasing turnover.
The retrofit of the Multifeed Barfeed was quick, easy and very professional by Hydrafeed.' Martin Hall of John Hall Engineering in Bridlington explains, 'A component drawing was sent to Hydrafeed who quickly diagnosed possible problems with the application.
These problems were resolved almost immediately, and the Multifeed Barfeed was installed on to our Tornado Lathe.
The cycle time has been reduced by 25%, and the machine now runs for 10 hours a day, with the operator running another machine.
From my initial request for literature, through to installation, Hydrafeed have been both efficient and professional.' Tony Watson of RGS Electro Pneumatics, based in Oswaldthistle reveals, 'RGS has seven lathes, and operates the machines with 1-2 setter / operators at any one time - two of these lathes had single Barfeeds on them.
We decided to replace the Barfeeds with two Multifeed units, to create longer continuous running, and the facility for lights out running on the two Nakamura TW10s.
We contacted Hydrafeed, and within two weeks from order, the Barfeeds were specified, installed, and interfaced (installation and interfacing carried out over a two day period, including operator training).
This was all done in a very quick, methodical and professional manner from start to finish, and we are now beginning to see the benefits of using Hydrafeed for this retrofit.' With their highly trained team, a massive wealth of experience in the field of Barfeed retrofitting, and with many satisfied customers, Hydrafeed can provide the complete package to suit all types of applications, providing maximum support and reliability, with minimum effort and worry, all at a price second to none in the Barfeed industry.
http://www.manufacturingtalk.com/news/hdr/hdr105.html
Before accepting a retrofit project, the Hydrafeed team arranges a convenient visit to the customer1s premises, in order to undertake the following 1.
Obtain photos of the customer's site.
2) Obtain full measurement details for CNC Lathe.
3) Obtain complete electrical specifications for Interfacing.
4) Obtain details of customer's job requirements / specifications.
Upon return to site, the Hydrafeed team will then review all the above points, in order to confirm that all criteria can be met, and that the customer can be given the complete package that they have requested.
The team then contacts the customer outlining all costs, time scales, and outlining points that the customer will need to be aware of in order for the whole retrofit to run smoothly.
Over the years, Hydrafeed has retrofitted their Barfeeds to many customers including G-Mach Engineering, John Hall Engineering, and RGS Electro Pneumatics.
Graham Miller of Melton Mowbray based G-Mach Engineering comments, 'We originally had a long Barfeed on our Lathe, and decided to move in onto another Lathe.
We then contacted Hydrafeed with details on a particular application that we wished to run.
Hydrafeed provided us with a complete package to suit the application we required, and a complete retrofit of one of the Multifeed Short Magazine Barfeeds on to the Hitachi Lathe was undertaken.
Since it1s installation in September last year, the package has not stopped running, and has proved to be extremely useful in cutting cycle times, and increasing turnover.
The retrofit of the Multifeed Barfeed was quick, easy and very professional by Hydrafeed.' Martin Hall of John Hall Engineering in Bridlington explains, 'A component drawing was sent to Hydrafeed who quickly diagnosed possible problems with the application.
These problems were resolved almost immediately, and the Multifeed Barfeed was installed on to our Tornado Lathe.
The cycle time has been reduced by 25%, and the machine now runs for 10 hours a day, with the operator running another machine.
From my initial request for literature, through to installation, Hydrafeed have been both efficient and professional.' Tony Watson of RGS Electro Pneumatics, based in Oswaldthistle reveals, 'RGS has seven lathes, and operates the machines with 1-2 setter / operators at any one time - two of these lathes had single Barfeeds on them.
We decided to replace the Barfeeds with two Multifeed units, to create longer continuous running, and the facility for lights out running on the two Nakamura TW10s.
We contacted Hydrafeed, and within two weeks from order, the Barfeeds were specified, installed, and interfaced (installation and interfacing carried out over a two day period, including operator training).
This was all done in a very quick, methodical and professional manner from start to finish, and we are now beginning to see the benefits of using Hydrafeed for this retrofit.' With their highly trained team, a massive wealth of experience in the field of Barfeed retrofitting, and with many satisfied customers, Hydrafeed can provide the complete package to suit all types of applications, providing maximum support and reliability, with minimum effort and worry, all at a price second to none in the Barfeed industry.
http://www.manufacturingtalk.com/news/hdr/hdr105.html
Retrofitted CNC raises productivity by 11%
Eaton engineers have reported 11% increase in overall productivity of a Heald grinder, plus improved throughput and enhanced accuracy since retrofitting an up-to-date CNC. Eaton Corporation‚s facility in Roxboro, North Carolina is a major supplier of hydraulic lifters and associated components for the automotive market. A key machine tool in their operation is the Heald 1VL, an I.D.
grinder utilized for the finish grinding operation on these critical engine components.
This Heald grinder was originally equipped with an early generation Siemens 3G CNC, used to control the X/Z linear axes, high-speed grinding and dressing spindles (60,000 and 54,000 rev/min, respectively) and an automatic load/unload device.
Also, the original design of the machine incorporated size gauging and control.
The older CNC was built in the 1980s, specifically designed for the operational parameters of the grinder and had adequate power and flexibility for its time.
With internal dressing and size control functionality, it had performed adequately at Eaton for many years.
As with all controls, however, it eventually became more difficult to maintain and downtime became an issue for Eaton engineers.
After careful examination of the available controls, as well as the main frame and other mechanical components onboard, the decision was made to retrofit for improved efficiency and on-pace production.
Eaton and Ex-Cell-O (Sterling Heights, Michigan, USA) collaborated on this retrofit project.
They approached the task from a joint venture perspective, in the sense that Ex-Cell-O would manage the controls integration, machine software, interface design, electrical design and implementation of the new system, while Eaton would manage the mechanical aspects of the project.
Eaton would furnish most of the major new components that were already inventories, i.e, those not associated with the control system.
These included relays, switches, terminals and other items that would be reused from the original design, where possible.
The original electrical cabinets would also be reused, it was decided.
Since Siemens, the CNC supplier in Elk Grove Village, Illinois, no longer made a dedicated control for the grinder, a suitable CNC was selected from the current standard line of Siemens product.
The Sinumerik 810D CNC was chosen for the following reasons, as determined by Eaton and Ex-Cell-O engineers: * Compact design - drives and controls are in the same package, resulting in a considerable space savings.
* Digital axis drives - digital drives and absolute encoders minimized hardware and had definitive size advantages for the application.
* HMI interface - compact design of the CNC control interface kept the control console in the same package.
* Custom cycles - Siemens cycle programming eliminated some programming of grinding cycles.
* Imbedded PLC - powerful Siemens Step 7 imbedded PLC controller further enhanced the HMI protocol.
The original Heald grinder controls console required some redesign, as the Siemens Sinumerik 810D control panels are slightly wider than the original System 3.
However, the redesign was achieved, with the capability of mounting to the existing pendant support art on the machine.
The PLC interface was accomplished with Step 7 PLC logic with separate I/O Siemens hardware that provided a more compact design and easily interfaced with the existing I/O terminal connectors.
The Sinumerik 810D is a compact, PC-based control that is used for simple to medium-range CNC applications.
It features an integrated NC, PLC and is capable of handling up to six axes and two spindles.
SIMATIC PLC consists of standard hardware and software components that can be individually tailored to the task at hand.
It is the standard automation system for controlling the widest variety of machines and plants.
The existing program format was used to maintain the operator compatibility with the old programs.
The old programs were approximately 75% transportable with modifications implemented to those areas that required new functionality.
This minimized operator impact with new equipment since the operator controls and the program parameters were basically the same as the old equipment.
Special operator interface screens were designed to match the original parameter values, reducing the need for extensive training of the operator interface system.
Fault and Operator Messages were programmed to minimize downtime and give as much information as possible to the operator and maintenance personnel.
Eaton engineers Rick Gentry and Jim Guess have reported over 11% increases in the overall productivity of the Heald grinder, with the additional advantages of improved throughput and enhanced accuracy since the retrofit.
The retrofit project at Eaton required approximately six weeks to implement and obtain customer approval.
grinder utilized for the finish grinding operation on these critical engine components.
This Heald grinder was originally equipped with an early generation Siemens 3G CNC, used to control the X/Z linear axes, high-speed grinding and dressing spindles (60,000 and 54,000 rev/min, respectively) and an automatic load/unload device.
Also, the original design of the machine incorporated size gauging and control.
The older CNC was built in the 1980s, specifically designed for the operational parameters of the grinder and had adequate power and flexibility for its time.
With internal dressing and size control functionality, it had performed adequately at Eaton for many years.
As with all controls, however, it eventually became more difficult to maintain and downtime became an issue for Eaton engineers.
After careful examination of the available controls, as well as the main frame and other mechanical components onboard, the decision was made to retrofit for improved efficiency and on-pace production.
Eaton and Ex-Cell-O (Sterling Heights, Michigan, USA) collaborated on this retrofit project.
They approached the task from a joint venture perspective, in the sense that Ex-Cell-O would manage the controls integration, machine software, interface design, electrical design and implementation of the new system, while Eaton would manage the mechanical aspects of the project.
Eaton would furnish most of the major new components that were already inventories, i.e, those not associated with the control system.
These included relays, switches, terminals and other items that would be reused from the original design, where possible.
The original electrical cabinets would also be reused, it was decided.
Since Siemens, the CNC supplier in Elk Grove Village, Illinois, no longer made a dedicated control for the grinder, a suitable CNC was selected from the current standard line of Siemens product.
The Sinumerik 810D CNC was chosen for the following reasons, as determined by Eaton and Ex-Cell-O engineers: * Compact design - drives and controls are in the same package, resulting in a considerable space savings.
* Digital axis drives - digital drives and absolute encoders minimized hardware and had definitive size advantages for the application.
* HMI interface - compact design of the CNC control interface kept the control console in the same package.
* Custom cycles - Siemens cycle programming eliminated some programming of grinding cycles.
* Imbedded PLC - powerful Siemens Step 7 imbedded PLC controller further enhanced the HMI protocol.
The original Heald grinder controls console required some redesign, as the Siemens Sinumerik 810D control panels are slightly wider than the original System 3.
However, the redesign was achieved, with the capability of mounting to the existing pendant support art on the machine.
The PLC interface was accomplished with Step 7 PLC logic with separate I/O Siemens hardware that provided a more compact design and easily interfaced with the existing I/O terminal connectors.
The Sinumerik 810D is a compact, PC-based control that is used for simple to medium-range CNC applications.
It features an integrated NC, PLC and is capable of handling up to six axes and two spindles.
SIMATIC PLC consists of standard hardware and software components that can be individually tailored to the task at hand.
It is the standard automation system for controlling the widest variety of machines and plants.
The existing program format was used to maintain the operator compatibility with the old programs.
The old programs were approximately 75% transportable with modifications implemented to those areas that required new functionality.
This minimized operator impact with new equipment since the operator controls and the program parameters were basically the same as the old equipment.
Special operator interface screens were designed to match the original parameter values, reducing the need for extensive training of the operator interface system.
Fault and Operator Messages were programmed to minimize downtime and give as much information as possible to the operator and maintenance personnel.
Eaton engineers Rick Gentry and Jim Guess have reported over 11% increases in the overall productivity of the Heald grinder, with the additional advantages of improved throughput and enhanced accuracy since the retrofit.
The retrofit project at Eaton required approximately six weeks to implement and obtain customer approval.
CNC retrofit raises gear grinder output, accuracy
In early 2005 CNC Design performed a retrofit on a Pfauter Kapp PE1000G gear grinder at David Brown Gear Industries' Woolongong plant. The heat treatment process used to harden gears and pinions distorts them slightly, so before being fitted to a gearbox these workpieces must be ground to eliminate this distortion. The Pfauter Kapp grinding machine, originally built in 1988 performs this critical final step in the production process.
However the hardware and software used on the machine was becoming obsolete and hard to maintain while the user interface was difficult to learn and inflexible.
The retrofit involved the installation of Siemens 1FT6 digital servo motors to all feed axes.
These motors are controlled by Simodrive 611D digital drives which allow the use of feedforward control.
This provides extremely stiff control and fast machine response which is evident in the smooth surface finish on the gear teeth being ground.
The existing spindle motor was retained and connected to a new 611U drive.
The drives are controlled by a Sinumerik 840D CNC.
This is the only product on the market offering integrated safety features.
Sinumerik Safety Integrated is now responsible for monitoring the working space and ensuring the safety of the operator during workpiece set-up and while checking results.
Safe Standstill monitoring, Safe Speeds and Safe External Stops are implemented to create maximum operator safety at all times.
A new user interface was developed in consultation with the machine operators to allow flexible and intuitive control of the grinding process.
The interface runs on a PCU50 control panel which allows grinding and setup data to be saved to the internal hard disk.
Not only did the upgrade provide an easy to understand and intuitive interface, it also allowed greater flexibility during the grinding process.
Any further machine upgrades or diagnosis are also made easier by incorporating a modem which allows secure remote access to the machine software.
The entire commissioning process, including the rewiring of the entire machine, the refurbishment of all ancillary systems, tuning of all axes and the testing of all grinding cycles, was performed in a six week period of down-time.
Full production was able to begin immediately after this commissioning period.
Reductions in grinding time of up to 40% have been experienced on the refurbished machine.
And importantly, operator interaction has been reduced, increasing efficiency and allowing the operators more time to perform other tasks.
Overall, both management and operators at the David Brown plant are extremely happy with the result of the project.
Not only have productivity and usability been improved, but the future viability of the Pfauter Kapp is assured at a fraction of the price of a new machine
However the hardware and software used on the machine was becoming obsolete and hard to maintain while the user interface was difficult to learn and inflexible.
The retrofit involved the installation of Siemens 1FT6 digital servo motors to all feed axes.
These motors are controlled by Simodrive 611D digital drives which allow the use of feedforward control.
This provides extremely stiff control and fast machine response which is evident in the smooth surface finish on the gear teeth being ground.
The existing spindle motor was retained and connected to a new 611U drive.
The drives are controlled by a Sinumerik 840D CNC.
This is the only product on the market offering integrated safety features.
Sinumerik Safety Integrated is now responsible for monitoring the working space and ensuring the safety of the operator during workpiece set-up and while checking results.
Safe Standstill monitoring, Safe Speeds and Safe External Stops are implemented to create maximum operator safety at all times.
A new user interface was developed in consultation with the machine operators to allow flexible and intuitive control of the grinding process.
The interface runs on a PCU50 control panel which allows grinding and setup data to be saved to the internal hard disk.
Not only did the upgrade provide an easy to understand and intuitive interface, it also allowed greater flexibility during the grinding process.
Any further machine upgrades or diagnosis are also made easier by incorporating a modem which allows secure remote access to the machine software.
The entire commissioning process, including the rewiring of the entire machine, the refurbishment of all ancillary systems, tuning of all axes and the testing of all grinding cycles, was performed in a six week period of down-time.
Full production was able to begin immediately after this commissioning period.
Reductions in grinding time of up to 40% have been experienced on the refurbished machine.
And importantly, operator interaction has been reduced, increasing efficiency and allowing the operators more time to perform other tasks.
Overall, both management and operators at the David Brown plant are extremely happy with the result of the project.
Not only have productivity and usability been improved, but the future viability of the Pfauter Kapp is assured at a fraction of the price of a new machine
CNC Retrofit Gives New Life to Old Mills
Stellex Monitor Aerospace Inc. (Amityville, NY) operates 10 Cincinnati Milacron gantry-style milling machines to produce titanium and aluminum alloy aerospace components. A CNC retrofit-completed on five units so far-has given the machines a new lease on life.
Originally equipped with Cincinnati’s Acramatic controls, the mills now have new digital servomotors, drives, and CNCs supplied by the Machine Tool business unit of Siemens (Elk Grove Village, IL). The Sinumerik 840D controls run on a Windows XP platform, and provide true 3-D five-axis cutter compensation and kinematic transformation.
According to VP Gary Kahrau, benefits from the retrofit include reduced setup time, improved part surface finishes, fewer secondary finishing operations, and significant improvement in overall productivity.
The oldest mills retrofitted were built in 1978. “They actually perform better now than when they were new, owing to the significant improvements in control technology,” Kahrau says. “The Sinumerik CNCs include several features for five-axis aerospace cutting simply not available from other control suppliers.”
One such feature of the open-architecture controls is real-time, five-axis kinematic transformation capability called TRAORI, which eliminates postprocessing and the potential loss of part geometry information. By directly accepting part data, the CNCs can reproduce smooth, accurate toolpaths and provide accurate 3-D cutter compensation.
When Stellex runs the same part on different machines, TRAORI compensates for the particular machine kinematics, minimizing the need for part programs for each machine configuration and providing flexibility to move production from one machine type to another. The controls can also accept program data from a post-processor, allowing Stellex to use previously developed programs if desired.
In addition to the CNC retrofit, Siemens also provided a dynamic machine engineering analysis called Mechatronics. The three-step process involves collecting real-time machine performance data, establishing optimized CNC and servodrive parameters, and verifying the resulting machine performance. Kahrau says the process cut rotary axis error on the five-axis gantry machines in half. Circle 224
http://www.cncmachinesinfo.com/articles/category/cnc-mill/
Originally equipped with Cincinnati’s Acramatic controls, the mills now have new digital servomotors, drives, and CNCs supplied by the Machine Tool business unit of Siemens (Elk Grove Village, IL). The Sinumerik 840D controls run on a Windows XP platform, and provide true 3-D five-axis cutter compensation and kinematic transformation.
According to VP Gary Kahrau, benefits from the retrofit include reduced setup time, improved part surface finishes, fewer secondary finishing operations, and significant improvement in overall productivity.
The oldest mills retrofitted were built in 1978. “They actually perform better now than when they were new, owing to the significant improvements in control technology,” Kahrau says. “The Sinumerik CNCs include several features for five-axis aerospace cutting simply not available from other control suppliers.”
One such feature of the open-architecture controls is real-time, five-axis kinematic transformation capability called TRAORI, which eliminates postprocessing and the potential loss of part geometry information. By directly accepting part data, the CNCs can reproduce smooth, accurate toolpaths and provide accurate 3-D cutter compensation.
When Stellex runs the same part on different machines, TRAORI compensates for the particular machine kinematics, minimizing the need for part programs for each machine configuration and providing flexibility to move production from one machine type to another. The controls can also accept program data from a post-processor, allowing Stellex to use previously developed programs if desired.
In addition to the CNC retrofit, Siemens also provided a dynamic machine engineering analysis called Mechatronics. The three-step process involves collecting real-time machine performance data, establishing optimized CNC and servodrive parameters, and verifying the resulting machine performance. Kahrau says the process cut rotary axis error on the five-axis gantry machines in half. Circle 224
http://www.cncmachinesinfo.com/articles/category/cnc-mill/
Control retrofit transforms grinding operations
A three-axis Anilam CNC control system more usually found controlling milling machines has transformed the capability of a rebuilt Jones and Shipman 540 toolroom surface grinder at tooling manufacturer, Electro-spark. The grinder, which before being rebuilt was a manual machine, has enabled the Cwmbran (South Wales) company to reduce cycle times and improve quality levels in the production of components which are now machined under full three-axis (x, y and z) control with the Anilam system. The machine has been completely rebuilt and fitted with DC drives on all three axes, with the drives being controlled by the Anilam MK 3300 CNC.
Also, the original 1.1 kW grinding wheel spindle drive motor has been replaced by a 3.7 kW motor which drives the spindle through a poly-vee belt.
As a result of the new drives and larger motor - and in combination with the fine degree of positional and rotational control provided by the Anilam CNC - the machine is now being used also for creep feed grinding.
The benefit of this is illustrated by Electro-spark managing director, Dave Calder, who quotes one of the first jobs carried out on the refurbished machine.
"The component was previously ground by multiple passes and small downfeed movements of the wheel", he says.
"With 50 ground in one setup, the production rate was then 350 parts an hour.
On the new machine, however, a 0.020in deep cut is used to enable the work to be completed in one pass and, as a result, throughput has risen to 600 an hour.
Component quality has improved too, because there is no longer the disturbance of the work by wheel contact at the beginning of each pass as with reciprocal grinding.
Also, because of the greater degree of control on feed rate and positioning, it is possible to fast feed the wheel close to the point of cutting before reducing to the creep feed rate.
This has also contributed to the improved cycle time".
While Electro-spark provides a subcontract tool making service, its primary role is making tooling components for one of its sister companies, Iron-spray, which manufactures tools in volume for use in carpet-making and weaving machines.
It cost Dave Calder GBP 22,000 to have the machine rebuilt and the CNC integrated.
The Anilam retrofitting, which included fitting new ballscrews and drives, was carried out by Machine Tool Control of Pontypool, South Wales - Anilam's representative in Wales and a specialist in CNC retrofitting with over 20 years experience in the sales and support of the Anilam product range.
"To buy a new CNC machine with a comparable CNC would have cost three times as much, and the machine would have been too big for the light precision work we now do on it", reckons Dave Calder.
"Due to its success there are now plans to have a second grinding machine rebuilt for control by a two-axis Anilam MK 3200 unit".
As well as being good value for money, the rebuild and retrofit has provided Electro-spark with a type of machine control well suited to its toolmakers' style of working.
"It is programmed logically in the way the machine operator thinks", continues Dave Calder.
"He simply tells the CNC what he thinks the machine needs to do.
He can have a picture of the operations in his mind, as if he were turning the handles.
Nor does making a single movement change to a program affect any other movements that are part of an operating cycle".
The grinder is permanently fitted with a fixturing system to which all subfixtures accurately locate; this facilitates the transfer of workpieces to milling and EDM machines.
The axial position of the main fixture on the grinder is precisely known so that its relationship to the grinding wheel can be accurately determined by the CNC.
"The operator brings the wheel to where the cutting will start and sets the zero position.
After that, all the movements can be programmed in sequence.
The average job takes about ten minutes and it is so logical.
All the programs we have so far created are stored in the CNC's ample memory".
The versatility of the retrofit machine and its new controller is illustrated by one example which involved grinding a group of identical parts as one setup.
When completed on a manual grinder the fixture had a small error in alignment so the height of the last piece differed from the first by 0.002in.
This was compensated for by grinding the middle part to size then the first and last on top and bottom limits.
"We put it on the new machine and programmed the Anilam to give a 0.002in fall along the length of the batch", says Dave Calder.
"When we checked them they were all parallel and in tolerance.
From then on the operator felt fully at home with the control; it is so user friendly.
I know we should have corrected the fixture in the first place, but now there is no need to".
In addition to tool steel, tungsten and exotic metals, the machine also grinds ceramics.
For holding these non-magnetic materials, Electro-spark has recently started using the Cryotech ice-chuck.
This system was developed in Switzerland and last year the product and name was purchased by Dave Calder to enable him to manufacture and market the novel workholding device.
The Cryotech ice chuck creates a holding force of 15kg/cm2, sufficient for machining by grinding and other methods.
With the workpiece placed on the wetted chuck surface, the water is frozen using microprocessor control and as it turns to ice it securely holds the workpiece.
The complexity of work now possible on the Jones and Shipman machine, and in this particular instance with the aid of the Cryotech ice chuck, is shown in its ability to grind a very thin plate that has a three-dimensional crowned surface.
This called for the 100mm square plate to be held firmly and to have its top surface crowned in both directions, using both longitudinal and transverse table movements to form part of the spherical surface.
All the wheel and table movements needed to achieve the shape were programmed sequentially into the Anilam CNC by the operator to create the precise form.
http://www.engineeringtalk.com/news/ani/ani110.html
Also, the original 1.1 kW grinding wheel spindle drive motor has been replaced by a 3.7 kW motor which drives the spindle through a poly-vee belt.
As a result of the new drives and larger motor - and in combination with the fine degree of positional and rotational control provided by the Anilam CNC - the machine is now being used also for creep feed grinding.
The benefit of this is illustrated by Electro-spark managing director, Dave Calder, who quotes one of the first jobs carried out on the refurbished machine.
"The component was previously ground by multiple passes and small downfeed movements of the wheel", he says.
"With 50 ground in one setup, the production rate was then 350 parts an hour.
On the new machine, however, a 0.020in deep cut is used to enable the work to be completed in one pass and, as a result, throughput has risen to 600 an hour.
Component quality has improved too, because there is no longer the disturbance of the work by wheel contact at the beginning of each pass as with reciprocal grinding.
Also, because of the greater degree of control on feed rate and positioning, it is possible to fast feed the wheel close to the point of cutting before reducing to the creep feed rate.
This has also contributed to the improved cycle time".
While Electro-spark provides a subcontract tool making service, its primary role is making tooling components for one of its sister companies, Iron-spray, which manufactures tools in volume for use in carpet-making and weaving machines.
It cost Dave Calder GBP 22,000 to have the machine rebuilt and the CNC integrated.
The Anilam retrofitting, which included fitting new ballscrews and drives, was carried out by Machine Tool Control of Pontypool, South Wales - Anilam's representative in Wales and a specialist in CNC retrofitting with over 20 years experience in the sales and support of the Anilam product range.
"To buy a new CNC machine with a comparable CNC would have cost three times as much, and the machine would have been too big for the light precision work we now do on it", reckons Dave Calder.
"Due to its success there are now plans to have a second grinding machine rebuilt for control by a two-axis Anilam MK 3200 unit".
As well as being good value for money, the rebuild and retrofit has provided Electro-spark with a type of machine control well suited to its toolmakers' style of working.
"It is programmed logically in the way the machine operator thinks", continues Dave Calder.
"He simply tells the CNC what he thinks the machine needs to do.
He can have a picture of the operations in his mind, as if he were turning the handles.
Nor does making a single movement change to a program affect any other movements that are part of an operating cycle".
The grinder is permanently fitted with a fixturing system to which all subfixtures accurately locate; this facilitates the transfer of workpieces to milling and EDM machines.
The axial position of the main fixture on the grinder is precisely known so that its relationship to the grinding wheel can be accurately determined by the CNC.
"The operator brings the wheel to where the cutting will start and sets the zero position.
After that, all the movements can be programmed in sequence.
The average job takes about ten minutes and it is so logical.
All the programs we have so far created are stored in the CNC's ample memory".
The versatility of the retrofit machine and its new controller is illustrated by one example which involved grinding a group of identical parts as one setup.
When completed on a manual grinder the fixture had a small error in alignment so the height of the last piece differed from the first by 0.002in.
This was compensated for by grinding the middle part to size then the first and last on top and bottom limits.
"We put it on the new machine and programmed the Anilam to give a 0.002in fall along the length of the batch", says Dave Calder.
"When we checked them they were all parallel and in tolerance.
From then on the operator felt fully at home with the control; it is so user friendly.
I know we should have corrected the fixture in the first place, but now there is no need to".
In addition to tool steel, tungsten and exotic metals, the machine also grinds ceramics.
For holding these non-magnetic materials, Electro-spark has recently started using the Cryotech ice-chuck.
This system was developed in Switzerland and last year the product and name was purchased by Dave Calder to enable him to manufacture and market the novel workholding device.
The Cryotech ice chuck creates a holding force of 15kg/cm2, sufficient for machining by grinding and other methods.
With the workpiece placed on the wetted chuck surface, the water is frozen using microprocessor control and as it turns to ice it securely holds the workpiece.
The complexity of work now possible on the Jones and Shipman machine, and in this particular instance with the aid of the Cryotech ice chuck, is shown in its ability to grind a very thin plate that has a three-dimensional crowned surface.
This called for the 100mm square plate to be held firmly and to have its top surface crowned in both directions, using both longitudinal and transverse table movements to form part of the spherical surface.
All the wheel and table movements needed to achieve the shape were programmed sequentially into the Anilam CNC by the operator to create the precise form.
http://www.engineeringtalk.com/news/ani/ani110.html
A look at the different options for upgrading an old machine tool
Anyone considering the purchase of a new machine tool at IMTS will probably wonder if his current machine could be upgraded. This article explores the three primary types of machine tool upgrades available from builders and third-party specialists: retrofit, rebuild and remanufacture.
Going Retro
The term “retrofit” usually means an upgrade to just the CNC. However, a control upgrade should also include new servomotors, drives, magnetics (motor starters, breakers, solid-state relays, etc.) and a complete rewiring of the machine.
A retrofit costs about 30 percent of the price of a new machine, so the retro candidate must be mechanically sound to justify the investment. The OEM, or reputable third-party rebuilder, can provide a complete mechanical assessment of your machine tool.
Don’t be afraid to pay for a second opinion. It often proves to be money well spent.
An older CNC machine tool undergoing a retrofit probably will have a control installed that incorporates features not available at the time the machine was purchased. Faster data-processing speed means a faster acceleration/deceleration rate and axis motion, and greater positioning accuracy.
These capabilities are what make it wise to upgrade a machine’s servomotors, drives and magnetics during a retrofit. Failing to upgrade the entire system means the user won’t realize the full benefits of his new CNC.
Many older controls have no host-computer communication capabilities, while new CNCs provide a variety of communication options. Today’s controls also have built-in computer diagnostics to assist the operator, programmer and maintenance person when troubleshooting a tooling problem, programming error or machine fault.
A dedicated control just runs the machine tool, while a PC-based CNC can run the machine program and other software simultaneously. Both types have advantages. Familiarize yourself with what each offers in terms of speed, programming features and memory before selecting your new control.
Servos, Drives, Wiring
The predominant servomotor installed on new and upgraded machine tools is the brushless AC motor. It has an excellent power-to-size ratio and requires little or no maintenance. Some dedicated controls mandate the use of both digital servomotors and drives—an excellent combination—in order to upgrade the control.
The drive tuning on a digital system is done via the control screen, with soft parameters; no manual tuning is required. The connections between the drive and CNC are usually serial or fiber optic, a faster and more reliable method than analog connections. Some control and drive manufacturers have joined forces in an effort to develop digital interfaces that can be used with PC-based systems.
Although many successful retrofits are done without replacing the original magnetics system (motor starter, fuses, disconnect, relays, etc.), it’s not recommended. One of the advantages of having a new control, servomotors and drives is that they are significantly smaller than their earlier-generation counterparts. Similarly, the newer magnetics panels are smaller, so they occupy less floor space while meeting modern electrical codes.
Completely replacing the machine wiring also is a highly recommended. Rewiring also ensures that the machine meets modern electrical codes.
Today’s demand for higher spindle speeds raises the issue of whether to replace the spindle motor and drive. The limiting factor for increasing spindle speed is mechanical. You simply cannot put a 6,000-rpm motor in place of an 1,800-rpm motor without causing irreparable damage to the transmission.
But unlike servomotors, there are certain instances where it makes sense (as in dollars and cents) to rebuild the original DC motor and match it to a new digital DC drive. Generally, you should keep a DC system that’s above 30 hp and replace one that’s below 30 hp with a brushless AC system.
Make sure, though, that you consider the base motor speed. Older DC spindle motors have base speeds that range from 500 to 850 rpm, with top speeds of 2,500 to 3,000 rpm. The base speed of a brushless AC motor is usually 1,500 rpm, with maximum speeds as high as 10,000 rpm. If the base speed of the AC motor is three times the old DC motor, then at the original base speed, an AC motor will only generate one-third of the old DC motor’s rated horsepower.
One way around this problem is to change the gear or pulley ratio. But if the motor is directly coupled to the spindle, some engineering work will be needed to make the brushless AC system generate the same low-speed horsepower.
A Rebuilding Season
When the machine tool industry refers to a rebuild, it generally means that all of the mechanical components of the machine are cleaned, inspected and then reassembled using new or remachined components. As with a retrofit, a rebuilt CNC machine costs about one-third the price of a new unit.
Good candidates for a rebuild are machines less than 12 years old that have a reliable CNC, and servomotors, a spindle motor and drives that do not need upgrading. Also, make sure that any unreplaced components are readily available and will continue to be supported for the expected life of the rebuild. Few things are more frustrating than to spend money on a rebuild only to discover later that the spindle-drive manufacturer, for example, no longer produces your machine’s drive.
Any major mechanical upgrade to a machine tool should always include the replacement of all bearings and seals, to OEM specifications.
In addition, the spindle assembly (or cartridge) and/or headstock should be completely disassembled and inspected. All internal bearings should be replaced, including the precision-class spindle bearings. All gears should be checked for wear and cracks. The shafts should be checked for straightness and all of the bearing journals should be repaired as needed. The spindle itself should be reground.
On a milling machine, the spindle taper and face must be reground to OEM specifications. The drawbar should be rebuilt, which includes replacing all of the clamping springs. Lathe spindles should be checked for straightness. The taper must be carefully inspected and, if necessary, reground. The final reassembly should follow the OEM specification for proper runout and endplay.
It’s possible that damage to the spindle/headstock will be too severe to repair, but that cannot be known until it is taken apart and inspected. Fortunately, many of today’s OEMs manufacture and stock replacement spindle assemblies and cartridges.
Another mechanical area to be rebuilt is the way system. The work done here is critical to returning the machine to its original accuracy. The two primary systems used in the machine tool industry are box ways and linear guides.
If your machine has box ways, they should be visually inspected for scoring and checked for hardness. Most new ways have an average hardness of Rc 50 to 63 at a depth of 0.090" to 0.125". They should be reground flat, perpendicular and parallel, within 0.0002" TIR and a 32µin. finish. This level of accuracy is obtained by grinding the ways on a precision bed grinder. The ways should have no less than a 0.050" depth of hardness after grinding to ensure longevity. If a way has scoring below that depth of hardness, it may have to be scrapped. If the way is integral to the casting, it can sometimes be repaired, but this is not prudent.
Some OEMs make their ways removable. While removable ways can be finish-ground off the machine, they should be reinstalled and then ground in place to ensure the highest possible accuracy.
Hardened-steel box ways incorporate one of three common slide techniques. The first, and most economical, involves the use of a low-friction material like Turcite or Multifil. The existing material is removed from the slide. Then new material is glued in place and the slide is hand-scraped and fitted to the ways.
An alternate technique is to machine the base of the slide to accept a “wear strip.” Then Turcite or Multifil is glued to a piece of spring steel so that it can be removed for fitting. Future replacement of the wear strip is easier because the slide does not need to be removed.
The second type of slide system incorporates linear roller bearings. The roller bearings are placed side by side in a cage that resembles a tank track. The cage is held together with a rubber banding and rides in pockets milled in the slides. The rebuilder should replace these bearings.
If the box ways are made of cast iron rather than steel, they can be reworked by two common methods. One is hand scraping and mating the way to the slide until it reaches the accuracy of the OEM specification. But there are at least three potential downsides to this approach.
One is the machine tool’s feed rate. This metal-to-metal slide method cannot be driven at rapid feed rates much over 200 ipm. Second, this way system is prone to damage from contamination, usually in the form of metal chips that get between the slide and way, causing scoring that severely reduces machine accuracy. Third, the hand scraping of ways is a rapidly disappearing art. If a company offers this service, check customer references for machines that are at least a year beyond their warranty period. You need to be absolutely sure that the company you contract to rebuild your machine knows what it’s doing with respect to scraping ways.
The second method of reworking cast iron box ways is to grind the way to allow Turcite or Multifil to be fitted to the slide. Today’s precision grinders produce highly reliable results and attain excellent surface finishes that meet the OEM specification.
A third type of slide, which is found on larger machines, is the hydrostatic system. With this design, the slide rides on a film of oil at all times. When rebuilding a hydrostatic system, all of the pressure-compensating valves must be replaced. The slide should be checked for a proper fit to the way system and scraped as necessary.
The majority of modern CNC machine tools use linear guides. A linear guide system consists of a pair of rails. On each rail rides two or more bearing packs that are called “trucks,” which attach to the table or column. If they are still in good condition, they can be reused after basic maintenance is performed.
Unlike box ways, linear guides cannot be reground. Linear guide rails and trucks wear as a system. If replacement is needed, insist that both the rails and trucks are replaced.
Ballscrews are the heart of your axis accuracy and can be expensive to replace. But fortunately, most ballscrews can be rebuilt once—sometimes even twice—depending on the amount of wear or damage that must be corrected. This service is generally outsourced by rebuilders to shops that specialize in the manufacture and remanufacture of ballscrews.
The process requires the screw and nut to be disassembled and inspected for hardness, rust and wear. It then can be determined if a repair is possible. A reground ballscrew will be returned with a new nut, while the bearing journals are checked and repaired as necessary. The ballscrew is then reinstalled with new thrust bearings and checked for accuracy to ensure proper height, parallelism and runout.
If a repair is impossible, be aware that new ballscrews can have a lead time of eight to 10 weeks. Remanufactured screws are usually out and back in less than a month.
Checking Fluids
A machine’s hydraulic fluid reservoir should be thoroughly cleaned during any rebuild. The pump and motor should either be rebuilt or replaced, along with any filters or strainers. The flexible hydraulic hoses must also be replaced.
The solenoid valves of a hydraulic system normally do not fail mechanically; a burned-out coil is the usual culprit. Therefore, the decision to replace them during a rebuild is usually made by assessing the risk of obsolescence and whether the valves have been prone to frequent failure in the past.
The central lubrication system is the single most important system on any CNC machine. All of the flexible lube lines must be replaced and all of the metal lines flushed and tested for leaks. The pump should always be replaced.
There are types two of central lube systems on a CNC machine. The one-line resistance system consists of a low-pressure pump that sends a single line of lubricant directly into a manifold. The multiple lines that exit the manifold are routed to individual lubrication points throughout the machine tool. A “metering unit” in each line serves to regulate the rate of oil flow.
A small orifice in the metering unit supplies the proper amount of oil for a given lubrication point. The units come in various sizes, based on the amount of oil that is needed. All metering units must be replaced.
The second lube system is the progressive type, which uses a high-pressure (up to 3,000 psi), air-over-oil pump with individual feeder blocks that contain “spools.” Each time the pump piston fires, these spools are shifted in the blocks, precisely controlling the amount of oil that reaches each lubrication point. A block can sense if a spool has not shifted, sending a lubrication alarm to the CNC.
A progressive system can be completely flushed, inspected and reused. If your machine tool cuts cast iron or other abrasive materials and is equipped with a one-line system, consider converting to a progressive-type system.
Final Approach
Reassembly of a machine being rebuilt begins at the base, with proper leveling. A weight shift occurs as each major component (table, spindle, column, etc.) is added to the base. The risk of accuracy error is significantly reduced when the level is rechecked after each major component is added to the machine base. Geometric alignments should be made using OEM procedures and tolerances.
Proper alignment includes a static check performed with a granite square and electronic levels. By today’s standards, proper alignment also includes a dynamic check with a system that provides a computer-generated analysis of the accuracy of the machine tool in motion. A “ballbar” test ensures that the individual axes are aligned correctly and that the relationships between the axes in motion are also accurate.
Rebirth
The most comprehensive type of machine upgrade is remanufacturing. It combines everything involved in a retrofit and rebuild. Plus, a remanufacture job includes design changes that improve the machine’s performance beyond its original specifications.
These changes could include an increase in the rapid and cutting feed rates, extended axis travels and a higher spindle speed.
At half the cost of a comparably equipped new machine, remanufacturing is only practical when a new replacement machine would cost $400,000 or more.
A typical retrofit that includes a control, servomotors and drives will take four to eight weeks. Most control manufacturers have delivery schedules in the four-to-six-week range, so a control-only retrofit is slightly faster.
The delivery for a complete rebuild should range between 12 and 16 weeks, depending on the extent of the damage and wear to the machine tool. A remanufacture will take five to seven months from the time the machine leaves and returns to your shop floor.
Get It In Writing
Machine tool documentation is a critical element of any machine tool upgrade. The lack of accurate and complete documentation can turn an otherwise good retrofit, rebuild or remanufacture into a disaster when the first problem crops up.
At a minimum, documentation should include high-voltage schematics, all of the input and output diagrams, a complete servo/spindle wiring schematic (including all pin-outs on the plugs), physical machine-view drawings and an operator’s manual.
The last piece of documentation may be controversial, so spell it out in the contract. No machine upgrade is complete without a fully cross-referenced ladder or soft-logic diagram. Some OEMs and third-party specialists believe that this is their proprietary information. But you cannot effectively troubleshoot a CNC machine without it.
All of the documentation should be provided in several formats. Insist on a hard copy with a digital backup written in a commonly available format that can be stored, duplicated or reprinted in-house.
Interview the operators and maintenance mechanics to expose any known problems with machine performance before any work is contracted. In the written agreement, spell out the specific performance problems you expect to be eliminated by whatever upgrade is selected.
Competent firms will give you a list of references and offer to show you machines they have upgraded.
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