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.’

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