Industry experts highlight significant role for EDM
Industry experts highlight significant role for EDM
Keywords Aerospace,AGIE, EDM
AGIE Ltd's first ever Aerospace Day at its Coleshill premises gave manufacturers the opportunity to hear from industry experts, including Rolls-Royce and Lucas Aerospace, on the competitive advantage to be gained through AGIE EDM.
A series of seminars throughout the day aimed to deepen awareness of EDM capability and to dispel any misconceptions of a mysterious "black art".
"The Aerospace '98 Open Day is part of AGIE's campaign to increase knowledge levels about EDM as a production process", said Glynn Fletcher, managing Director of AGIE Ltd. "The aerospace industry, as a leading edge sector where quality is crucial, is ideally suited to EDM. We have called on leading companies, including first tier manufacturers and subcontractors, which are already using AGIE EDM, to create an interesting and educative programme to present the full spectrum of EDM potential."
Speaking on the possibilities for EDM within production applications was Hans-Peter Gruber,manager of Special Machines Division for AGIE Industrial Electronics Ltd,Switzerland. Case histories illustrated AGIE's problem-solving approach and the customisation of installations to meet specific customer requirements. Issues covered included compatibility, automation, and 24-hour production. The subject of this presentation was further illustrated by Ian Wilson, project manager for Lucas Aerospace, which AGIE has recently helped to integrate EDM into a new single flow manufacturing system at its Shaftmoor Lane site in Birmingham.
The single flow method, in which AGIE machines play a crucial role, will help Lucas Aerospace achieve smaller batch production, reduce stock levels and greatly improve throughput times.
Lucas Aerospace is a leading global supplier of aircraft components for major names in the aerospace industry with UK sites in Birmingham, Hemel Hempstead, Wolverhampton and Liverpool. A specially dedicated project team at Lucas Aerospace has spent six months planning cells for one-piece material flow at the Shaftmoor Lane manufacturing facility in Birmingham. Five cells are planned, each representing an investment of £1 million, with the first due to be up and running in October 1998 and the others scheduled for completion in January 1999. The cell introduction is part of a major reorganisation of the plant to create a centre for excellence, concentrating on valve manufacture.
A 20-strong project team at Lucas Aerospace has been involved in the planning of the cells and has identified part groups and specific machining routes for individual components. The first U-shaped manufacturing cell, which is based on the Toyota production system, works on 90 different components, with an operator moving each part around the machines, completing one stage before progressing to the next.
Lucas Aerospace has invested in an AGIE Classic wirecut and Innovation diesink for the machining of difficult profiles on stainless steel valve sleeves for fuel metering and pump units. The EDMs form a branch line down the middle of two cells together with an optical measuring machine and lapping and cleaning stations. Components are moved to the branch line once they have passed through the necessary machining stages in one of the two main cells which comprise CNC turning machines, a CNC milling machine, a drilling station, deburring stations, and honing.
The valves produced are used in a wide range of aerospace applications including Rolls-Royce's new Trent engine, the EFA Typhoon, the Airbus A310, A319, A320 and A340 and the Pegasus engine for the Harrier Jump Jet. The profiles eroded by the AGIE machines require a tolerance of ± 10 microns and, because of their small dimensions and position on the curved side surface of the valves, would be difficult to machine using a method other than EDM.
Lucas Aerospace calculated a typical takt time of 15 minutes for the main cells, derived by dividing the 4,000 machining hours available each year by the 16,000 parts each cell has to produce. This means that every 15 minutes a valve needs to be completed on the main cells ready to pass to the AGIE machines for erosion of the profiles. In order to avoid a bottleneck at the erosion stage, Lucas Aerospace has divorced the EDM process by creating a branch line which relies on the Classic and Innovation to guarantee a low cycle time of about one hour. With this cycle time, the AGIE machines help Lucas Aerospace to maintain the pace of production,while still achieving the very tight tolerances and repeatability it requires. Repeatability is particularly important as single flow emphasises the need for consistent, guaranteed quality.
The single flow manufacturing system has many benefits for Lucas Aerospace. Whereas before each machine required a dedicated operator, now each operator works multiple operations, overseeing one machining operation before moving the workpiece to the next stage. As parts are not stockpiled at any one machine, considerable time and therefore cost savings are made and lead-times have been remarkably improved, in some cases from eight weeks to just one. In addition, all machines within the cell are programmed centrally resulting in greatly reduced programming times. Stock levels are also kept to a minimum as a part is fully completed on the cell, boxed and ready for the customer.
"The structure of the new cell has significant time and financial savings for us and whichever EDM we chose needed to be able to help us maximise these benefits", said Malcolm Perks,module engineer for Lucas Aerospace, Shaftmoor Lane. "We chose AGIE machines to be a part of the system because they are the best in terms of performance,price, support and supply of spares. Should we need them in the future, AGIE are able to supply us with spares very quickly and in case of technical problems they can have an application engineer out to provide advice within 24 hours."
Colin Radnedge, one of the UK's leading experts on aerospace applications, with 28 years' experience in Manufacturing Technology at Rolls-Royce plc's Aerospace Division, gave an insight into the company's selection of EDM. "It would be harder to obtain the same quality of surface finish on our materials using lasers than it is with EDM", he said. He highlighted whathe sees as an increasingly significant role for the process in the future of aerospace manufacturing.
Completing the programme was a presentation by David Light, managing director of EDM subcontractors and AGIE customer, Di-Spark. The talk covered persistent misconceptions about EDM focusing on the company's recent survey of awareness among UK manufacturers which revealed that 65 per cent still do not know the tolerances that can be achieved.
Further details from AGIE Ltd. Tel: +44 (0) 1675 463112.
