AgustaWestlands Wildcat Supplier Tods Aerospace Ltd Specialises In Advanced Materials Technology

To help win and maintain this preferred supplier status to one of the world’s top aerospace manufacturing companies, Tods invested in a CMS five-axis router, a Renishaw RMP600 wireless touch probe and OMV Pro measurement software.

Yeovil, Somerset, UK, is home to world-leading aerospace manufacturer, AgustaWestland. The Anglo-Italian company employs nearly 4000 people in the area, plus countless others who work for its many suppliers. One of those suppliers is Tods Aerospace Ltd: a precision engineering business with a roster of 150 and an £18 million/year turnover.

Located at Crewkerne, Tods Aerospace is certificated as an AgustaWestland Silver Supplier, which marks it out as one of the best in its field. This privately owned company, which owns two factories on the Crewkerne industrial estate, ships finished parts directly to AgustaWestland’s production line. In other words, AgustaWestland trusts Tods Aerospace sufficiently that all its deliveries go directly, without goods-inward inspection, to production lines where some of the world’s most expensive and sophisticated military aircraft are built.

One of the largest AgustaWestland projects that Tods Aerospace has supported in recent years is the AW159 Lynx Wildcat: the next generation of Lynx helicopter being supplied to the UK Navy and Army. The UK Government awarded the £1billion contract in the summer of 2006 and in recent years Tods has been involved in the co-design and manufacture of several, major component parts for the aircraft, including the cockpit doors, the cargo doors and many of the main fuselage panels, all of which are made from carbon composite.

Controlling lead times and quality

‘Three years ago we invested in a 5-axis CMS router so we could make the tooling for these composite parts and other components in our own factory,’ says Tods Aerospace Operations Director, Richard Winterbottom. ‘Around the same time we were also bidding for increasingly complex 5-axis work. Our strategy is to bring more and more manufacturing capability in-house, so we can be more agile and keep better control of lead times and quality. This is particularly important during the early phases of new projects.’

A year later the company employed CNC Manager Bob Young, initially as CNC Programmer. ‘Prior to that, we were only using the machine’s basic capabilities,’ says Mr. Winterbottom. Bob Young had been with the company a year when manufacturing put together a proposal for a Renishaw RMP600 wireless touch probe and OMV Pro software.

The RMP600 is a compact touch probe which incorporates Renishaw’s patented RENGAGE™ high accuracy strain gauge technology and uses proven frequency hopping spread spectrum (FHSS) radio signal transmission. It offers all the usual benefits of Renishaw touch probes, including the ability to measure complex 3D part geometries on all sizes of machining centres.

‘One of the key reasons for purchasing the probe was to align the AW159 cabin roof and then machine it,’ says Mr. Young. ‘This has proven very successful and we are now producing our own CMM reports generated from the use of the Renishaw OMV software and the RMP600 probe. Without the probe we would not have been able to machine the roof as accurately and we couldn’t have aligned the jigs with such precision.’

Tods now supplies a total of 126 components for the AW159: One set (aircraft) per month.

‘We also use the Renishaw probe for first article inspection (FAI) on every new civil aircraft flooring project,’ adds Mr. Young. ‘For example, we currently have a project where a batch of machined components need to go back on the CMS router, as the customer has made a modification. We’ll use the probe to re-align the component prior to machining the additional feature.’

Reduction in scrap parts

Bob Young also claims that the RMP600 allows the company to take on more complex work and produce parts at the required high quality, faster than ever before. ‘We still feel that we’re in the early stages of getting to know the probe’s capabilities,’ he says, ‘but we are very happy with the accuracy and, in particular, the consequent reduction in scrap parts further down the production line. These are large, expensive components and we can use the probe to identify and avoid errors while we are still at the R&D stage.’

The accuracy gains attributable to the RMP600 touch probe are echoed by Tods’ Quality Director Martin Perks, who states, ‘Digital manufacture & digital design has given different sorts of tolerances and different features which using traditional measuring equipment such as micrometers and vernier calipers doesn’t really get us to the levels of quality and accuracy and checking that we require.’

Although Tods Aerospace is not the design authority, it does contribute significantly to the development of AW159 parts. The customer sends the company the space envelope for a CAD model, along with the design specification. ‘Our objective,’ says Mr. Young, ‘is usually to make a more simple assembly from fewer parts, to give better longevity, easier maintenance and overall, lower lifetime cost.’ The company aims to provide a better overall solution.

‘When we get a CAD model we take a close look and start working out a plan to machine the tooling. Once we have the first finished part, we’ll write a programme for the Renishaw probe, to check that all of the holes and features meet the specified tolerances.’

According to Richard Winterbottom, the company was the first local supplier to win AgustaWestland Bronze Supplier recognition, which was followed 18-months later by the silver award. ‘I think I’m right in saying that only 10 or so companies are permitted to supply AgustaWestland directly to stock’, says Mr. Winterbottom. Of course, no company gets an AgustaWestland Silver Supplier Award without the in-house capability to ensure that everything it delivers is exactly to specification.

Manufacturing investment to produce high-end parts

Tods Aerospace doesn’t try to compete against companies and countries making high-quantities of what Richard Winterbottom calls ‘steady-state’ products. ‘We are providing high-end parts where we work closely with the OEM during the development phase. We’ve invested heavily in our manufacturing capabilities to achieve the very highest quality, and that investment strategy is paying off.’

To get the most from any new technology, those who are charged with operating it must know exactly what it’s capable of. Both Bob Young and Richard Winterbottom agree that the reason Tods Aerospace invested in the Renishaw equipment owed a great deal to the level of support from the British company.

‘The Renishaw team has been fantastic,’ says Mr. Young, ‘especially with regards set-up and training. Their engineers spent hours with us, making sure we knew what we were doing. We looked at other suppliers, but we weren’t convinced they could support us as well as Renishaw could.’