Polishing wheels meet aerospace industry demands

Paul Boughton
From its 1,875 m2 former Victorian lace mill in Sandiacre, Nottingham, C&H Precision Finishers provides ongoing support to many aerospace and aero engine manufacturing companies, as well as a diverse range of industry sectors that call upon it polishing and finishing expertise as an ad hoc subcontract service.

For aero engine customers the majority of the work involves cleaning up the forged or cast blades, smoothing out or taking off any defects that may create process problems further down the line, such as a second press operation that would result in defects being pressed back into the blade.

General Manager, Jack Oldershaw, says: “Over 90 per cent of the 60 people employed are hands-on production staff. Experience is one of the most important things, and everyone on the shopfloor will tell you that. We have trainees here with just 12 months experience, but they are being mentored by polishers with 20 to 25 years under their belts. That’s the key to our success, the staff we have here are very dedicated.”

C&H Precision Finishers is part of a global group, Avingtrans, with diverse high-tech sister engineering companies in the UK, China, America and Germany. Aerospace customers work includes A320 and A340 landing gear for Messier-Dowty, cast and forged engine components for Mettis Aerospace and, of course, Rolls-Royce.[Page Break]

“To the uninitiated this seems like a simple job, but we conduct full 100 per cent inspection because there are three elements that matter to us as a business; quality, lead time and cost. If these three key points aren’t right then our competitors will have an opportunity to step in, so we know it is crucial that every facet is addressed. Achieving all three is supported by the advanced finishing solutions provided by Meister Abrasives,” explains Quality Manager, Dave Sammans.

There are internal aerospace standard quality systems and also process-specific quality checks for some components, while most aerospace customers define the polishing process required for blades and other components in very fine detail.

Dave Sammans continues: “Some customers developed a controlled polishing process and know exactly what they require; they want a specific wheel as it provides the ideal cost-to-performance ratio. However, with polishing it has to be applied correctly as there are so many things that can go wrong and, just like that, you are starting over again.” [Page Break]
For its blade sets Rolls-Royce specified Meister Abrasives’ GP plus and 632/ 732 polishing wheels, and a stock of the wheels are held to meet the customer’s production schedule. This is important as many aerospace customers keep delivery records to ensure the supply chain is performing as expected and C&H Precision Finishers has a Silver Standard on time delivery performance of 97 per cent.
Ensuring such high delivery performance levels requires a close working partnership with suppliers such as Meister Abrasives that have extensive product and application knowledge. [Page Break]

Technical Sales Engineer, Damian de Souza, says: “Just like any other machining operation, selecting the correct parameters when polishing and finishing are vital to an efficient and productive operation. There are many variables to be considered, but fortunately at Meister Abrasives we have experienced a wide breadth of industry requirements and we can apply that knowledge to customer-specific issues.”

As well as aerospace customers leading manufacturers from other industry sectors rely on the company’s skills and expertise.

“We also get work in from automotive customers and general precision engineering companies. For these customers we have to quickly ascertain the level and standard of finishing required, as the parts are often required on a tight lead time. It is like that as a subcontract service, hand-to-mouth and you don’t get much warning, just a phone call that says ‘the parts on a truck coming to you now, and we need them back by yesterday’. Although we don’t have the luxury of a forecast or schedule for this work the same level of care and attention to detail is applied, and the fact that Meister Abrasives hold such an extensive stock of grinding and polishing wheels, as well as mounted points, becomes critical to our ability to turn work around quickly,” Jack Oldershaw states.[Page Break]

These sporadic customers send parts in and they are booked onto the company’s scheduling system before going on to the shopfloor where the supervisor distributes them to the appropriate work section. After the polishing and/or finishing is completed the parts are collected, inspected and sent back to the customer.

For more information, visit www.meister-abrasives.ch

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