Cost of manufacturing aerofoil gauging slashed

Aircraft Engineering and Aerospace Technology

ISSN: 0002-2667

Article publication date: 1 April 2000




(2000), "Cost of manufacturing aerofoil gauging slashed", Aircraft Engineering and Aerospace Technology, Vol. 72 No. 2.



Emerald Group Publishing Limited

Copyright © 2000, MCB UP Limited

Cost of manufacturing aerofoil gauging slashed

Cost of manufacturing aerofoil gauging slashed

Keywords: Walker Precision Engineering, Jones & Shipman, Grinding

Walker Precision Engineering of Cambuslang, Glasgow, reports that it is able to cut the cost of manufacturing aerofoil fixtures and gauges by up to 30 per cent because of the cost-effectiveness and productivity of a recently installed Jones & Shipman Dominator 624 Production Grinder. This cost saving is passed directly on, enabling Walker Precision to offer better terms to existing and new customers, thereby attracting an ever larger customer-base.

The Dominator is believed to be a new concept involving a total rethink of the surface grinding process. Incorporating a reciprocating wheelhead rather than the traditional reciprocating table design, major advances have been achieved in respect of structural rigidity, machine dynamics and smaller machine envelope. Selected by Walker's at the Scottish Manufacturing & Engineering Show in autumn 1998 and delivered in March this year, the Dominator forms an important part of the company's precision grinding resource.

By purchasing the Dominator, Walker's managing director Ian Walker saw an opportunity to slash the cost of manufacturing fixtures and fittings for the aerospace industry, a growth area for the company and one in which it operates a "total design and manufacturing solution" for its blue-chip client-base:

The introduction of this machine has allowed us access to a technically advanced, precision production grinder, the type of acquisition which, pre-Dominator, would just not have been economically viable. The Dominator allows us to plunge grind some fixture designs from a solid block with improved accuracy and surface finish, and naturally, reduced cycle times. These improved levels of accuracy and surface finish also allow us to grind pre-production blade samples on the new fixtures, eliminating the need for costly tooling trials by the customer.

Ian Walker sums up:

The Dominator was certainly the machine which most closely matched our application needs. Most important of all, it was affordable, with payback in about three years.

The purchase of such an innovative machine as the Dominator dovetails well with the technologically advanced culture which permeates through this thriving company. Formed in 1979, Walker Precision Engineering moved to its state-of-the-art facilities at Cambuslang Investment Park in 1996.

Ian Walker's formula of focusing on design and whole-project management for a smaller number of clients, rather than servicing the mass sub-contract market, has been very successful, the company trebling its turnover in three years and achieving in excess of £10 million turnover this year.

Although keen to encourage the recruitment of graduates, Walker Precision has not forgotten the role of the time-served engineer, with over 40 per cent of its current 130-strong workforce trained in-house through the company's Apprentice Training Programme.

Young engineer Steven Daly is one such apprentice-trained employee and the regular Dominator operator. He has quickly assimilated the programming format of the grinder - thanks to training delivered by Jones & Shipman and the ease-of-use of the Dominator's GE Fanuc Intelligent Terminal, which is programmed by a Jones & Shipman developed Windows ™ based software package.

A full suite of dressing and grinding programs is available to the operator. Easy to follow Windows ™ set up pages allow the operator to quickly digitise diamond and wheel positions and by a minimum of mouse or keyboard inputs produce a finished program. Graphical images prompt the operator and spreadsheet style programming ensures quick and simple input. The option of ISO programming is also available if required.

Grinding cell foreman Hugh Hainey is very enthusiastic about his new acquisition:

I am very impressed with the Jones & Shipman Dominator, though application-wise we have only touched the tip of the iceberg.

Our main application for the Dominator, so far, is the manufacture and overhaul of aerofoil receiver gauges for the aero-engine industry. These were notoriously difficult to manufacture due to problems with workholding, in combination with the need to achieve very close tolerances (2 microns) and high levels of surface finish (4m inch), which were necessary on the two large radii of the gauge.

Before the Dominator, we had to conventional and radial mill the gauge block, following which the radii were finished using a vertical wheelhead attachment fitted to a surface grinder. The radii were ground by manually rotating the work-piece about the fixed wheelhead using a radial plate, the radius of which was built-up using slips. The operation was time-consuming and accuracy was inconsistent. After virtually every pass, each radius had to be dimensionally checked using CMM equipment and corrections made to the set-up.

Using the Dominator for this application, there is no requirement for radial milling. The Dominator is programmed, machining commenced and the work-piece ground to tolerance in about four passes. Post-manufacture dimensional checks using CMM equipment reveal a zero failure rate.

Details available from Jones & Shipman International. Tel: +44 (0) 116 289 6222, Fax: +44 (0) 116 289 2945.

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