Since 2004, Seco Tools has been working with landing gear specialist Messier-Bugatti-Dowty (MBD) to develop efficient methods to machine the high quality, complex titanium components used in today’s aircraft.

Despite the manufacture of large structural components for aircraft landing gear being a primary activity at the UK division of MBD, the challenge presented by the truck beam on Boeing’s 787 Dreamliner proved a test for the company. There were two main reasons for this – the specially-developed 5-5-5-3 material (a next-generation of titanium alloy) used in the truck beam; and because no suitable cutting tools and little cutting tool data regarding the machining of the material existed back in 2003 when the project started.

The material was selected due to its impressive strength-to-weight ratio, a benefit in the aerospace industry where even a 1% saving in aircraft weight can result in 3% less fuel burn.

However, with over 130 tonnes of down-force expected on each truck beam, quality components and parts are essential; and with each billet of 5-5-5-3 costing many thousands of pounds, producing scrap was not an option, especially as the project represented MBD’s first commercial landing gear contract for Boeing.

To meet the tooling requirements, the company selected a six-spindle DST Droop & Rein CNC milling machine from Seco. The solution is based on

the use of an 80mm diameter helical cutter (R220.69 Power Turbo) plus copy mills (R220.29) fitted with five modified 20mm button inserts (RPHT.2006) that use a special variant of carbide grade – T350M. The cutter is used to profile-plunge mill the forged billet, an operation that roughs away approximately 30mm of stock from the component surface.

Both companies are now working together, looking primarily at coating technology, to improve the process further.

Seco Tools

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