MACHINE AND MEASURE COMPLEX CHUCK AND SHAFT PARTS IN ONE STEP

Flying in a modern aircraft with strong jet engines, comfortable seats and a well-balanced air conditioning system, passengers seem to be close to heavenly comfort. Manufacturing engineers in the aerospace business, on the contrary, are often experiencing hell with high-tensile alloys, weird design, unprogrammable curves and tight tolerances.

Manufactured aerospace parts tend to complicate shapes due to weight issues, which make a series of machines necessary for production. This requires adequate fixtures and multiple setups in lathes, machining centers, grinders, deep hole drilling machines and more, resulting in lengthy floor-to-floor times and high manufacturing costs.

The solution to this problem is offered by WFL (Werkzeugmaschinenfabrik Linz), who exclusively focus on multi-task machines under the trade name "MILLTURN TECHNOLOGIES". In a single machine tool, WFL's MILLTURN machines are a combination of a 2-4 axis turning center and a 5-axis machining center. According to the company, they can perform all machining and measuring operations on extremely complex chuck and shaft parts in just one step.

It is possible to combine up to 18 individual operations on jet engine shafts into just first and second clamping in a single Millturn machine. Whereas the old method meant a lot of accurate set up work, the new process combines OD-turning, ID-turning, milling and very accurate drilling.

Boring bars up to 5ft are stored in a separate, heavy duty dove tail accommodation when used. In addition, the changing of long tools is entirely automatic. For shorter ID-work up to 20 in., a boring bar base with exchangeable tool head is used. The tools come out of the same magazine as all other turning, drilling and milling tools. The magazine is located at the front left side of the Millturn machine, and can be operated without interrupting the machining cycle. Many customer shafts require a positional tolerance of timing holes on a flange to the center bore of only 0.001 in. This is accomplished by the Millturn machine in a fully automatic cycle, which involves the in-process measuring probe. Linear glass scales, roller bearing guideway systems—which provide a stick slip free motion of the slides, and a smart measuring cycle by WFL are necessary for achieving this kind of tolerance.

Combining all work to just two operations means a dramatic reduction in setup work, inspection and off-line measuring. Employing this concept, savings in manufacturing costs are generally between 30% - 50%.