The castings are made to a material specification called RR50-created by Rolls Royce. "It's exactly the same material and part design as it was when the Merlin engine was first run, in the early 1930s. It would be relatively straightforward to modernize aspects of the engine design - to remedy small design faults - but the demand is for authentic parts, without any changes from the original," Faulks mentioned.

This particular batch of cylinder heads - seven off - will take us two years to finish and deliver to the Royal Air Force. Tolerances - between the arrays of bolt holes, for example - are 0.025 mm. Each face takes around a week to machine; the inlet/exhaust faces take another half a week. All the programming is done offline on OneCNC.

"The new Haas has enabled us to keep more of this type of work in-house, and not rely so heavily on subcontractors. As a company, that's the general direction we are heading in. To do so means making an investment, of course, but the difference between the parts we used to get - or make in-house on old machines - is night-and-day. The repeatability of the Haas is excellent, and it's very reliable and easy to use," he noted.

"Although we can't change the design of the parts, we are machining them to a higher standard, which, in itself, is a big improvement," Faulks concluded.

END