New Edgecam CNC software supports Bloodhound Project

AN ESSENTIAL part of the assembly holding the rocket motor in place when the Bloodhound supersonic car travels at over 1,000 mph has been made using Edgecam CNC software just in time for its bid to break the World Land Speed Record in 2016.

“The accuracy of Edgecam’s tool paths was vital in allowing us to achieve the extremely tight tolerances required,” says Andrew Wright, production engineer at the Sheffield-based Nuclear Advanced Manufacturing Research Centre – manufacturer of the rear sub-frame for the car, a large complex assembly which sits inside the exterior Titanium skin.

The Bloodhound Project

The Bloodhound Project led by Richard Noble, who took the record in 1983 with Thrust 2 aims to excite young people about manufacturing and engineering. The car is a mix of automotive and aircraft technology, powered by the engine used in the Eurofighter Typhoon aircraft, along with a hybrid rocket.

The body and chassis are relying on a range of advanced design and manufacturing techniques, including a specific production engineering solution with Edgecam that prevented distortion of the rear subframe side wall structural panels. The 1.6m x 1m panels were produced by the Nuclear AMRC on its Starragheckert HEC 1800 large format horizontal boring machine. They have to mate up with other parts in the rear assembly which are vital in keeping the rocket pointing perfectly backwards and providing downward thrust when RAF fighter pilot Andrew Green drives into the history books in South Africa in 2015 and 2016.

While the typical machining tolerance for milling was + or – 0.1 of a millimetre, some of the wall thickness tolerances were + or – 0.05, and hole diameters down to + or – 0.025. “Also, the original billet of aerospace grade 7075 aluminium was 80mm thick, and the finished component is 20mm, with some minimum wall thicknesses just 6mm. Removing such a large amount of material while maintaining the flatness and shape of the component over that size and envelope of machining, was quite a challenge.”

Couple that to the fact that the billet was only around 30 mm longer and wider than the finished part, and it is easy to see why Andrew Wright’s experience in finding correct production engineering solutions across a variety of projects was essential.

Edgecam’s advantage

“My main concern when I started programming was that the part would distort and we’d struggle to maintain wall thicknesses. If some of the walls became too thin, the component may not have been strong enough,” says Wright.  But he says Edgecam’s roughing strategy and profiling cycles were perfect for his solution.

“We used a three-side machining strategy of roughing one side out, rotating the component and roughing the opposite side then we released it and reclamped it to finish machining that side. We turned it back round again to finish the side we’d started cutting originally. That way we minimised distortion and any chance of having the walls too thin.

“I built the machine setup in a 3D design package and Edgecam allowed me to import this directly intADIDAS