The part is about 7″ by 10″ and approximately 3″ thick. It was a challenge to machine because the wall is only 0.200″ thick and required special measures to keep vibration and distortion under control. Over 30 programs were needed to run the part and the total runtime and programming time was almost 40 hours. The material is Alumec 89 aluminum. The raw block weighed almost 25 lb (11.5 kg) and the finished part is 14 oz (390g).

1. TOP VIEW: The part has been milled, handworked and fine glass beaded. The logo was milled using 1/32″ diameter cutters and stands about 0.150″ tall. It is proud of the surface by about 0.025″

2. TOP VIEW #2: A view from the other end

3. UNDERSIDE VIEW: This side was milled first.

4. HALF MACHINED IN THE MILL: This part is being milled in my Haas Minimill. The underside is already finished and the first 2″ of the top is roughed. The red stuff peeking out at the corners is Plasticene used to dampen the vibration as the part is milled. The Plasticene and milling strategy of cutting it in 2″ sections was the only way to keep the part from self destructing during cutting. Blending of successive sections was done by dropping the cutter in small increments until the new cuts just kissed the previously milled surface.