CNC: Replacement Parts and Aluminum

Over the last week I made a few parts on my CNC, one of which was made out of aluminum. The first part was a replacement part for a VR headset a friend gave to me. I accidentally broke one of the 3D printed adjustment racks and had to make a new one.

I made it out of HDPE, which is just wonderful to machine, due to its flexibility. I surfaced the material to thickness and cut out most of the profile with a 1/8" endmill. I used a cheap 1/16" endmill to get between the rack teeth:

Surfaced and most of the internal surfaces cut out.

Completely cut out.

Replacement on the left.

The next part I made was out of aluminum. This was a bearing block designed to replace the original wooden ones I made not too long ago. I didn't use any oil/coolant and it went fairly smoothly. Next time I probably would get rid of the lead in and lead out on the 2D contours and just use ramps. The plunge between each depth didn't sound great.

I used a 2 flute, 1/4" endmill for the whole process:

Sharp.

Cut out.

Reasonable surface finish.

 After cutting, the part was square as far as I could tell and had reasonable dimensional accuracy. The CAD model was 2.953" by 4.035", and part came out to be 2.960" by 4.034".

Square.

The hole cut out for the bearing was supposed to be 1.126" in diameter, but when I measured it it ranged from about 1.123 to 1.125. Had I taken a finishing pass I probably could have gotten closer and the bearing would have fit in. I had to sand the inside of the cutout with a Dremel to be able to get the bearing to fit.

Installed.