Sherline CNC Mill - Vacuum Clamp

My friend Jay from MotorCity WatchWorks asked if I could machine some custom watch discs for him and always wanting a challenge for programing and machining I said I would.

The 1st part of the project was to figure a way to hold the feather weight 1.125" dia. x 0.025" thick watch discs without damage and in a way that would allow for quick operation. I decided to try and make a vacuum clamp and so came up with this little number.

This block of aluminum has the grooves for clamps, a threaded hole, pins to align the disc, and an O ring for sealing. The alignment to the center hole is off a little so I'm going to have to do a test piece and adjust X, Y, for the final set up, after that I just throw the next one in, turn open the vacuum valve and start the program. The natural pattern from the shell becomes the artistic part of the process; I look at the pattern in different rotations and decide how I would like the waves and curves to look for the finished piece.

The discs are machined out of Mother of Pearl shells and the pattern that I machine is designed by Jay. I cut the pattern about 0.007" deep and Jay adds watch lum into the pockets. The whole milling takes 2min - 28sec. using a 1/16" end mill.

The Z height had to be tuned to minimize the depth too, now that I think about it I set up off of the fixture top and not the top of the O ring!

This is just one more use for for my JoeWoodworker vacuum system.