MTM Snap, aluminum casting

Since we do not have a Shop Bot, we decided to make our first MTM from casted aluminum. We were able to make all the parts but without some serius machining it is impossible to get the tolerances necessary for the MTM Snap. This was an awesome experience, it was the first time I did aluminum casting, so HOT :).

MTM Snap, using HDPE and the shop bot

After asking around campus who had a Shop Bot and if we could use it for a project for the Fab Lab, finally somebody was convinced enough about our project and agreed to cut the MTM using HDPE and.

MTM files (this includes the hole file, for holding down the sheet of HDPE, the test part, a small snap, and of course the tool path).

MTM BOM file

Shop Bot toolpath settings for 1/2" HDPE:

drilling:
tool: 3.1mm drill bit

plungerate: 10 inch/min
spindle speed: 2k rpm

milling:
tool: single flute up-spiral 1/8" endmill

pass depth: 1/8"
feedrate: 30 inch/min
plungerate: 15 inch/min
spindle speed: 14k rpm

Jonathan Ward MTM page

MTM Snap, assembly

MTM Snap, programming