Made a thing

A project log for Minamil: a minimal CNC mill. And friends.

Each axis: ̶$̶5̶ ̶$̶8̶ $10 motor+lead screw, 3x LM6UU, 3x 6mm x 100mm rod, 1/8in hardboard, PC case screws

Paul McClayPaul McClay 08/30/2020 at 03:330 Comments

Apart from an initial attempt and unsurprising failure to cut out the part at Q, I've just been trying to cut clean pockets without trying to cut out parts. The last log ended with the pocket at R which I'm willing to call "pretty good".

So it's time to try cutting a part!

It helps that exactly one month ago Stewart Allen checked in a "wide cutout" option for Kiri:Moto. That solves the cause of predictable failure at Q above (actually the failure is under W) without any other CAM gymnastics.

This time I double-stick taped the material in place. Kiri wanted to cut the part outline as part of the roughing operation before finishing the curvy bit. Kiri does support tabs, but I didn't want big tabs and didn't know how unbig the tabs could get without messing up the finishing operation. So, tape.

"Send File"...

click or see gallery for full resolution

...and this time it worked.

pocket has four beautiful straight flat smooth sides -- click or see gallery for full resolution
20 contours/mm - done that once prolly don't need to do it again
Ok, that's a cheat - I can squeeze the plastic more or less to dial-a-dimension

Relative to my subjective hopes/expectations for this project, I'll say that turned out well.


Next: try conventional milling without augmented lead screw inertia.