Summary

I found a manual coffee grinder online that was great except for the loose tolerances that let it strip itself out from normal grinding.

Instructions

I'll probably print this solid, just to be sure. The drive shaft that slides into it has pinched-out fins that have a generally rounded character, so any extra rigidity is desirable.

First revision lacks grind select ridges on the bottom, and is sized almost exactly for the shaft. Might need some loosening to allow smooth/full function. If your peer down from above, you can see the difference between the original gap(toward the middle) and actual dimensions of the shaft.

Unscrew and disassemble the grind drivetrain. Snap the original plastic mount out of the grindstone, replace it with this one, and reassemble. Finally expresso and turkish grinds won't cause it to self-destruct! (I hope)

coffee grinder part