I needed grinder for bigger pills but none of I found are any good. Most had too weird/tight thread on screw part or was just too slippery in hand.

 Beside classic threaded hole I added small protrusions on top of grinding part that help crush pills and I made grip part in form of triangle for better grip.

I used PETG filament with 0.2mm layer high. No support Default infills.
Recommend using Hilbert Curve for bottom surface as it look nice.
Picked black for bottom part as its easier to see if any remind of previous pills are inside.