Update V2:

• Added a 0.3mm tolerance between the grinder pinwheels so that there's less chance of plastic dust accumulating if you spin it empty. They now float with a gap between them.
• Scaled the cap down slightly so the threads have a bit more room to breathe.
• Rounded the corners on the inside lip of the grinder so there's less contact with the top for less friction
• Rounded the grip on the cap so it can be accessed easier.
• All V2 parts are 100% compatible with the original uploads. No need to reprint everything.

Print at 0.2 layer height with at least 40% infill and 4 horizontal layers for the threading as it's a working part.

My Groovy Grinder has a hollow inside with a screw-on lid, so you can store unused ground material inside the grinder itself, making it impossible to spill after storage

I took inspiration from the pre-existing designs here on thingiverse and combined what I liked from all of them into this small piece here. I didn't use any of their files, just made my own from their inspiration.

You may need to work the threads a little to get them going smoothly, they are quite small. Tolerance is 0.3mm. I just use a pair of pliers to get them going then work them back and forth a minute or two.

Creality

Ender 3

Doesn't Matter

Yes

0.2

40%+