This replaces the insert for the ceramic burr in your Java Presse coffee grinder. The original piece on ours cracked and stripped out the notches that the metal shaft grabs to spin the ceramic burr.

The original is nylon. I highly recommend printing it with nylon. I used Taulman 3D Nylon Alloy 910. Alloy 910 is an FDA approved material for direct food contact.

This version of the part fits the metal shaft a little tight. The advantage of it being tight is that it is less likely to strip out the notches than if it is loose. The disadvantage is that it wont slide freely on the shaft, so you have to give the burr a little help when you loosen the adjustment knob by pushing the shaft with your finger. I provided a step file, in case anyone wants to adjust dimensions to get a looser fit.