Coffee grinder clutch gear replacement

Printer settings: PLA, 0.15mm Quality, 100% Infill

Modeled in FreeCAD!

This is a replacement clutch gear I modeled for our kitchen grinder. Despite a very light workload (kitchen spices), our original gear suddenly exploded one day. I suspect repeated thermal cycling in our dishwasher may have weakened it over time (ain't gonna be doing that anymore with a 3D printed replacement).

This is designed for a Chefman brand grinder, model MEC-5256U. I've also heard it called the MEC-5256, which I assume is the same product (?). It may work on other models and brands too for all I know.

It takes about ~34 mins to print on my Prusa i3 MK3s with the above settings. I chose 100% infill to keep the part balanced as it will be spinning at a high RPM. Just do it, it'll only add 2-3 mins to the overall print time ;)

When installing, stick your hand inside the cup and hold the blade steady (it's not sharp-sharp but be careful) while unscrewing the hex nut on the bottom with a pair of pliers. Keep the little plastic washer on the bolt. Drop the removed nut into the replacement part's hexagonal pocket and, with your fingertip pressing the nut down down so it doesn't pop out, screw the whole part down firmly onto the shaft bolt. The part may be a tad thick initially causing the shaft to not rotate freely, and that's OK. I was a little worried about this until I ran the grinder for a couple of seconds and things immediately freed up (heat melts PLA it seems).

Enjoy! And keep it out of the dishwasher, at least with this clutch gear attached.