I’m making one out of a treadmill that I snagged over Covid (and subsequently never used)! Idea is to make a jig to hold the tumbler in place. Maybe make it removable so I can still choose to not use the treadmill.

Spindle wheel and belt to adjust speed. Rigid hold-down for motor. Slideable positioning of bucket to accommodate the belt setting. Plywood base. On/Off switch with shielded wires. Done.

You are… broom! This isn’t me but here’s the idea: https://m.youtube.com/shorts/nOVFA7Kt44M

If I make a broom the spindle I will immortalize your username onto the wood base with a soldering iron.

You did see how long it takes, right?

nnno, I did not see that. 7 days is an awful long time to run a treadmill; not worth the energy for that use case.

I had mistook the tumbling mill for the ball mill, which is used in shorter durations for cast sterling silver polishing… I have been into lost wax casting of late