I made a rotary tumbler device for metal cleaning (mainly knife blanks) from stuff I had in the shop. The goal is to somewhat “polish” the metal before further treatment. It’s made of a 12V-Motor, some scrap wood and a wine bottle tube.

I used plain and ordinary grit as grinding medium, but I think it’s not the best solution overall. The before/after images show the completely untreated piece of hardware store steel and the outcome after around 8 hrs. of tumbling. Might do some more research on what grinding medium should work best.

If you want to make your own:

– 12 V DC Motor (this one, off eBay), 10 rpm
– Wine bottle packaging tube, as long as your metal parts
– 2 furniture rolls
– Some scrap wood
– Piece of plastic as a “stirrer”

The construction is self-explanatory. Do give it a try!