This is my take on a simple and affordable rock tumbler. I recently started printing with materials such as PrimaSelect Metal Bronze which is a composite material made from 20% PLA and 80% bronze powder. My goal was to create small bronze statues of family and friends by printing and polishing scanned files.
I came across the ”Affordable Rock Tumbler” made by J_T_3_D and thought that the basic idea was nice, but I wanted another frame, a printed and isolated drum and belt drive instead of two herringbone drive wheels. Therefore I set out to design my own version of the tumbler.
It uses the same motor as the original design, the same amount of threaded rods but more printed components. For instance, to print this you’ll need access to a flexible filament as well as PLA/PETG or whichever you prefer to print the frame with. There is also a secondary front frame that you can attach the motor to if you don't want to use a flexible washer (reduces noise).
The BOM is as follows:
- 30X M8 nuts
- 16X M8 washers
- 1X 230mm M8 threaded rod
- 1X 250mm M8 threaded rod
- 4X 245mm M8 threaded rods
- 4X 608 ball bearings
- 3X M3 nuts
- 3X 10mm M3 screws
- 6X 6/10mm M3 screws (6mm with washer, 10mm without)
- 12V power supply
You’ll also need a 12V DC motor. In this case I recommend an RB35 motor with a diameter of 37mm. Product link here.
In the back portion of the frame I also left room for a standard 13x18,5mm DC power rocker. In case you live in Sweden you can pick one up at Kjell & Co. Product link here.
In order to tumble properly I recommend a mix of brass and iron screws. Leaving a part in the tumbler for about 6-8 hours is usually enough to give it a really good shine.