Mostly printed tumbler

If you print with bronze, copper, aluminium or steel filament, this can help you with the finish afterwards.

* Print all parts once
* Print container-cap.stl one extra time (so you have a cap at both ends)
* Print locking-plug.stl three extra times

Get four skateboard ball bearings (normal)
With the locking plugs, attach them into the frame.
Get a geared electrical motor:

From amazon:
https://www.amazon.com/Cylewet-Motor-Shaft-Arduino-CYT1037/dp/B01N9MS3UZ/

From kell.com in S