PUT A DAZZLING POLISH ON YOUR ROCKS with Polly Plastics rock tumbler grit and polish refill. Our one-of-a-kind rock polisher kit contains four different kinds of grits to provide initial shaping ...

To make a basic rock tumbler, all you really need to do is rotate ... Pulsing the electromagnet pulls down the large 3D printed spring, which imparts not only the vertical motion you’d expect ...