Lego Ball Pit In Our Color Scavenger Hunt! Senate votes to avoid government shutdown as 10 Democrats vote with Republicans Powerful Tugboats Pull Massive $13 Billion US Aircraft Carrier to the ...

This is a ball mill used for refining materials into a fine powder. [Jpoopdog] built it in two parts, a base and the tumbler chamber. The base itself is build using LEGO wheels as rollers.