How I built a quick and easy home-made ball mill
How I built a home-made, quick and easy ball mill, that can also be used as a rock tumbler. ... To use the mill as a rock tumbler, just leave out the steel balls, add rocks, ... So I found a scrap piece of aluminum and mounted it the end the drum ... I went with 5/8 inch diameter balls, which seem to work well in a mill this size.