Basically, a really strong cone that moves around the inside of another circular, hard surface slightly off center. You dump rocks in there, and as it spins around, it opens up a small gap. The rock falls in, and then it continues to move around, crushing it. Only rocks of a certain size can fall through the larger ones get crushed.
Basically, a really strong cone that moves around the inside of another circular, hard surface slightly off center. You dump rocks in there, and as it spins around, it opens up a small gap. The rock falls in, and then it continues to move around, crushing it. Only rocks of a certain size can fall through the larger ones get crushed.