Chaos balancer

This is a balancer made for an 8mm shaft. Print two of them, fill the inside chamber with particles that can re-settle and are heavier than the correction weight, but not more than 2/3 the chamber volume. When it spins up, the vibration causes the particles to re-arrange untill they hit an equilibrium with the unbalanced mass, at which time the vibration stops and the particles stop moving. (its used in CD drives)