The weight drops the top ramp, which collides with the metal ball. The metal ball rolls down a series of ramps and collides with a rod that releases the spinning circle. The spinning circle travels down as it spins, which eventually pulls the large hanging metal ball loose. The ball drops slowly as it unwinds, turning the windmill. That eventually pulls a pin holding the ice. The ice slides down the tube and drops into the pitcher. During each collision energy is transferred between objects.