Sometimes we humans need to build machines with the sole purpose of demonstrating the effects of gravity on a steel sphere. This is a machine that happily fulfills that purpose. Be mesmerized by the combination of engineering and physics resulting from the simple motion of turning a gear. Watch as the steel ball bearings gain potential energy as they're being lifted by the big wheel, only to be converted to kinetic energy as they roll around the well and tumble back to the bottom. Be amazed by the fact that this whole thing is 3D Printed.