Spiral Ball Launcher: spring potential energy converts to kinetic and gravitational potential energy in this fun 3D print. A variation on the spiral “impossible passthrough” fidget toys, the ball exits the stack of rifled guides with stabilizing spin along the vertical direction. The interesting behavior stems from the connection between translational motion and rotational motion and the precision manufacturing allowed by the 3D printing process. Another amazing creation by RJ Design.➡️ Follow t