So mine and Rok’s Rube Goldberg machine started with a Hotwheels car (Wheel and Axl) knocking a ball off of a screw (Wedge) then the ball rolling down a incline plane and landing in a cup activating a pulley then the cup on the other side of the pulley knocked over a domino which landed on a teeter totter (Lever) which pushed a ball down another incline plane and then the ball when through a screw then the ball knocking over more dominoes then a ball getting knocked over into a cup.