...if we take into consideration , the big size :
www.peswiki.com/index.php/Directory:Aldo_Costa's_Gravity_Motor
...and the small size :
www.youtube.com/watch?v=Rgp6gcSaF2Y
...of the same general idea (gravity motor/"perpetuum mobile" as a "wheel").
Al_ex
...about the size of the intended ( small...big ) experiments ( Leo...Aldo ) , have the same , unique design (starting "point") ,at :
www.peswiki.com/index.php/Image:Aldo_costa_relativite_200.jpg
Maybe , we must keep in mind the basic motion picture of gravity fall :
www.eoearth.org/files/116801_116900/116811/180px-Falling_ball.jpg
Al_ex