About this 3D model

If you turn the crank, small pulley #1 on axle A will turn larger pulley #2 on axle B. Pulley #2 on axle B turns pulley #3 on axle B. This turns small pulley #4 on axle A which creates perpetual . . . . no --- that can't be right . . . http://youtu.be/wv47-PJ5F1A Well, turning the crank is quite satisfying and a bit habit forming. At least the project prints in one piece.