Animations of mechanical models

Original model

(9)-1 Quick return motion

The green arm is rocked to either side by the pink pin on the rotating disk. The arm's rock is larger when the pin is close to the fulcrum (where the arm connects to the base), and smaller when the pin is further from the fulcrum. Consequently, the blue crosshead moves to the left slowly, and returns to the right quickly. [Animation: DI JING, Graduate school of informatics, Mar 2000]