Algodoo

SawStop

Modeled after a real product called SawStop.

http://www.sawstop.com/

In real life, table Saw prevents cutting off fingers by detecting contact with finger, stopping saw within 0.005 seconds, and retracting blade. Blade is retracted by momentum of stopping blade, not by a motor.

The video of the real saw stopping is much better than this scene.

http://www.youtube.com/watch?v=E3mzhvMgrLE&NR=1