This is to ragecgi or anyother dynamic expert
 

I don't know if you remember the mouse trap board game. For class I got to model and animate the hole game using just dynamics. I'm having problem doing the rubber band effect. The crank turns around and moves the stop sign and streches the rubber band back. When the crank passes by the stop sign shoots back with the rubber band going back to its postion and hits the boot.

I've tried about everything I could think of. Can someone help if they can.

Have you tried putting a skeleton in the rubber band? I've done this for ropes and stuff and it gives you a lot of control.

Sorry just reread and saw the "just dynamics" rule. Sorry. mmmmm that's a toughy.

Without doing lots of tests, I would say take a look at soft bodies and goals. That should point you in the right direction until someone with real experience in this has time to come to your rescue.