Algodoo

Set the sim frequency to 500 before un-pausing the simulation.

To Use:

Gently push the key into the lock. When the key is in as far as it will go, pull the pin outwards to unlock. To re-lock, push the pin in and gently pull the key out.

DO NOT pull the key out when the pin is out, or you will break the lock. Pushing or pulling the pin is supposed to simulate turning the key, and you wouldn't (and couldn't) pull a key out when it was turned.

The problem with this lock is that you can't pull the key out and keep it un-locked, so anybody could come along and lock the door it's attached to.

So, pretty much, you have to put the key in and turn it to un-lock it, and take the key out to re-lock it. If you pause the simulation and move the key out of the lock, it will stay unlocked though.