just lock the gear into place with the torsion spring...
unfortunately for the originator of the hack, eventually the spring stretched and allowed the gear to move just enough to climb on top of a tooth, which locked the knocker coil on...
what is somewhat amusing is that someone went to GREAT lengths to try and stop the knocker coil from buzzing (it is really fried, what with being locked on for who knows how long, but it still works)... it was REALLY loud... i wish i had taken a picture of the attempt they made to isolate the bracket from the cabinet with a big hunk of foam...