Jessica Bethune, Aiswary Kolisetty, Jessica Noglows and Rob Sobecki built this Master Lock Cracking project. I could have used this in junior high when I forgot my combination and needed to get my lock cut off. There is a mechanical spinner and a puller, the rest is all PIC microcontroller code.
“The PIC was required to interface several hardware components to crack open a MasterLock with our LockCracker. The PIC had to turn the stepper motor clockwise with the first number of the lock’s (possible) combination, counterclockwise with the second number, and then clockwise again for the last number. To do so the PIC sent the stepper motor a consistent step wave that with each high value tells it to step once, and with every low value cuts off the step of the motor. The motor was wired to avoid microstepping and instead turns 1.8 degrees with every step. With 40 numbers on the combination lock, approximately 9 degrees of separation exists between each number. Each number on the lock is traversed by 5 steps from the motor. “