Yet Another Combination Lock (Changeable Combination)

You will need a spring. If assembled appropriately this will allow you to change the correct combination even after assembly

The "code" gears (you'll need 3) will go on part 1 (print the pins if needed. M2 screws are better, of course, as long as you can find a few that are not too long). Use some whiteout maybe to allow writing the numbers on there.
The "driven" gears (you'll need 3) will go on the cylinder part 2

To change the combination: press down the pin when the combination is cor