These gears were disigned mostly as a printing test, but are also kind of fun to play with. The teeth of the gears have a tractor wheel like profile to keep them alligned. Note that printing the gears can be challenging because of the many tiny teeth.
Important: You cannot push the pins through the small gears by brute force. You need to carefully push the sides of the pins inwards so it fits through the hole.
The bottom plate (the one with the holes) has a top and bottom. The side that should be facing the gears has an indentation that goes horizontal, while the side that should be facing the outside has a sloped indentation.
This side should face the gears