This model is very simple to assemble. Print all the necessary parts, including the two gears. Then, assemble the model in the following order: wall, gear, shaft, gear, head, top. Make sure the two gears are positioned so that the pins on the head align perfectly with their holes.

There’s only one way to align the two gears: you have to position them by rotating one 180 degrees relative to the other. There should be no force needed to insert the pins, but most importantly, there should be no resistance when rotating the NEMA 17. If you feel any stiffness while turning the shaft, it means the system isn’t properly aligned.