This model prints in place, no assembly required.  After the print completes, turn it over and gently pry the large gear loose working your way around the circle to break it free from the upper housing.  Do the same for the small gear.  It takes a bit of effort to break the gears free, but after a little clean up they turn well.Print in PLA, with a raft, but no supports.  0.20 mm layer height, 10% infill.https://www.youtube.com/watch?v=pn2wbJqMqCAhttps://youtu.be/lVy8cAtBhTA