This is a really cool Gear ratio box that could go up to 14 gears. There is also a hand crank version available. Since it is a 1:3 ratio, the gear rotations multiply by three every gear (1, 3, 9, 27, 81, 243, 729, 2,187, etc.) I started by hammering in the two rods into the normal base, and then I put each gear on small gear side down, alternating sides each time. I then hammered the top base on (Crank and/or normal.) If using the crank version, insert the crank into the small side hole and put the crank gear on, and then hammer the base on the rods making sure that the crank gear is making contact with the top gear. Finally, your gearbox is done and assembled. I would recommend printing in sport mode, makes printing faster but it still works perfectly.