This gearbox was designed to be a fun and easy build for a 3-D printer like the Makerbot 2. It has moving gears and uses 3-D printed bolts to hold the gearbox together. The STL files should be oriented perfectly so you can drag+drop them right into MakerWare! Because these are several moving parts, be careful resizing anything. I built this several times trying to get clearences between bodies to be very forgiving and allow smooth rotation. Hopefully this will work great on your 3-D Printer too.