small gear box

thingiverse

Update 9/14/18: I've completely reworked this gearbox with higher ratio gears and better mesh between them, making it more reliable in operation. My plan is to create an adapter to convert this box into a self-centering steering box. I recently visited Walmart to find nails, but they didn't have anything suitable. The mystery of the missing nails has been solved; they're 10-gauge roofing nails. In my collection of hangers, I've also found some with a 2mm diameter, so you should be able to find something around the house for shafts without having to make a purchase. This gearbox is only a two-stage design and will easily be modified for a four-stage version in v2. For the shafts, I used a nail that I couldn't remember what it was originally for but measured exactly 3mm; I think they're roofing nails as well. To print the gears, use a raft to keep the teeth clean and sharp on the bottom; it's better to sand the raft than to clean the teeth. No supports are needed on the other parts. For a long time, I've struggled with downloading gearboxes from Thingiverse only to find that the parts don't fit, the gears can't be printed, or they're just plain non-functional. I have a huge folder full of these bad gearboxes and generally terrible experiences with them. The gear tooth pattern has been driving me absolutely crazy trying to get these small gears to print with enough meat on them to mesh with the others. I've tried all the gear generators for OpenSCAD, but my printers just can't print them properly. I've finally figured out the problem: it's best not to use any gear generator and make them manually. This gives me the ability to make the teeth longer for more bite and not put the point on the teeth, making them square. Who would have ever thought that when they're printed, they come out with a round tooth end? Since I've found Polaris GM gearboxes for under $10, which are really cheap and well-built, I may or may not make the four-stage version. This project was just to scratch an annoying problem itch.