6 turn 1.4x1.5mm 1.4mm gap spiral

thingiverse

A Handmade Gearbox Created by TheOriginalBaldGuy This thingy was designed to be a hand turned gearbox. With customised dials it makes an interesting pen holder when attached on the desk in front of you. The main gearbox housing and pen holders are produced using Fused Deposition Modeling technology, but you will require two gears (the drive gear & idler) as well as small hex head bolts.