Manual wire winch, with planetary multiplier

thingiverse

Update 2015-12-07: I've successfully printed this thing and discovered that the original design didn't assemble as intended. So I've updated the parts by switching from delicate nails to robust screws and introduced more flexibility between the gears. The winch now works flawlessly! The ratio is calculated by adding the number of teeth on the sun gear and the planet gear, then dividing that total by twice the number of teeth on the external gear. In this case, the calculation looks like this: (24 + 18) / (60 / 2) = 42 / 30 = 1.4. This means that after one handle turn, the winch makes 1.4 rotations. The 'sun' gear is permanently attached to the base axis while the handle turns the three planets, multiplying the rotation of the external gear, which is attached to the winch. No bearings are used in this design, so excessive friction might be a concern; however, with sufficient lubrication it should perform satisfactorily. Instructions All necessary STL files for printing are included and ready for use. Use only the files labeled Pl_ while discarding the file named Planetary3.stl, which represents an earlier version that failed to assemble correctly due to poor mating.