String Winder (drill or hand crank)

Winding tool for changing strings on instruments using geared tuning machines. Head can be used with the detachable hand crank or attached to any standard hex bit for use with a power drill. Print in orientation shown in picture for maximum strength (though will print vertically oriented if your printer struggles with holes in that orientation). I used 6 perimeters for strength (it almost prints solid anyway due to size), no supports.

Crank pieces connect with a 20 mm M3 screw and M3 nut. Use a nylon lock nut or threadlocker to prevent unscrewing while in use. To ensure the handle can spin freely, do not overtighten the nut, and you may need to run a drill bit through the hole to round it/clean it out (depending on your printer).

There should be enough depth to use with a drill driver bit in the "normal" direction (driving head facing out of the drill), but if you use it reversed in the chuck as shown in the picture, it will be more stable.