A string winder for your guitar or other stringed intruments. The winder is is intended for when you change strings and should be used in concert with a cordeless drill or electric screw driver to speed up the winding process.Use the drill to wind or unwind the slack string onto the tuning head. There are two parametric SCAD files that allow you to size the winder body to your own particular instrument.My prefered implimentation (string_winder_002.scad) would be to RP the body and use a short length of hex key to inteface to a drill or other winding device. You can select the size of the hex hole in the openSCAD file. I have provided models of 3 typical sizes, for a strat type guitar, a single cutaway type guitar and a classic bass all with a cutout for a 6mm hex drive. The other implimentation (string_winder_with_stem001.scad) has an incorperated stem so the whole device may be RP'ed. Again as well as being able to specify the size of the machine head you can specify the size of the hex drive.