As promised, here is my string winder, this is my version 1 :
To be fully honest, this string winder has a big drawback, it is it must be used with both hands.
But actually, it is fast, and in the shop, I use it with a third hand, which is a long rubber strip hanging from the ceiling and that pulls the string of the instrument which is hold in my luthier vise.
But when I'm not in the shop, this is not very handy.
But this tool is quite funny to build : the rotating head is made in two main pieces, glued together after passing through the eye of the handle.
The rectangular hollow shape is actually made in several pieces, cut and reglued together before turning it round.
See also my new version 2...