had a issue with breaking guitar string winders. so ive come up with my own solution. 
 

An way over engineered guitar string winder. 
It needs the following parts:

2 x F695 2RS bearings.

1x BHCS screw M5 

1x 5mm washer

1x M5 heat insert OD 8MM

easy to print. 

Use some extra walls and infill to last it a lifetime.

1 part needs some aditional supports.

I recommend:

5x walls (perimeters)

4x top layer

4 bottom layer

40% infill.