I looked a couple designs for string winders, but didn't see any I particularly liked. So I designed my own.

It's 3 pieces, has relatively close-fitting tolerances with lots of facets on the round parts, so it feels nice to use, and glues together with a drop of CA glue.

Put a tiny drop of glue in the pin socket from the back after you've partially inserted the pin, then push it the rest of the way.

Be careful to:
a) to not glue the knob to the pin,
b) to not seat the pin too tightly that the knob doesn't turn (the shoulder on the pin should prevent this, but it might be possible if there are printing anomalies),
c) make sure the pin is inserted facing away from the tuner pocket.

Prusa

I3 MK3S

Yes

No

.15

15

Only need rafts on the knob. It prints small end down to avoid supports.