Rewinder Spring Redux

This is a remix of the spring used in VincentGroenhuis' awesome Universal Auto-Rewind Spool Holder.

I use 5 of these on my Prusa i3 mk3s MMU2.0 setup as a replacement for the prusa fiber buffer. They reliably rewind fiber onto the spools each time the MMU tool changes which fiber is going into the extruder.

The remix replaces the spring and housing.
I found the bi-directional spring to be too fragile for the long rewind lengths my setup required. This replacement only acts in a single direction, you want it oriented so that the spring winds up into a tighter and tighter bundle as the spool unwinds. This is more robust.

Print each part individually. I use PetG material. The Customizer should let you change the thickness of the spring to make it apply more or less force.