PolyDryer Box Auto-rewind Spindle Spring Cap Rebuild

Although the auto-rewind spindles for the PolyDryer Boxes have worked well for over a year, one of them recently stopped rewinding. After some fiddling about with all the usual suspects, I dismantled the spindle and found this inside:

The spring tab barely visible below the separated filament layers normally fits in that slot, but now rotates freely as the spring turns with the spindle’s axle.

A short while later:

The minuscule carbon fibers in PETG-CF don’t improve the layer-to-layer adhesion and may make it worse, particularly in designs with very small cross-sections.

I use PETG-CF mostly because I like how it looks, as few of my designs require even moderate tensile strength.