For this to work you need to print 2x Winder.stl and optionally M8 Thumbscrew.stl (you can get without it).

Hardware you'll need:

• drill
• M8 threaded rod (15-20 cm)
• 5x M8 nuts (or 3x M8 nyloc nuts)
• 3x M8 large OD nuts

1. Screw 2 nuts from one side, the first about 3 cm from the end of the rod (this end will be held in the drill chuck)
2. Tighten them against themselves
3. Add washer
4. Add 1 Winder with larger part to the washer
5. Add another washer
6. Screw a nut and tighten it against the washer and the Winder,
7. Add another nut, tighten it against the other and the assembly is pretty much done

I recommend printing this in ABS or PETG. You might want to use a glove to hold the filament and wind it tightly on the spool.