Spool clamp for filament refills

This clamp system lets you reuse an old spool with a spool-less refill.

You'll need:

• An old spool (plastic or cardboard) w/ a 25-65mm hole;
• Two 3-5mm tie-wraps, length should be at least 2x the spool's width + 45mm.

Instructions:

1. Print 2 clamps narrow side down;
2. Separate the sides of the old spool by sawing them off the central tube;
3. Sandwich the new refill spool between the old spool's sides;
4. Put the clamps on the sides, narrow side towards the inside;
5. Pass one tie-wrap through one of the holes in the clamp, then through the facing hole on the other side, then pass it again on the same side but on one of the other closest hole (not diagonally), and finally through the facing hole on the side where you started;
6. Zip the tie wrap but don't tighten too much yet;
7. Pass the second tie wrap through the other holes, in the same way you did for the first;
8. Make sure everything is well centered: Clamps, sides and the cardboard tube on the refill spool;
9. Tighten the tie wraps as much as you can, preferably using pliers.

The spool is then ready and can be used on most types of holders. For holders that have a pole going through the center of the spool, the maximum diameter the pole can be is 9mm.