I tried different projects from here, and I took the best from all the tries. The angles allow an easy and fast unwinding just by pulling the two ends of the cable. This cable winder has also been designed for stiffer or longer cables with a little more room for the spool. It has rounded edges, and if printed on a rough surface, it creates a non-slippery surface. It also has plenty of room for the thumb and index fingers to rotate the coil, with rounded edges for optimal comfort. For the case, just create two copies so as to have two halves, and the symmetry allows putting together the parts with high precision, thanks to the positive and negative pins, and keeping them together with glue at the corners. Next step will be to design with snap inserts to allow easy open&close.

The sample has been printed with an Elegoo Centauri Carbon with the Standard 0.4 PLA preset.

The design allows for printing it with no supports at all.

UPDATE: I added the clip system. It fits perfect to me printed in PLA with Elegoo 0.12 fine setup with the 0.4 nozzle

Original idea from: https://www.thingiverse.com/thing:2281191 This is an amazing project