Auto-Rewind Spool Holder (remake for MMU under shelf holders)

I added the square end stop to the spring so that it would work with my spool holders and not need a cable tie. It prints all as one piece.

The link to the rest of my Spool holder to go with this is here.....

https://www.thingiverse.com/thing:3248102

*** Update *** 8th May 2019 Added new Spool and Spring files, they now push in to each other instead of just have to glue two flat pieces together. For mine they were a tight fit and I did not need glue on these new ones. If still a bit