Check this out: https://www.youtube.com/watch?v=ic9dLWOwyYM
These spool winders look a lot easier to make than the older versions... the spring is entirely printed, as well. Needs eight M3x8 screws, eight M3 nuts and four 08 skate bearings... everything else is printed.
https://www.printables.com/model/292276-auto-rewind-spool-holder-for-reprack
Bill
I have built this last week I couldn't get to rewind as I needed but really easy to build
comparing to the filamintalist its not as efficient
I got mine from Aliexpress I bought the BOM from this link and printed the parts
https://www.aliexpress.com/item/1005007331401063.html?spm=a2g0o.order_list.order_list_main.35.60a31802p2JwPI
it was easy to build and works flawless I am planning to build 3 more