Cid's Despooler (save fishing line in good shape for re-use)

Edited from original post to add a version where a work colleague showed me a different spool type (4 spoke) and only had 5/16" bolts to test with. Print options have both 3/8" & M10 (10mm), and 5/16" & M8 (8mm) options in both standard and carriage hole variety).

As I like to change line to my purposes (Flourocarbon, braid, surf fishing, etc) and flourocarbon/braided line aren't really all that cheap I was looking for a despooler. I found several on thingiverse that would have worked but I would have had to print one each for every batch of line with the potential for abrasion on the spool itself if I had any ringing. Instead, I went the route of making a locking hub piece so that a drill could be used to make it easy and I could control the wind positioning to minimize twist. This isn't a complicated design by any means and is merely meant to use parts I had laying around but should cost around $1 or less if you have to acquire them. I had 3/8" bolts laying around but added a carriage option since they're easier to find full length threads and you'd only need one crescent wrench to remove the spool.

The 120 degree models work with 3 and 6 spoke spools and the 90 degree model will work with 4 spoke (8 should work too if there is such a thing). Smaller spools such as braided 100y packs work but you can only need 1 hub. I like a pair of them for larger 22mm types (Trilene, Stren, Sunline, etc) and put them together with a 2.5" / ~60mm bolt with a few fender washers to protect the hub from the bolt, a couple washers to get past the unthreaded part, and a nut to hold it together. If you're using carriage bolts it's even easier since they're threaded all the way so you could make it shorter/lighter.

Printing:
Should be printable in any material, pick your poison. I used PETG for my first, PLA (annealed for heat resistance) for my second.

I used 20% infill on the PETG print and 100% for the PLA one. If I did the PETG one again no more plastic than it uses I would probably just keep it at 100% personally. Should be printable on any thickness. I used 0.2mm with a 0.4mm nozzle.

I created it to print flat side down with a slight lip allowing for easier removal but they'll print just fine without support.