Modular Spool Holder

Ok internet people, I spent way too much time on this, just so you could take a moment, print it once, and never use it again. But I love punishing myself in CAD and this was a good way to practice. I also wanted a model that required no supports and used minimal filament. Update: A note on alignment. The End Caps are marked with triangles and squares. One is LH thread, one is RH thread. Match them up to the barrrel like some sweet game of, well, Match. Also, I spent a silly amount of time adjusting the screw threads with chamfers and math and offsets so they actually screw in nicely. I mean this was something that really annoys me about models, so I seriously spent more time on this, than the rest of the model likely. Spoiler Alert about the Modular Spool Holder:It's modular. Yep, it's right in the name. But what is modular in this case? Each barrel (spindle?) holds a 1KG spool, but to attach the hooks you screw in end caps, which forms a cradle. But what if you want to attach