Summary I liked this design, but soon came to realize that when using smooth rod instead of threaded rod, that bearing's are really not needed, and tend to unspool themselves due to basically no drag. So I took this great design, and removed the bearing hole and replaced it with an 8.5mm hole to fit nicely over either threaded or smooth 8mm or 5/16" rod's and not require the use of printing with support. So no support, and No bearing's needed for these cool spool adapters! Was a bit more work than I had originally thought as when I exported the first few design's I realized that just filling in the hole still left internal gaps when slicing. All that has been taken care of, and I added a few more steps just because I could, and those tiny 5DF spools fit too :) How I Designed This This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/5knUr30CgIy