This spool holder has seen some miles in the last year and I noticed it had cracked and miraculously still holding on! So I went back to the drawing board! I had originally found this on thingiverse.com but I redesigned for narrower spools. (I can’t help myself, I have to tweak everything somehow!)
In this new design I shortened the height, overlapping the weak spot and helping in printing. The first design used a lot of support and I have a hard time printing curved bottoms due to the overhang. Now that it prints flat to the bed then angles up the print is stronger and prints faster!