Stackable Filament Holder with fully printable parts

Here's my #FilamentChallenge. I wanted this to be print-and-play so even the bearings in the tube are 3D printed in place. Use the mid-beams to stack holders laterally and the puzzle-piece base allows fore and aft stacking (the multiple guide holes allow for guided back row spools). I'll add clips to pinch spool filaments that aren't being used.

This is one of my first designs with AutoDesk Inventor so I'd love advice or constructive criticism. Even with the base separated in half, the bottom piece is still just out of my printer's range, but I have printed the remaining pieces and they work fine. I'll add an adapter for the 53mm spools. I made this mostly for the challenge since I'm out of filament, but I think it could work well for many different printers.

Let me know if I should change anything or add specific adapters, thanks.

The only challenging print is the tube, which is composed of 3 pieces that must be printed together. I printed this piece with ABS at 60% with external supports and no shells. Use the version with shifted bearings - they sit on the bottom of their well instead of the center. Once printed, remove all supporting structure and gently twist the two tubes against each other to break the bearings loose. You can also squirt some acetone into the bearings to help shape them. I'll try to help if anyone wants to make one, good luck!