I got a heart attack every time the spool holder and the spool made noise; it felt like something was going to break.

I saw spool holders with ball bearings online... but the bearings I had weren't correct. So, I redesigned one myself.

I'm not sure what orientation is best, but personally, I printed it so that the layer lines would bear weight instead of snapping.

Bearing

no clue what the model number is, but it should be 688-2RS Sealed Miniature Ball Bearings inner dia.: 8mm outer dia.: 16mm height: 5mm

Notes

If the tolerances aren't correct, feel free to edit the Fusion file attached to match your needs. My tolerances are very large so that everything would fit together a bit loosely (so that I don't have to reprint).