A spool holder that uses the original metal bracket that comes with the Ender 3 (or CR-10) and adds bearings to minimize friction.
My Ender 3 came without the tube for the spool holder, so I got creative.
Uses 4x MR105-ZZ bearings.
Support is only needed on the main part inside the pockets for the bearings (i set my overhang angle to 70).
The nuts do not need support, if the threads come out unusable try a smaller layer height to improve overhangs.
I printed mine at 0.3mm layer height to save time.