Spool holder with two 6804 bearings: a simple and efficient design that's easy to print. The angled body prevents the spool from slipping off, always guiding it toward the center. You’ll need two 6804 bearings (20mm x 32mm x 7mm) and a drop of glue to secure them on the rod.

My one printed with PET-G, 0.3 height, 0.6 width, 120 speed on Ender 3S1