Filament spool holder

I've found that with the 2kg (~4 pounds?) spools the regular filament holder of my ender 3 failed significantly because of the weight on the frame and the amount of friction between the spool and the rod it should slide on. Because of that, I've come up with this design - a simple two-legged spool holder utilizing two 7x22mm ball bearings. Simply hammer them inside the main rod and then push the roll ends inside. Tall enough to fit a 2kg spool (although I guess you could put some books under eac