608 bearing pulley

A pulley uses 1 x 608 ball bearing. You can use it with 1..6 mm rope. I thing it's good idea to make universal filament spool holder with 2 8 mm horizontal pins or shafts and 4 pulleys for each filament spool. It is actual if you have a lot of filament spools in line.
WARNING! You must to pause the printing and drop the bearing.