The original Tinkeriffic Spool Spindle (of 2012 vintage) functioned adequately, but was never a baby's-butt-smooth solution to my filament feeding fiascoes. This three-part solution (thirteen parts, if one counts the 4.5mm BB's (http://bit.ly/1ngex61) is designed to use a Tinkertoy rod as an axle and is a much, much smoother ride for your filament spools. I found inserting BB's into the original 608 bearing to be frustrating so I split the bearing in two and left it to the end user to super glue the parts together.