SpoolHolder Rolling Bar Holding parts (for MMU Classic vacuum-formed spoolholder)

I made parts to hold the rolling bars on the spool holder.(Remixed PTFE-holder-VAC-R3.stl )

The rolling bars of MMU's Classic vacuum-formed spoolholder are not fixed and can easily fall off. (That's annoying.)
These are parts to hold rolling bars.
(To be precise, they hold ball bearings.)
STL files and gcode data for printing are available for 1 piece and 4 pieces. 
4 pieces set is added "x4" its file name.

(Remixed PTFE-holder-VAC-R3.stl ) 

I made parts to hold the rolling bars on the vacuum-formed spool holder.
(To be precise, they hold ball bearings.)

(Remixed PTFE-holder-VAC-R3.stl )