TUSH - with reel stability

[I have updated this design. Use this instead: https://www.thingiverse.com/thing:2521463]

I found that using the original TUSH, my filament spool would sometimes ride in the gap between the bearing and plastic. By adding the side pieces the spool now rides down the center of the bearing edge. An additional advantage now is that the TUSH pieces don't move around as much either.