I moved my spool holder to the top of my CR6, because I upgraded to Direct Drive.  When using TPU, I noticed that the filament did not feed very well on the stock spool holder.  I designed and printed this one, and it is working great so far.

I used these bearings:  uxcell FR8-2RS Flange Ball Bearing 1/2"x1-1/8"x5/16" Shielded Chrome Bearings 4pcs: Amazon.com: Industrial & Scientific from Amazon.

The bearings were a press fit in the roller shell.  Install the keeper using a 3mm x 8mm machine screw, it will self-tap into the mount.  

Print the mount using a high infill and 4 walls for strength. I printed this piece using supports everywhere, twist part down.  Light supports (8% support in Cura) are all that is needed. 

The mount is a tight fit in the stock arm.  I had to use pliers to rotate it, but it has held up nicely.