I added a hole for an M4 threaded insert to the main base part that attaches to the top of the Z-Axis. Planning on making a filament clip & guide to go here for each spool.
Also, I didn't want to have to use so many small pieces for the bearing axles, so I created a single piece, removable axle with a flange on one end and a space for an M4 threaded insert on the other. Now the rollers can be swapped or removed easily. This could also replace the two hollow rods from the original that serve as the front and back guide rails.
The author remixed this model.
I added a dedicated cutout in the base part for an M4 threaded insert as well as a redesigned single-piece axle rod.