This is for a Hypercube Evolution with 3030 extrusion. There are multiple options for holding the filament. You can use the regular arm or longer arm and closed nut cap. Or you can print the 8mm rod plug and use a 8mm threaded rod and nuts with your choice of bearing spools. I have found the plug option to have a little sag with a full roll. Nothing that I fear will break but you may want to up infil for that option on the base. This holder sits inside by 40mm. That is 40mm from the inside edge of the extrusion to the back edge of the holder. My printer has aprox 50mm of room so no danger of it clearing.

on the rod version I used https://www.thingiverse.com/thing:969358 for the quick release lock and I used https://www.thingiverse.com/thing:480167 for the bearing spool holders.