My biggest issue with this is that your produced filament will have garbage tolerances, probably some air pockets, and have a high likelihood of jamming your ho

My biggest issue with this is that your produced filament will have garbage tolerances, probably some air pockets, and have a high likelihood of jamming your hotend at some point. A better solution would be a machine that snips different color filaments right off the spools at the right lengths and welds them together. That all said, this is a cool project from a "what's possible" perspective.