Unless you are changing filament VERY frequently, the energy costs will almost guaranteed erase any environmental benefits from filament waste.
Because you basically have the exact same problem that most of the filament reuse methods have: If you want a good connection, you want to have both the filament coming out of the nozzle AND the end of the filament you are printing onto to be hot. That is a LOT of engineering effort as you would likely need to keep the current tail of the output filament hot for the majority of the print so as to not add significant stalls when you change filament. This is why most of the tools to fuse to strands have that sleeve that you heat up
Because the moment you start adding supports for your output filament? Holy crap.
I dunno. I still think the answer is more cost effective recycling facilities. I’ve enjoyed Stefan’s various attempts to reuse filament but outside of the splicing methods for near empty spools, they are all a giant mess requiring multiple tools for an often subpar result. Just standardize a cheap and effective way to throw our poop, failed builds, and near empty spools into a box and send it to a filament company. Then give us a discount for doing so. And let said company use their industrial machines to reuse that plastic.
One other complexity: Again, unless you are changing materials constantly AND doing a super long print, the amount of filament you print during any given print is going to be minimal. So you need to maintain state on the build plate/apparatus in between potentially months of prints.
Oooh, manyfold looks like exactly what I want. Thanks