The Trash Printer
The Trash Printer is an open-source, low-cost, large-format 3D printer that prints directly from shredded plastic trash instead of filament.
It has been tested to work with shredded Polypropylene (#5) and Polyethylene (#2 and #4) which together make up over 50% of all household plastic waste. It uses a 1/4" (4.5mm) nozzle, which makes it VERY tolerant of dirt, labels, and adhesives, which are common in post-consumer waste streams.
The parts it makes are incredibly strong, light, and flexible, more comparable in terms of strength to parts made by traditional injection molding processes than those made by most desktop 3D printers. The better you clean your material, the better your prints will look, but if you're lazy like me, you can just throw your trash in without even cleaning it first. Skipping the filament-making step entirely reduces the recycling process to just two steps: Shred, and Print.
Latest Stable Release
The Trash Printer has been in development for several years, but the most recent release, Version 3, is the first version to be fully open-source, and is easier and cheaper to build than the previous versions. This repository will be the home for the development of V3 onwards.