very cool project. They have converted an old CNC router table into a FDM 3D printer.
They are using a industrial shredder to convert old milk jugs into HDPE chips. They are then fed into a hopper and a drill and auger bit push them into a custom extruder heater body.
While most RepRap sized printers use a 0.5mm nozzle this printer is using a 6mm nozzle. This size is needed to have reasonable print speeds. They initially plan to print a boat (for a milk carton derby?) and are looking for feedback on what they should print next.
I think 3D scans of people printed life size could be very cool. Maybe this would be an interesting thing to print...