Treat this person like you would anyone else in the class. If they behave badly, tell them to stop. If they continue, throw them out. Otherwise, let them learn as much as they can, just like the other students.
Well, several show up when I googled for 3d plaster printer. Mostly they look like places where you send them the object file and they print it for you, but you could get the same kind of machine that they use.