Yeah, you're right. The word translated as 'stone' also can mean 'hard object, metal, rock', and refers here to plastic object - so the 3d printer is somehow a

Yeah, you're right. The word translated as 'stone' also can mean 'hard object, metal, rock', and refers here to plastic object - so the 3d printer is somehow a "hard-object device". Doesn't make much sense without the link to a video to provide context! (Welcome to Toki Pona, where often things make no sense out-of-context... ).