If you have a 3D printer, your nozzle and heater block are invariably covered in a weird goo consisting of decomposed and burnt plastic. There’s only one way around this – a nozzle sock ...

You don’t think of hobby-grade 3D printing as a good method for creating rocket nozzles. But [Mister Highball] managed to create a copper nozzle using a common printer, a kiln, and some special ...