With electroplating, you have to make the 3D part conductive. You also have to deal with wet chemistry and fumes. This process uses a rock tumbler, copper powder, and small ball bearings.

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 ...