They don’t think hobby-quality 3D printing is a good way to make rocket nozzles. But [Mister Highball] managed to make a copper nozzle using an ordinary printer, a furnace and a special filament containing copper.
The copper thread consists of around 90% metal. Virtual Foundry recommends preheating it before printing and you’ll need to sinter it in an oven to remove the plastic and leave a solid piece of metal that will naturally shrink.
The results weren’t great at first, but the final run looked pretty good. You should follow all the advice on using the filament as it is quite a bit more expensive than regular PLA. There are clearly some very specific steps that you need to follow in order to get good results.
Of course, you’ll also need a furnace and the other equipment you need to handle molten metal. While it’s impressive that you can make a metal part so easily, it’s still not as easy as a regular print and it’s not much easier than simply casting the part using a lost PLA technique.
While 3D printing rocket parts isn’t a new idea, previous efforts didn’t use cheap FDM printers. We are excited to have a real metal 3D printer one day.