today is Sep 28, 2022

It may sound like a pop band, but μ-WAAM is actually a 3D printing technique for making small metal parts from the NOVA University Lisbon. Of course, WAAM stands for wire arc additive manufacturing, a well-known technique for 3D printing in metal. The difference? The new technique uses 250 μm wire stock instead of the 1mm or thicker wires used in conventional WAAM.

The thinner feed wire allows μ-WAAM to create fine details like thin walls that would be difficult to replicate with traditional methods. Typically, for fine structures, printers use fused metal powder. This is good for fine details, but typically slower and has higher waste than wire-based systems.

What we found most interesting is that the printer looks more or less like a conventional 3D printer with a special extruder that handles the fine metal filament. Of course, instead of heat, a 12V 100 aH battery provides an arc. Oh, there’s also an argon shield gas system to keep everything working well and prevent defects.

Still, this looked like something you could reasonably attempt to build yourself. The wire feeds through a conventional brass nozzle. The arc system and the associated shield gas would be the only big modifications, it seems.

Of course, finer wire means the prints are not as fast as a normal WAAM system. A powder system might deposit 2 grams of metal per minute, but μ-WAAM did about 5 grams. Of course, with fatter wire, a real WAAM system might reach over 18 grams/minute, but will not be nearly as precise.

We’ve followed [Metal Matter’s] homebrew metal 3D printing efforts for some time. You can see a video below of his system that also uses fine wire, but uses a laser instead of an arc. We’ve also seen fused powder done with a laser cutter. If you build something that works — or even something that doesn’t be sure to let us know.