Cheap 3D printer with steel

Academia.edu: From the Register:

The one thing that made 3D printed guns tolerable to the non-gun-owning
community was that they were made of plastic, because metal 3D printers
were costly. Now, a bunch of scientists from Michigan Tech are showing
off a cheap 3D printer that fabricates in metal.
Metal 3D printing isn't new, but it's been expensive until now. The
open-source Michigan project, here, offers a bill of materials costing
just under  1,200 to build the 3D printer, controlled by a Linux
computer.