One of the limitations of 3D printing is in the materials—plastic might be the most affordable and widely available, but it's also cheap and brittle. So some students at Michigan Tech University have made a relatively cheap metal 3D printer, and they're releasing the plans to the masses.
The team's printer was cobbled together for under $1,500. It required a small commercial MIG welder and an open-source microcontroller to lay down thin sheets of metal on top of one another to create jewelry-like objects in little geometric shapes (see left).
Now, this 3D printer might be cheaper than a MakerBot Replicator 2, but it's also a hell of a lot more dangerous. So it's something that's intended for a skilled metalworker or perhaps a machinist, rather than your standard basic 3D printing hobbyist. Think more an aid group in Haiti 3D printing medical supplies or a small manufacturing outfit than your weird neighbor 3D printing holiday ornaments.