Via Gizmag:
The Mx3D-Metal robot is part printer, part welder. It can sculpt remarkable, gravity-defying designs using a variety of metals, including steel, stainless steel, aluminum, bronze and copper, without the need for any other means of support. “By adding small amounts of molten metal at a time, we are able to print lines in mid air,” explains Laarman on his website.
Click the link to see more: 3D-printing robot creates freestanding metal structures