Over on the RepRap blog, [Rhys] has been experimenting with molten metal to build circuits with the RepRap.
Last June, [Rhys] found a neat alloy made of Tin, Bismuth, and a little bit of Indium that melts at around 130° C, and has just the right properties to be extruded with a standard RepRap setup. The results were encouraging, but the molten metal quickly dissolved the brass and aluminum nozzles [Rhys] was pushing liquid metal through.
The solution to this problem was solved by anodizing the heck out of a RepRap nozzle to make a hard, protective oxide layer. Already [Rhys] has logged hundreds of hours squirting molten metal out of his RepRap with no signs of any damage to the nozzle.
Since [Rhys] figured out how to print in metal, he whipped up an extremely minimal Sanguino board. You can see this RepRapped PCB running a LED blink program after the break. Now to work on the RepRap pick and place…