Metal printing idea

I just wanted to run this idea by, and see if it might be worth serious thought. Low temp alloys like Rose's metal or solder aren't good for extrusion because metal is runny, and doesn't have an ooze stage where it can be melted and hold some shape. What if instead it was used in dual extrusion. Use HIPS in the first extruder to lay down perimeters, then use the second extruder to pour in the metal as fill. When done, dissolve the HIPS to leave a metal object. In this case the fill is the print and the perimeters are a mold that is built and filled layer by layer.

This seems like it would work fine for building the walls of objects that are hollow. For solid objects, you could run solid rectilinear fill, where plastic skips every other line, creating gaps which get filled with metal. After the plastic is dissolved you would be left with a lattice of metal inside if you didn't want it to be solid. Fill percentage would be a matter of changing the ratio of plastic lines to metal.

It basically sounds like you use the HIPS as a mold.
The idea is not completely new and new technology would be mostly interesting if it were more efficient than existing tech. But the mold making industry is already very matured, the addition of 3D-printers and SSL (selective laser sintering) have helped making the moldmaking/casting business even more profitable for low quantities.

There is one technique for priting with metal which works very well, however it's very very dangerous, I forgot the name but I've seen images of injuries from that technique and they are not to be taken lightly..

Fun to think about, but it's very hard to achieve metal printing with good materials if you're a DIY'er

---

http://www.marinusdebeer.nl/

Quote
Ohmarinus
... Fun to think about, but it's very hard to achieve metal printing with good materials if you're a DIY'er

Ah! but 3D printing itself was just fun to think about until people started realizing that the expensive parts of 3D printers could be simplified to the point that plywood and glue could be used to make a 3D printer - which would then make somewhat better parts for the next printer.

Just thought on the basic idea. How about using ceramic 3D printing to make the mold? The metal used would then not be restricted to very low temperature alloys. The pouring of the metal could be done one layer at a time, as several layers, or on the completion of the mold.

Quote
IanJohnson
Low temp alloys like Rose's metal or solder aren't good for extrusion because metal is runny, and doesn't have an ooze stage where it can be melted and hold some shape.

You can make a low temp alloy that does have an "ooze stage", as described here.
You can also get decent results simply by putting off-the-shelf solder right into your printer, as described here.