Loose screw? 3-D printer may soon forge you a new one

Pearce's device is something of a fire hazard, a side effect of the high temperatures needed to melt steel.

It may cost a million bucks or more to 3-D print yourself a real metal handgun, but if all you need is a specialty washer or custom gear, a prototype device made by Michigan Technological University may let you do so for a fraction of the cost. Want one? You can build it yourself with off-the-shelf parts.

"This technology provides a clear path to enable distributed manufacturing of custom metal parts," wrote lead researcher Joshua Pearce in an email to NBC News. It's mainly a proof of concept, but by being open about all the details, the team hopes others will tinker with the design and improve it.

The system is based on the existing "RepRap" type of 3-D printer. RepRap printers are totally open-source, meaning everything about how to make and operate them is provided for free — half the parts can even be 3-D printed themselves.

"As we were able to stand on the shoulders of giants we were able to develop the metal 3-D printer much faster than if we started from scratch," wrote Pearce. "This is clearly just the beginning of low-cost direct metal printing."

Another view of the printer in action shows the metal being laid down.

By building on the RepRap system, Pearce wouldn't have to worry as much about software to run his printer, what kind of 3-D model it would use, and so on. Of course, the fact that it prints using metal instead of plastic meant some serious changes had to be made.

Like other printers, Pearce's machine lays down thin layers of material in a pattern, waiting for it to solidify before putting down more. Plastic is easier to work with, since it melts easily and cools quickly. Using real steel welding wire as raw material means the temperature has to be higher and there are numerous risks added: spatter of molten metal, sparks flying everywhere, and so on. It's for this reason that Pearce recommends the device be located in a shop or garage — with fire extinguisher close at hand.

The quality, to look at it, isn't much to write home about, considering what we've seen recently in the field of 3-D printers, from high-resolution plastic models to printing out all the parts of a working handgun. But bear in mind that this is the first device of its kind, and it costs a fraction of a percent of industrial-level metal printers: all the parts can be bought for around $1,200.

"Small businesses will finally have access to metal prototyping and small batch production of 3-D printed products," Pearce explained. "Second, the developing world can use the printers to fabricate appropriate technology for sustainable development at extremely low cost."

"Finally, scientists will be able to digitally fabricate metal components of low-cost scientific equipment, making 'open source labs' in every field."

The 3-D model to be printed, and the result. Not exactly picture-perfect, but nor is it bad for a first attempt.

The first results may look a bit lumpy, but all printed-metal parts need finishing, and with a bit of work, the device will improve as quickly as its plastic-printing brethren. And since it's steel you're using, there's no need to worry about the end product snapping or chipping.

The team is already making changes to increase resolution and decrease print time. In a year or two the MTU device may be considered a watershed moment in the 3-D printing world.

Pearce is hopeful we'll use this power responsibly:

"Truly distributed manufacturing could finally put scarcity based economic systems behind us — providing enormous wealth for everyone while decreasing our environmental destruction. It is my hope we start making better choices with our advanced technological prowess — it is long past time."

The project's page describes the new printer and the process of using it, and the team's paper appeared in the open journal IEEE Discovery shortly; you can also read or download it

Devin Coldewey is a contributing writer for NBC News Digital. His personal website is