The 3-D printer craze has taken off with everyone from hobbyists and amateur gunsmiths to giant corporations. Less known is how the U.S. military has caught the desktop manufacturing bug too, and is designing printable components for bomb detectors and prototype limbs. Even more radical: The Army has even gone so far to deploy a helicopter-borne 3D-printing laboratory to Afghanistan.

All of these experiments are a realization by the Pentagon that the direct digital manufacturing is developing rapidly. For the Army, work with additive manufacturing work been taken up by the Research, Development and Engineering Command and the Army's Edgewood Chemical Biological Center (ECBC), the Army's center for research on defending against a toxic attack. At Edgewood, researchers work in a lab with a number of high-end printers, and are designing printable holders for the military's Minehound bomb detectors. The Army also recently revealed the center is preparing to produce thousands of the holders – which are designed to take weight off soldiers' backs – and do so relatively quickly.

"The fact that we could do this many designs and print them out and have them in their hands in one week gave [the Army] the option to choose between what works best for their application," Rick Moore, chief of the ECBC's Rapid Technologies Branch, said in a recent press release. "This is a good example of how we use the technology every day."

Aside from building bomb detectors, the Army also touted the idea of using the printers to scan soldiers into a 3-D model before they deploy to a battlefield. "This would ensure all physical features are on file," the Army release unnervingly stated. The plan is to make it easier for the Army to build a prosthesis for a missing limb that's "exactly how the soldier used to look – instead of sculpting it and scanning it," Moore said.

Moving into even more radical territory, the Navy has fielded interest in developing swarms of micro-robots to print and assemble objects on their own. Last year, the U.S. Special Operations Command sought a 3-D printer to do who knows what. 3-D printers are used at Sheppard Air Force base to make training mock-ups of drones. Boeing's Phantom Works defense geeks are also using the printers (seen above) to build prototypes for aircraft components. And in July, the Army deployed its first mobile 3-D printing laboratory to Afghanistan inside a shipping container capable of being carried by helicopter. The Army plans to deploy another lab to Afghanistan this fall while a third lab stays stateside.

In September, the U.S. Army Medical Command announced a solicitation that sought to buy a 3-D printer for the Walter Reed National Military Medical Center. The purpose was to use a printer to "fabricate pre-surgical physical models" as well as "guides, templates, custom implants, rehabilitation devices, anatomical models with segmented anatomical features," among other uses. Another recent solicitation sought a printer to be used for Army dentistry. The Army didn't go into details, but the printers are likely to be used for making dental prosthetics, an already common practice in medical offices.

It's not hard to see why the Army wants them. On the low-end, the machines can be bought for a several hundred – or thousand – dollars depending on the capabilities. But give it a few more years and the machines will likely become a lot cheaper. 3-D printers have been used to build objects ranging from silverware and LEGO-like toy kits to Warhammer miniatures. But to print professional-grade materials, a printer could set you back several tens or even hundreds of thousands of dollars. Those printers have been used to make portable oxygen generators, helicopter parts, concept cars and exoskeletons.

Hobbyists in the civilian world have been in an arms race to develop the first weapon made entirely of 3-D printed materials. But these have been attempted with relatively low-cost machines. At Edgewood, the Army's researchers are working with higher-end machines like the Objet Connex 500 and new stereolithography (SLA) printers like the SLA Viper 7000.

The older printers – and the kind most frequently used by hobbyists – use heat to harden layers of printed liquid plastic into a complete model. But that also means that a finished object can appear a little melted and smudgy. The SLA machines are much better, print at much higher resolutions and use UV light instead of heat. The machines can also use a wider variety of materials and print at higher speeds. The problem is that these machines and their ultra-thin light-sensitive plastic are prohibitively expensive for most consumers – for now.

Besides the more far-out ideas from the military, the wider adoption of the machines is driven mainly by practicality. Time is money in manufacturing, and being able to build a prototype within hours as opposed to days – or a piece of equipment in days as opposed to weeks – saves on both. But if the Army is now printing components for bomb detectors, which could conceivably be printed in battlefield laboratories as well, it may only a matter of time before the military's forward bases start resembling mini-factories.

On the other hand, lowering costs for military hardware could benefit an insurgent force as much as the Pentagon given a long enough timeline. Printing bomb detectors could give soldiers an advantage. Not so much is the other side is using the machines to mass-produce the bombs.