Making homemade guns on a 3-D printer becomes real, so engineering expert suggests stronger laws on gunpowder

Laws mean little if a determined criminal or a hobbyist teen wants to make plastic guns or extra-high capacity magazines, says Hod Lipson, Cornell University professor of engineering and a pioneer in 3-D printing.

"With a homemade 3-D printer, you can print a gun using ABS plastic, the same material that LEGOS are made out of. You can even use nylon, and that's pretty tough," he says. "You won't be able to make a sniper rifle with a 3-D printer and it won't shoot 10 rounds a second, but the gun you can make could be dangerous. And a high-capacity magazine is nothing more than a strong plastic box with a spring. It's trivial to print."

Lipson and co-author Melba Kurman just published a new book, "Fabricated: The promise and peril of a machine that can make (almost) anything." (Wiley, 2013.) The book includes a chapter on "3-D printing and the law," which addresses the legal and ethical challenges raised by 3-D printed firearms. The book also explores 3-D printing's impact on consumer safety, intellectual property, and ethics.

As Lipson and Kurman detail, three-dimensional printers are intended to do the world good. In industry, 3-D printers can make hard-to-find spare parts and complex new devices. Researchers are developing techniques to 3-D print tailored and personalized body parts like heart valves. 3-D printers can even make food.

Lipson explains that on the Internet, there are blueprints and designs available to 3-D print guns. As an engineer, he's seen dubious rogue designs online. "Some designs are not safe," he says. "More than criminals, I am worried about innocent kids making guns and injuring themselves. What happens if the design is faulty or if the plastic was printed at the wrong temperature, rendering the gun weak? When fired, it could blow up in its user's face. All kinds of parameters go into making 3-D objects and when you introduce an explosive such as gunpowder, that's when things can go wrong," Lipson says. The small footprint of new personal-scale manufacturing systems also makes it easier to fabricate firearms more discreetly than before.

Lipson agrees that a more effective gun control solution worth exploring might impose legal limitations on gunpowder rather than gun parts and accessories such as magazines.

Says Lipson: "If I were talking to lawmakers, I would encourage them to address the most basic part of a firearm -- the energy source. You must have gunpowder to fire a weapon. The law could regulate the explosives. To fire a bullet, you need high-energy propellant like gunpowder. After all, 3-D printed and arbitrarily shaped plastic firearms are going to be increasingly hard to detect using traditional screening techniques. A high-capacity magazine might look like something else. It may be more effective to control the gunpowder."