Illustration by Anna Minzhulina.

I ask Brendan Dawes, a web designer based in Manchester, to explain how it works: how he can download a file and, two hours later, hold a white rabbit figurine in his hands.  

“You download it off of Thingiverse,” he says, “and you get the STL file. You load that through ReplicatorG and generate the G code, which tells it to go to certain corners. Then you press the button that generates the code, and then you either run it straight from ReplicatorG or download it to an SD card, put it in the MakerBot…” 

Dawes is English as English gets, but as he describes this process I’m sure he’s speaking another language. In fact, he’s just using open-source 3D-printing lingo. 3D printers are machines that use models of objects rendered in code to create physical items you can touch. Dawes’ own 3D printer takes a spool of raw plastic filament, melts it down like a hot glue gun and extrudes the plastic according to a digital blueprint to make, say, a shower-curtain hook or a working pair of pliers. 

But personal 3D printers can do more than just produce knick-knacks for nerds. Last September, KingLudd, a user on the online database Thingiverse.com, posted a digital design for the lower receiver of an AR-15. KingLudd had theoretically made it possible for anyone with access to a 3D printer to assemble a semiautomatic rifle; all the other parts of the gun could be purchased without a permit. 

The episode made waves on tech blogs and forums, and the creators of Thingiverse asked their users to weigh in on whether the design should be classified as a deadly weapon and taken down. It was a robust debate, reminiscent of the early days of file sharing, when the issues at hand were steeped in moral conflict but the law lacked an updated vocabulary. Ultimately, there’s little overlap between 3D-printing enthusiasts and gun nuts. But the possibilities were clear. Today, digital technology makes it easy to disseminate cookbooks, comics and classical music; tomorrow, musical instruments, measuring spoons and machine guns. 

Commercial 3D printers have been around for years, but, today, interest in home-assembled machines is growing. Open-source hardware and software—which anyone can freely use or adapt—has allowed hundreds, if not thousands, of engineers and programmers to create and sell their own devices, while editable blueprints make it possible to create countless objects. There is now a worldwide “maker” movement of do-it-yourself 3D-printing enthusiasts, documenting their efforts on wikis and in sprawling forums. By leveraging open-source development, these curious geniuses have figured out how to assemble quality printers for less than $1,000. 

Charles Hull, an American inventor with some eighty-one patents to his name, filed the first patent for 3D-printing technology in 1986. The process he designed uses a UV laser beam to shape liquid polymer plastic into a finished object, layer by layer. Variations on this method have emerged in the decades since. Today, modeling software can render a 3D image in horizontal plastic slices as thin as a tenth of a millimetre each, and designers, scientists and architects regularly use commercial 3D printing to test their ideas off-screen. Instead of sending a design elsewhere to be made into a model, those with 3D printers can quickly create and tweak their own prototypes, using anything from brittle plaster to plastic to glass. 

This technology has made it possible to create objects in novel ways; with almost any other manufacturing process, it would be impossible, for example, to make a hollow sphere without joining two halves together. The potential applications go beyond small trinkets. In 2010, the Winnipeg-based company KOR EcoLogic introduced the world’s first 3D-printed car, the Urbee. NASA is currently developing technology for astronauts to print spare parts in space. 

This is all remarkable, but also remarkably expensive. A commercial 3D printer, about the size of a photocopier, is worth a small fortune; some recent machines cost anywhere from $14,900 to $34,900 US. That’s why the DIY 3D-printing community relies on free, editable code for creating and disseminating the technology. Enthusiasts can then buy the parts and build the machines themselves, IKEA-style. 

Cheap, home-assembled printers are getting faster, better and more popular. There’s a variety of options on the market: a UK invention called the RepRap, a Cornell University machine called Fab@Home and a robust Dutch speed demon known as Ultimaker. But the most successful is probably the MakerBot, the machine that Brendan Dawes uses. If there’s one company and one machine that will give 3D printing mass-market appeal, it’s this one.

MakerBots are made in Brooklyn. At first glance, the device looks like a wooden toy, no bigger than a microwave. Each of its four walls has a window, which lends it the aura of a showcase. When it’s printing, you can see a tiny internal computer get to work. The printer will heat up, pull the filament and start squeezing out the heated plastic. The whole process smells pretty bad—as Dawes puts it, “Oh God, you have to have a window open.” He adds that the MakerBot creaks and whines in a way that’s unusual for twenty-first-century technology. “There’s something very analog about it, even though it’s driven by digital technology inside.” 

Because most home 3D printers need to be put together by the customer, they remain in what Dawes calls “hardcore geek territory.” But MakerBots can be purchased fully assembled and ready to use, no nerdy know-how required. The company’s business has grown dramatically since it was founded three years ago. In 2009, MakerBot catered mainly to programmers, selling just twenty kits a month at a retail price of $1,099 US. By the end of 2011, that number had jumped to three hundred a month. 

“The majority of people who get MakerBots are ordinary people who want to live in the future,” says Bre Pettis, CEO of MakerBot Industries. Pettis is Ira Glass meets Bill Nye: earnest, bespectacled and fortysomething, with a head of salt-and-pepper hair. As the public face of the company, he preaches its gospel: owning a 3D printer “could possibly save your life,” he says, because you can create almost anything on demand. MakerBot has shipped machines around the world, and Pettis contends that the technology could revolutionize the economics of manufacturing. Instead of buying things, thousands of people are starting to print them. Of course, Pettis’ bullish attitude helps pay the bills at MakerBot—and not everyone in the maker community shares his fervour.

The Vancouver Community Laboratory is a dusty space filled with dystopic sculptures and futuristic machines. Wood and metal are twisted into freakish bicycles, and abstract carvings litter the floor. In the middle of the room sit three steampunk-Tinkertoy constructions: RepRap printers made by Wade Bortz. Bortz, a mechanical engineer and a major figure in the DIY 3D-printing world, is one of twenty-one international core developers for RepRap, a printer that’s designed to copy itself; the machine can print most of its parts, aside from steel rods and electronics, in a day or two. In 2008, Bortz became the first person to replicate the RepRap “in the wild”—that is, out of RepRap’s UK lab. 

Bortz built his first printer—a metal cage, about two feet high, with rainbow wires twisting in every direction—in the kitchen of his tiny Toronto apartment. “I thought it was totally amazing,” he recalls. “I was so excited. I spent all night working on it because it was so different. At the beginning I had very high expectations. I thought, Wow, this is going to change the world.” 

A few years later, he’s less convinced. Most amateurs involved with 3D printing are interested in playing, not transforming manufacturing overnight. “Very few people are using these things for professional applications,” Bortz explains. “It’s mostly for fun, to build toy cars and that stuff.” DIY 3D printers have to move past the trinket phase in order to gain more users; in Bortz’s opinion, the machines will need to be able to create products that compare with the quality of factory-made goods. When printers can produce electronics on the go—a very real possibility—Bortz says he might renew his belief. It isn’t that 3D printing isn’t improving—it’s just happening more slowly than he once thought it would. 

For every DIY 3D-printing evangelist like Pettis, there’s a more conservative Bortz, unsure that the revolution is imminent. Still, despite divergent expectations, the two men are motivated by a shared spirit: the technology fascinates them. For many makers, whether home 3D printing ever becomes widespread is beside the point. The idea that you can use computers to print physical objects or create self-replicating robots offers its own rewards. Some scientists simply like to innovate. 

“Right now, if you built and put a 3D printer in everyone’s basement, no one would be able to use them or have a reason to use them,” says Sam Bayless, a PhD candidate in computer science at the University of British Columbia. “Thirty years ago, if you said that everyone will have a personal computer and everyone will carry computers in their pockets, unless you were talking to Isaac Asimov, you would have been laughed out of the room.” Nonetheless, a group of geeks plugged away, making faster machines and smaller chips. Now, almost every secretary, every reporter, every CEO uses a computer all day long. And that, Bayless says, “That’s amazing.”