If you're into the maker culture, or even somebody who's remotely familiar with technology trends, you know all about 3-D printing. That tech uses a spray nozzle to lay down layers of material and build objects in a process known as additive manufacturing. It's been used to fabricate everything from aircraft engine parts and furniture to entire buildings, plus an increasing assortment of odd projects such as selfie statues.
But if you've ever watched someone whittle a toy whistle from a piece of wood or engrave a design on a leather belt, you also know that it's possible to make something by taking away material as well as by adding it. Now, imagine doing that cutting and engraving with a 3-D printer that wields a laser beam instead of a spray nozzle, and you've got the concept of subtractive manufacturing.
This isn't a new idea, really — the earliest use of lasers for precision cutting dates actually back to the mid-1960s. But until recently, such machines cost tens of thousands of dollars, putting the technology out of reach for most craftspeople.
Now, though, a Seattle-based company called Glowforge is poised to change all that. Glowforge is offering an innovative wireless laser cutter/engraver, which works with design software on a desktop PC just like a 3-D printer would, but also stores plans and data in the cloud. The whole package could cost as little as $2,400.
"With Glowforge, you'll put a piece of material like leather, wood, or acrylic in the machine and it carves out your product using laser light," the company's website explains. "The technical name for the category of tools that includes Glowforge is a CNC laser cutter engraver, but that's a mouthful, so we call it a 3-D laser printer."
If you're thinking that sounds like a pretty cool gadget for your workshop, a lot of other people have the same inclination. Glowforge smashed the crowdfunding record for a tech startup in October 2015 when in less than 30 days it raised $27.9 million in pre-orders, including $2 million in less than 24 hours. Since then, Glowforge has run into some delays, which it says were caused by the need to do additional product testing. It now plans to ship its first machines in December 2016.
Steve Morris, a mechanical engineer and aerodynamics expert who has designed sailboats for the America's Cup competition and now runs Catylator Makerspace in Silver Spring, Maryland, explains that subtractive manufacturing with a laser cutter is significantly different from 3D printing. He says you wouldn't necessarily use it for the same sorts of jobs. "3D printing enables you to gradually build three-dimensional objects," he says. "A laser cutter is really more two-dimensional. You're starting with the material and cutting pieces out."
Morris jokingly likens subtractive manufacturing to the old aphorism about sculpture, that Michelangelo's David already was inside a block of marble, just waiting for the sculptor to free him.
But when it comes to shaping an object, Morris says, a laser cutter can produce much finer details than a 3-D printer. That's because a laser printer can make cuts that are a few thousandths of an inch across, much smaller than the amount of material that a 3D printer nozzle can squirt.
Get to work, tiny Michelangelos.