I read an interesting column today about the future of 3D printing. The author gave the caveat, "I don't fully understand them, so they seem like magic sent to us from the future by Captain Picard." Which probably explains why, while she pointed out some of the many awesome things that 3D printing could do, she may be overselling them a bit, and her predictions for where things will go are, at best, a little naive.
For my own part, I'm largely unfamiliar with the technologies of 3D printers. I've heard some reports of things that they've done, and last year I got to visit two different R&D labs that were exploring the capabilities of the technology. The first was at NASA's Marshall Space Flight Center (probably the same group of people responsible for this). The second, a couple of months later, was at Gulfstream's Savannah facility (probably related to this educational program, but definitely not the same place). I got to see, first hand, some of the remarkable things that they could do (my favorite: a chess set with rooks that had a spiral staircase going up inside them). 3D printing allows for some amazing things that are simply not possible with other manufacturing techniques.
It's also got a lot of potential as a cost-effective way to do single-item or other low-quantity manufacturing. This is normally touted as a way to go about prototyping. But in my professional environment (buying parts for old systems that require from a few replacements a year to one every few years), this could be a silver bullet against obsolescence (or at least it can be once we redesign everything for the technology). 3D printing is a big deal.
Ms. Kohn hits on a number of major accomplishments of 3D printing. The biggest, arguably, is the ability to print body parts. This is about the closest that we've come to being able to play god, and if the technology can mature sufficiently, it could provide an ethical alternative to the old idea of cloning yourself to create a spare part factory (an idea that was only floated around to show some of the morally reprehensible applications of human cloning).
Her other ideas are interesting, but basically non-starters. Sure, you can print houses, food, and toothbrushes. But most people never would, because it would be a pointless waste of money.
Think of your traditional printer. It gives you the technology to publish your own books. But does Amazon give you a file that sends the book you just bought to your printer? No! It's far cheaper to mass produce those things, store them in warehouses, move them around, and deliver them to your door than it is to buy the paper and toner for your inkjet. Desktop publishing is fantastic, but for anything more than a few copies or a few pages, it's far too expensive.
3D printing has the same problem. Even if the 3D equivalent of "ink cartridges" go way down in price (like 2D ink never has done), it's still going to be far more expensive than just producing most of these things the old-fashioned way.
With any luck, 3D printing will be a significant part of the future. And it will solve a lot of problems. But it won't solve all of them.