I’m more impressed by these.
I agree that your link is pretty awesome. I would like to correct the impression you inadvertently made: while the frame was aluminum, the entire shell, including the glass, was printed.
I also was interested when they were going to finally go into production. According to this article, they want to mass produce the Urbee 2 by 2015 (if that’s what they meant by ‘in 2 years’).
Another link showing the growing sturdiness of 3D-printed parts:
3D-Printed Rocket Parts Excel in NASA Tests.
Bonus points for mentioning 3D-printed pizza 
there is hype and bad journalism with this topic.
in recent months there was an article i read online (forgot where, no cite) that talked about how the supply problem for things like ammunition for troops fighting in remote locations could be solved by them having 3D printers.
So-called ‘3D printing’ is more of a grey area than a ‘revolution’. Three dimensional, computer controlled milling machines have been around for decades and are one of the primary reasons mass-produced items can be as sophisticated, compact, reliable, stylish-looking, and inexpensive all at the same time as they are. And computer controlled machining is basically the same thing as 3D printing, albeit one is additive and the other subtractive. Creating an additive 3D printer that can ‘print’ with metals as accurately & efficiently as a computer-controlled milling machine can ‘cut’ from blocks of them is going to be a challenge.
Ammunition is a terrible application for 3D printing. If you have the appropriate materials (lead or DU, whatever metal you use for the jacket, and whatever you use for the propellant), then ammunition is really easy to make even without a 3D printer. If you don’t have the appropriate materials, then it’s impossible to make it even with a 3D printer.
And another application of 3D printing is to use a low-durability material like wax or the like in the printer itself, and then use that for a lost-wax casting in the metal of your choice. It’s a little more expensive than printing your part directly, but it can also get you a lot more durability. I saw a video once of Jay Leno (or rather, mechanics working for him) using this technique to replace a small no-longer-manufactured part on one of his classic cars.
I think that post addresses the worst-case scenario, but there are lots of not-worst-case scenarios, too.
It’s a good point that if an object is poorly designed that a critical part is overstressed, replacing the broken part won’t help. And sure, some parts are going to need careful production – you can’t 3-D print a sword (at least with with the technology of now and the next couple decades), and probably can’t 3-D print a bicycle gear or some other high-stress application.
But most parts aren’t high performance/high-stress. Knobs, retaining clips that keep a cover on, plastic cases, etc. don’t need super-engineered materials; they just need whatever kind of plastic you have available.
Even in cases, such as gears, where the kind of plastic matters, you can probably get close enough with typical 3-D printer material. So the new gear wears out in five years instead of the ten years the original gear lasted, so what? That’s still better than junking the whole machine.
So there are lots and lots of cases where 3-D printing could be successful.
As far as the sprinkler piece goes, I don’t know enough about materials to know what would be the best material and chances of success; it looks pretty high-stress. But I think it’s worth finding someone who does know something about it (which at this point is probably anybody who actually has a 3-D printer) and, if they think it’s worth trying, go for it. I mean, it’s not thousands of dollars of material you need for that part, so all you will have lost is a little bit of time. I assume you’re doing this mostly for fun anyway, so the time probably isn’t a big deal.
Is there really a collector market for Vintage Nelson Dial A Rain sprinklers?
I suppose we could have said many of the same things about the Internet around 1992. It wasn’t really new, and it wasn’t really solving anything that couldn’t be solved some other way. The thing was, those “other ways” had been brought to their effectiveness peaks, and the Internet just kept building and building and building. By 1994, suddenly everything looked inevitable. But really, nothing had fundamentally changed. Computers were faster, modems were faster, and the infrastructure was more developed, but none of these things just popped out of nowhere in 1994.
I agree that the 3D-printing is not quite ready for prime-time. However, I get that same feeling that I had back in 1992; that feeling of a “new” technology charging from the backfields to overtake the existing reality. It seems like things are building towards a new kind of inevitability. It’s hard for me to see what’s going to stop it. I’m unaware of any fundamental stumbling blocks or theoretical limits. Now that there’s a fledgling mass market developing, it’s hard to see how development won’t, in fact, accelerate.
I also want to point out that there is a fundamental difference between additive and subtractive methods. Subtractive methods are somewhat limited in the types of objects they can create in at least two ways. You can generally only use one material; if you want two or more, you are going to have to join them somehow. You can not make objects inside of other objects; if you need to do this, you are going to have to make three parts, with parts A and B being somehow joined around part C. Additive methods can do both easily. There’s a third difference, but I’m not sure if it’s a true difference or just my imagination: additive methods seem much more conducive to putting manufacturing in the home. I’m not entirely certain where this strong gut feeling comes from, but it seems confirmed every time one of the little home 3d printer makers drops their price and raises the quality of objects made.
As for metals, it’s going to be awhile before the old methods are replaced. But if NASA produces steel parts for rockets using a type of additive method, then it’s not hard to imagine one niche market after another following suit until it’s not a niche market at all anymore. Here’s two interesting articles that I found just practicing my google-fu:
Article 1: NASA 3D prints rocket parts — with steel, not plastic
Article 2: 3D-Printing Liquid Metal Could Make the T-1000 Terminator a Reality (Ignore the sensationalist title; check out the video for some interesting examples)