In practice, we're finding that PLA is too fragile, users are happy with ABS, and Nylon is indestructible.

As for "in the same price range" you can print a hand, and buy all of the bolts and lines, etc., for under $50. Commercial prosthetics are $10-50K. Volunteers and 3D printing is _much_ cheaper.

Using traditional manufacturing, prosthetics really ARE very expensive. Remember, they have to manufacture all of the parts in a range of sizes and designs to fit everyone, someone has to come spend time with the patient to fit it, etc. And that's great for people who can pay $10-50K for a prosthetic.

e-NABLE and Robohand's approach is to replace the expensive manufacturing/stocking process with 3D printing, so you can print just what you need when you need it. And instead of professional designers and doctors getting paid, we're all volunteers (often professionals, but donating time).

If you want to help with enabling people to 3D print prosthetics at home, a group actively working on it is e-NABLE (http://enablingthefuture.org). There are numerous open source designs, and lots of people using them and providing feedback. We have Google Hangouts (https://plus.google.com/u/1/communities/102497715636887179986) on various topics several times a week (there's an R&D group working on the mechanisms, there's a group building a web site so that people can put in their measurements and get parts out scaled to exactly fit them, etc.). There are 600+ people in the community now, and there are tons of projects that people can contribute to. There's a map of volunteers (http://www.zeemaps.com/pub?group=609826&legend=1&geosearch=1&search=1&locate=1&list=1&shuttered=1&add=1) so if you need a hand, or you want to help others print parts, etc., you can find volunteers near you.

Actually, 3D printing in wax is routine in jewelry and dentistry, because it's a great material for casting. It's not a consumer technology, so it's not covered in the mainstream press, but those guys LOVE 3D printing. The machines are $5K and up, as they're sold as a business/industrial product, not consumer.

For the home 3D printers, it's quite common to use the "lost wax" method, but using PLA instead of wax.

We're making a lot of progress on that front - there are many people using 3D printed prosthetics in daily use now, and extremely happy with them. (http://enablingthefuture.org has tons of pics). And as 3D printing materials continue advancing, things keep improving. Taulman3D's Bridge, for example, is easy to print with and nearly indestructible.

That being said, I wouldn't argue that a $50 3D printed prosthetic is better than a $10-50,000 commercially made prosthetic. But what I would say is that it's $50, which means that it's a viable option for millions of people. And that's a BIG DEAL!

Why is national healthcare "unrealistic"? It works for plenty of countries. Heck, when we set up the new government in Iraq it had national healthcare. It may be difficult in the US for political reasons (healthcare companies contribute oceans of money to politicians, and they're not terribly interested in efficiency or outcomes, just profits), but since it demonstrably can be done, and works well, it's entirely "realistic".

The point isn't just that it's cheap ($300!), it's that it's a consumer-friendly printer that can be used "out of the box". So price matters, but so does the "out of box experience" and usability.

The Printrbot Simple is a very nice little printer. But at that price it's a kit that requires assembly, and the result looks like a weird machine made of wood and wiring with moving parts exposed. And the software is the same techie-looking software everyone uses. Which means that it's not an option for someone who wants to buy a printer, plug it in, and use it. And even the assembled cheap printers (Printrbot, Solidoodle) are terrible looking with not-great software. That's fine for early adopters who want to learn and are willing to suffer a bit (i.e. people who hang out on Slashdot). But if you don't think that consumer friendly industrial design matters, you're probably confused by everyone bought iPod instead of the HanGo PJB-100 (the first MP3 player with a hard drive).

And the Peachy (I'm a backer) isn't at all comparable. For $99 you're really only getting a part of a printer - you need to provide two water reservoirs, and a frame to hold it all together, and dedicate a computer to driving the Peachy. Because resin printing is extremely slow. So the Peachy is a fine learning experiment to cheaply play with resin printing, but other than the very low price, it's nowhere near consumer friendly.

Now, how this printer it plays out in reality is anybody's guess. But if they can deliver a printer that "just works" for normal consumers, for $300, that's pretty impressive, and I think it'll get them some serious attention. They're already well over their target, and it's only been a day.

There's certainly room for 3D printers to drop in price by improving the design manufacturability. Some of what they're doing makes sense to me.

- Use injection molded case as the structure. This costs more up front, but eliminates many parts. Very similar to how printers went from big machines with lots of screws and rods to almost all plastic. Sure, it's not as durable and rigid, but that might be an OK tradeoff for really cheap.
- Use of lighter components (carbon filament rods, etc.) allows use of smaller motors, which have less mass and consume less power. And they put less stress on a plastic frame.
- The main consumers of power are the heated build platform and the extruder's hot end. I don't see how they can reduce the hot end's power consumption much. But if they figured out how to print ABS on an unheated print bed. that's not bad.
- Printing ABS on an unheated print bed seems challenging. But keep in mind that for small print areas, curling is less of an issue. And perhaps they've found a way to get ABS to stick to the "ABS platform" well, but not permanently.
- They could be doing automatic leveling by measuring the build platform's position, then using software to "level" the print. Marlin firmware can do this now. It's pretty cool, actually - the firmware does the math to rotate the object so that it's square to the build platform, even at an absurd angle, and the extruder steps up and down Z as it moves across X and Y in order to maintain a constant layer height.

The main thing that gives me confidence is that they appear to have multiple printers running now, so they're ramping up manufacturing of an existing product, not inventing anything new. And the design looks like an evolution of existing printers, so they can use most of the existing technology "off the shelf" and just make the specific changes that they need. So it's a much easier product to engineer than a fundamental new technology. If you look at it, it's fairly similar to any H-frame printer, but lightweight and small. From my manufacturing experience, the dates seem aggressive, but since they're doing it in the US, they might save some time on iterations, shipping, etc.

Fused Filament printing is just another technique, with benefits and weaknesses. On the 'pro' side, it's very cheap, and it lets you make things that are quite strong, so they can stand up to routine usage. On the 'con' side, the resolution is limited, and you need to cool prints evenly or there can be curling or cracking. The issue isn't in going from liquid to solid, because until the plastic is solid it can't cause any stress on the part - when it's soft is just stretches! The issue is actually a bit later in the process, when the solid cools from warm to room temperature. PLA doesn't have this problem (it's rate of shrinking as it cools is tiny), but ABS shrinks about 2% when cooling from a warm solid to a room temperature solid, which is enough to cause curling or cracking in large prints. The solution is to keep the entire print chamber warm, then let the whole object cool at the same time when the print is done. Or print using PLA, which doesn't have this issue.

Resin printers have great resolution, but they're expensive, the material is tricky to handle (it's a liquid that you have to store in a cool, dark place, expires, and smells terrible). And the resulting objects are quite fragile. And you can't print with multiple materials. So it's great for display pieces, or for using as models for casting. But it's terrible for making things to use. Resin printing pre-dated fused filament, by many years, but it was largely abandoned once FFF emerged, due to these problems.

The other technologies are much more expensive. SLS is awesome, if you have $100K+ for a printer, and are willing to spend much more per print.

There's already CAD software that's easy enough for kids to use, as proven by the fact that kids are using it!

TinkerCAD and Sketchup are all easy enough that my son was using them when he was six.

So that's not what's holding 3D printing back. :-)

Personally, I don't see _anything_ holding 3D printing back.

Some people just want to download and print things, and for them there's Thingiverse (and to a lesser degree other repositories) with tens of thousands of things available for free. And there are some for-pay repositories as well, though they're small. And increasingly companies are providing printable STLs of stuff, so you can print your own. So they don't have to deal with stocking replacement parts.

Where 3D printing is great is personalized stuff. And for that, there are tools like Thingivere's Customizer. These allow designers to create designs that are configurable by users. For example, I've published a 3D printable wallet that you can put your name and address into, so it's uniquely your wallet (and more likely to be returned if it's lost). And there's a measuring cup that can be made any size you like, a pen with your name printed in it, and all sorts of other things. There are hundreds of Customizable designs, and more all the time. These let people who aren't designers print things unique to them.

And, of course, there are easy design tools like TinkerCAD and Sketchup that kids use all the time to make things to print. Heck, you can even use Minecraft to model things, then print that.

And even the professional CAD software is getting a lot easier. The fact that Blender is hard to use doesn't mean that all CAD programs are hard to use, just that Blender is hard to use. :-)

That's why I said "if the references weren't phrased literally the same way every time, but were more natural references to the stories, then even the phrases would be impossible to decode". To perhaps make this more clear, if there were a dozen references to that episode in a discussion, but each was expressed uniquely, which is how people actually communicate conversationally when referring to a shared context, translation software wouldn't be able to tie the dozen references together. For example, there are numerous phrases to refer to parts of that episode - "When Picard Met Q", "Space Jellyfish", "Tortured Space Being", "Groppler Zorn", "Humanity on Trial", "Data rattles off definitions", "Q kills Torres", "McCoy returns to the Enterprise for the Last Time" or "The first step towards meeting the Borg". If there's never any repeated phrases, just a variety of references to the same shared story, neither a person nor a computer can learn the phrases. They'd have to spend the time to learn the stories, then they could understand the references. Which is what Picard did.

If you only need _one_ thing 3D printed, I'd suggest using a service bureau such as Shapeways. Now, if you want to learn how to do 3D printing and use it more generally, go for it! But C/CMYK 3D printers are wicked expensive to buy for a one-off project.

Exactly. 3D printing of things that are mass produced and mass distributed makes no sense. But the huge range of "obsolete/obscure" stuff is perfect for 3D printing.

For example, I 3D printed replacement clips for my dishwasher that saved me $800 in repairs. The company wanted to replace the entire assembly because they don't inventory a single clip. So I measured and printed it. http://www.thingiverse.com/thi... . I love that with Taulman3D Nylon I can 3D print parts that are as strong or stronger than injection molded plastic.

Yeah, who needs more than 640K of RAM anyway? What's the global market for computers - 100? 200?

Yes, if you don't value/benefit from the ability to do something yourself, in your own home, then using a service provider makes sense. That's the business Shapeways is in, for example. They buy and operate industrial-grade 3D printers (the $500K kind, which can print metal, ceramic, etc.). And it's great to have as an option - I sometimes use them for the 'final' prints, after I'm done doing the rapid iterative design process on my home printer.

That being said, the home printers are MUCH less expensive to operate than the high-end printers. The high-end 3D printers all use very pricy proprietary consumables, so their customers are kinda getting ripped off (quite similar to ink jet printers). In contrast, the home 3D printers are open, with a highly competitive marketplace of vendors selling consumables. So the end result is that printing at home is much cheaper and faster than printing on the high-end machines, which are optimized for predictability, but are much more expensive and much slower. The result is that the home 3D printer market is innovating circles around the commercial products.

It's weirdly the opposite of printing on paper. Commercial presses are all "open" with many companies selling ink and paper, which are a highly competitive marketplace, while the home printers are all locked into absurdly overpriced, proprietary consumables. But still, millions of people buy home printers because of the value of being able to print at home, and that same dynamic is true with 3D printers, perhaps moreso because home 3D printing is better/faster/cheaper than the commercial printers. The main limit is, like early laser printers, in educating people that they're now empowered to do the kinds of things that they've never been allowed to do. And those transitions are always slo.

But having demo'ed 3D printing for a few years now (Maker Faires, MineCon, etc.) I can tell you that when people realize that they can do "impossible" things, they get quite excited. I suspect that's why 3D printer sales have been growing geometrically now for a few years, and as every generation of printers gets more polished and consumer-friendly and cheaper, the sales keep ramping up.

As a warning, though, there is one home 3D printer company (Cubify) trying to DRM-lock their customers into proprietary consumables (and then rip them off by charging 3x the open market price). Let's hope they keep failing in the marketplace.