Some 3d printing services can print ceramics ;)

Services like that exist online, and they're excellent, albeit rather slow. I personally use iMaterialize because they have such a wide range of material options (everything from rubber to titanium) and finishes (for example, 4 different options for silver), but there's lots of others out there, and some are cheaper.

If you've ever played around with 3d modelling, I definitely recommend giving 3d printing a try, even if just a little test piece. :) Note that plastics are a lot cheaper than metals, although metals look the coolest.

And those nerdy kids will grow up playing around with and learning 3d modeling software to be able to make their toys.

This is a good thing.

What sort of 3d prints are you looking at?

Perhaps my expectations of 3d printers are too high because I buy from professional 3d printing services rather than using a low-end home 3d printer. They use high end products and sometimes do post-printing finishing work. But the quality of the stuff you can get is truly excellent, and out of a very wide range of materials.

Isn't that now the limiting factor?

So we have 3d printers in stores. Now we need all of the home devices that could potentially need spare parts printed to be available online, preferably in a unified database. You need manufacturer buy-in. Maybe some sort of certification mark that manufacturers can stick on their devices to show that printable replacement part models are freely available. I could use a new cheese compartment door in my fridge right now, for example. And I live in Iceland where shipping times are long and shipping costs / import duties high, so it'd make time and economic sense to print, too. But while having a 3d printer would be great, if the model isn't available, how does that help me?

Of course some companies, like iRobot, rely on profiting off of selling their spare parts.

It does seem rather weird to treat it as an intractable problem. Are we really talking about something that's AI-Complete here, like natural language understanding? Something not succeptible to a combination of chained rules, physics calculations, and statistical analysis? I seriously doubt it. So different machines can act differently due to wear, etc? Gee, people have never written programs to deal with that before, heavens no. So some things may require a decision from the operator, like whether to restart a defective piece or try to salvage it? Gee, I've never heard of a program asking the user a question during operation before! A piece of "printing" hardware experiencing a jam of some kind and needing manual intervention? Gee, nobody has ever experienced that one before!

I'm not saying that CNC machines and 3d printers are equivalent and that you can just swap a CNC machine in to the sort of role 3d printers are intended for. Of course the task of gouging out steel with power tools is a more intensive one than writing out plastic in layers with a slightly more advanced version of a hot glue gun. But we're not talking about creating superintelligent cyborgs here, we're talking about analyzing physical processes, including their various failure modes, and when a decision or action is required, presenting the user with the information needed to do that.

I'm sorry, I'm having trouble hearing you, your horse is too high.

Oh, and in #2, sound insulation would also be very important, both for the compressor (if compressed air is used, rather than bottled oxygen) and for the jet itself (which is basically like a tiny rocket engine). And I guess the filter isn't just about removing any incomplete combustion products from the exhaust, but also any dust or the like.

Even if it ultimately isn't suited for, say, a quiet home office, 3d printing isn't really an home office task, we're more talking about a "garage workshop" sort of thing. I'm just curious whether anyone has pursued such an approach, because at a glance it sure looks to have potential for making a very broadly capable product. I mean, such a system should even be capable of printing electronics, including resistors, capacitors, etc, maybe even some types of batteries (not anything requiring extreme precision, like a CPU, and li-ion batteries would be right out due to the thin, sensitive and rather complex membrane needed, there's no way you could just deposit that, but still..).

There's two types of processes that I'm surprised I've not seen more focus on.

1) Printing of, and then filling of molds, which can then be melted down and reused. That's how the higher-end 3d printed parts that you can buy online made, including almost all 3d-printed metal parts you get from online 3d printing services (the extra steps for metal being to coat the mold in a ceramic shell and melt away the mold). The only commercial 3d-printed metal that I'm aware of that doesn't work in this manner is iMaterialize's titanium, which uses laser sintering - and it has an out-of-this-world price tag.

It seems to me that if you used a mold, while in several ways it complicates the process (extra steps, preventing adherence to the molded object, etc), in others, it simplifies it. Your print heads don't need to handle a variety of materials or produce a pretty or durable product. They still need to be able to produce fine surface details but the ability to print thin structures loses importance. Once you've got a mold, you open up the floodgates to the sort of products you can fill it with, anything that will harden either through cooling or via chemical reaction, anything from thermoset plastics to candy.

(note I'm not envisioning a little hobby home printer that fills molds with molten metal in your office, mind you... although I could envision a more garage-scale or small industrial scale version that could handle such a task)

2) I've never even heard of a 3d printer being based on thermal spraying. With thermal spraying, you can choose the balance of precision vs. flow rate via nozzle size. Your materials are virtually unlimited, pretty much anything you can turn into a powder. It could conceivably even let you work with metals in a home environment, if the rate was kept low enough that heat buildup wouldn't be a problem (and you'd want an air filter on the exhaust, even though it should be pretty clean). You can choose the temperature and velocity you're spraying at by varying the pressures of compressed air and combustible fuel fed into the chamber with the powder, so you can work both with heat-sensitive and heat-requisite materials, as well as materials that can't stand high velocity impacts and materials that require them. Such a system could likewise do more than just print - it could add and then sectively remove substrates, it could engrave, it could change surface textures by sandblasting/polishing with various materials, it could paint or apply high-performance coatings - pretty much anything you can envision from a device whose fundamental workings are "shoot grains of material of your choosing at a velocity of your choosing (1-1000+m/s) and temperature of your choosing (cold to thousands of degrees)".

In both cases #1 and #2, I'm genuinely curious as to why there's not been more work done with them. Or perhaps there has been work done with them that I'm unaware of? I'm asking as someone who makes and buys 3d printed items online but has never printed one herself.

We are in a War on Faith, because Faith justifies anything and ISIS takes it to extremes. But in the end they are just a bigger version of Christian-dominated school boards that mess with the teaching of Evolution, or Mormon sponsors of anti-gay-marriage measures, or my Hebrew school teacher, an adult who slapped me as a 12-year-old for some unremembered offense against his faith.

Hm. The covenant of Noah is about two paragraphs before this part (King James Version) which is used for various justifications of slavery and discrimination against all sorts of people because they are said to bear the Curse of Ham. If folks wanted to use the Bible to justify anything ISIS says is justified by God's words in the Koran, they could easily do so.

18 And the sons of Noah, that went forth of the ark, were Shem, and Ham, and Japheth: and Ham is the father of Canaan.
19 These are the three sons of Noah: and of them was the whole earth overspread.
20 And Noah began to be an husbandman, and he planted a vineyard:
21 And he drank of the wine, and was drunken; and he was uncovered within his tent.
22 And Ham, the father of Canaan, saw the nakedness of his father, and told his two brethren without.
23 And Shem and Japheth took a garment, and laid it upon both their shoulders, and went backward, and covered the nakedness of their father; and their faces were backward, and they saw not their father's nakedness.
24 And Noah awoke from his wine, and knew what his younger son had done unto him.
25 And he said, Cursed be Canaan; a servant of servants shall he be unto his brethren.
26 And he said, Blessed be the Lord God of Shem; and Canaan shall be his servant.
27 God shall enlarge Japheth, and he shall dwell in the tents of Shem; and Canaan shall be his servant.

that actually works.

In my experience, teams with south asian ex-pat managers are always FDD, always have massive cost overruns, and always have massive attrition.

The US Constitution was an open declaration of treason against the Crown, which at the time controlled the most powerful military the world had ever seen. It was signed by farmers, lawyers, and doctors who had little in the way of protection against that army and little chance of surviving the fight. To say it was anything less than a suicide pact is absurd. The fact that few alive in this country today have their intestinal fortitude speaks volumes to why we're in decline. They had balls. Somewhere along the way, we lost them.

And if you don't think voting leads to people dying, you aren't paying attention.

As opposed to voting rights absolutists? Fifth Amendment absolutists? Rights aren't rights when you're only allowed to exercise them in a place and manner dictated by the government.