You're an ancient roman time traveller?

Actually.. I don't pay them to do it, I don't even live in the USA, but they still do it. Hell, they do it -more- to foreigners. If I had any choice in the matter, I'd opt out of paying for any such things here in the Netherlands too. Of course, that's not a thing that'll ever happen... governments and police forces / intelligence agencies are just too tightly intertwined.

Back in may 2012, more people used RepRap style printers than Makerbot-produced ones (even though Makerbots should, by all means, counts as RepRap-style, but let's not get into that). I'm not sure if the tables would've turned so much in one year. Perhaps they have. And yeah, I'm aware that RepRap might not count as part of the industry due to its DIY nature. But still, the article implies that most desktop 3D printers that people acquire/use are Makerbots and that just irks me.

I'd appreciate if you people had a gaze at http://surveys.peerproduction.net/2012/05/manufacturing-in-motion/3/, one page in a set of results from a survey back in may 2012. It may provide some useful insights.

To be honest, I think Makerbot may already have already acquired a chronic case of "money-grubbing" more than 3 months ago.

As a Dutchman (*le hinting cough*), I don't really consider Makerbot to be desktop 3D printing anyway. I'm much more partial to the original RepRap project, housing a great variety of different styles of printer with their own mechanics. I built my own for about 550 euros, perhaps 700 dollars or so. I know one person has managed to build a Reprap for $300, and it should be fairly doable to build them for $400 or similar. With welding tools, bulk deals on the electronics, a supply of broken scanners and printers, and an existing 3D printer, you could probably churn out improvised machines for near $250 or less. Not counting labour costs, since I'm assuming this would be a charity or diy type thing.

So no. I don't think only about myself, and I don't consider myself to be particularly American. But you may be right about Stratasys trying to sell a high-end printing service, I don't know enough to really make an educated guess about -that- particular possibility.

Since a lot of people have home 3D printers and there's sites where you can request for something to be printed on one nearby for a certain price, I think any company trying to sell "3D printing services" using FDM machines would have a hard time making much profit.

Seems fairly simple to me. Find the average mineral ratio of this ash, pour together readily-available types of material to get the same mineral ratio, see if that works. If it does, yay. If it doesn't, grind it up. If that doesn't work, find out of there's small structures in the ash that are important. If the latter, we could still use the recipe for special projects by using real volcanic ash.

The romans did it on a pretty big scale, as far as I understand. So industrializing it with current technology would probably be fairly easy. There's no real reason it should be pricey after it catches on, if it does so at all.

Even if so, it could be worth building things without rebar, imitating this recipe, if you want something that'll stand for thousands of years instead of 50. Sure, it may not have the same structural strengths to begin with, but it'll keep its strength much longer.

Good for art and such, or any building meant to be impressive or to be used for a long time.

My first robotics project was a Reprap. A mill or router wouldn't be that different. Doable if you're persistent, I'd guess.

An FDM printer (Reprap and the like) can work with gravity pointing in any direction, so there's no reason to assume it can't work without gravity. Powder printing might be less doable. Might have to make the powder wet to get it to stick together.

Having 4x the power would, naively, cost 4x as much. Having 3x extra power in the cloud means it can be used for other things when you turn your xbox off. Like, boosting the power of other xboxes. Many people probably use their console at most an hour a day on average. So you could get 24 times as much out of processing power in the cloud.

That said, eww. Good thing I wasn't planning to buy an Xbox anyway.

And there's ways to distribute such modified, safe software in ways that can't be reliably traced back to anyone specific. As soon as such a thing happens, the law is moot again.