3D Printers are fun, useful and great to use, but that's only because I'm an architecture graduate. Making architecture models is kind of what early 3-D printers were designed to do, so no surprise there.

The best case I've seen for 3D is in space exploration....3D printers would allow a crew to create tools or parts as needed as opposed to having full sets and multiple spare parts...

Sure, it's expensive, but so is everything when we're talking about space travel...of course you can't build everything with a 3D printer but the potential advantages as far as saving space or independence from supply chains is hard to ignore...

I deal with this on a daily basis in engineering land.

Also ... a mid-range 3D printer for metal (metal dust laser-sintered together with the power of a standard TIG weld) is equivalent in cost to a low-to-mid-range 4-axis CNC center these days and can hold increasingly tight tolerances ±.002". It is very exciting and useful stuff that often allows for the manufacture of otherwise difficult to create geometry.

To answer the OP: I have no problems with 3D printers in the homes of every day people or in the offices of corporations.

I was thinking the same thing, creating custom tools for the job at hand. It's going to be very handy for space exploration and medical.

Just a quick note on the gun making, if it's the case then the technology might not be accessible to some. There are a lot of countries which has restrictions on weapon availability and making, can't see them allowing their people full access to 3D printers. Which would be a shame ...  was looking forward for the prices to come down and create some 3D jigsaw puzzles, I might not be able to have one down the track ...

from my own research on 3d printing, there are many choices (kit ones starting from $200 with all parts eg makibot (http://makibox.com/makibox-a6)) (built up ready to use from approx $1300) then there is the more 'professional' ones with more complete enclosures staring at $4000

as far as the msterials most of the cheaper units use either PLA (price range seen is $45 to $70/lb), ABS (lego type plastic) ($50-80/lb), PVA (water soluable very new to market only seen ing last couple of months) ($50-$80/lb), and typically print by extruding  the melted plastic with  the relitive accuracy of print improving with the increase of price (the cheaper printers only claim to use .3mm layers with the higher price ones getting down to .1mm

 and in the 'profeessional' types the printers can use a fair variety of materials although one of the more frequently mentioned material types is the light setting resins which can be set either by a laser OR a projected light path with a DLP type operation, but as other replies have mentioned there are even metal dust welding 3d printers that use high power lasers to do the welding.

and yes I am seriously looking at buying a lower price dual head plastic extruding 3d printer like this one http://www.3dprintersuperstore.com.au/collections/3d-printers/products/flashforge-creator-3d-printer-replicator-g#content

harpo

I have no doubt I'll be getting one eventually, but I'm still waiting for the technology to mature a bit more. I'm probably going to wait for some models with 2-3 print heads with different materials, and preferably the filament producing machines for recycling plastics back into usable materials.

As for that printable firearm... There's cheaper ways of producing much more reliable firearms... They're not a particularly advanced technology. A CNC machine would be a much better tool to use for such things, for example. A Lathe and CNC combined with a heavy duty press of some sort would give you pretty much all you need to produce much more useful firearms for similar prices to the high end 3d printers they're using for these things.

But....but...but...the 3D printer makes firearms in 3D......

I'm surprised nobody's done this yet... 3-D print phalli, I mean.

I worked with an open source hardware development group that hoped to ultimately make a self-replicatable 3D printer as one of its machines -- that is, a '3D printer' capable of producing an identical 3D printer using an open source premise -- full plans for building your own 3D printer such that anyone with the tools can do it.

I think, like peer-to-peer, there is a lot of promise ... but, yes, the potential for abuse, too.  I wish more independent creators would use peer-to-peer to distribute their music, movies, games, etc. legitimately and stop letting the RIAA and MPAA make everyone think that P2P is for pirates and pirates only.  Similarly, I hope the open source 3D printer idea takes off.  I knew that would come with the cost of illegal weapon manufacturing and distribution, unfortunately ... but that shouldn't taint the notion of a 3D printer any more than the fact some people hire hit men to commit murder with cash make everyone associate cash with immoral, illegal and unethical activity.

Eventually the cost will go down. The question is whether that will happen rapidly. Too slow, and either an even better means of production will become available, or (if it takes a really long time) the demand for such fabrication will fall off.

In an ideal world the prospect of being able to home-manufacture a fire-arm would TOTALLY prohibit the commercial release of ALL 3D printing/printers.

But of course that will never happen...not while the 'real world' includes the USA and its NRA et al.

Any minute now the Constitution is going to be yet again re-interpreted to say 'every American has the right to make his own guns....'

.....where are we going...and why are we in this handbasket?

You forgot PRESSURE COOKERS 

As far as the US is now concerned, anyone with with a pressure cooker in the kitchen and nails in the garage is storing 'weapons of mass destruction' and can be invaded without issue. Unless your a Mexican drug cartel, or a terrorist, then the US government gives you weapons.

why?

"The right to bear arms SHALL NOT BE INFRINGED"

cant get much simpler then that

starts at 0:30 

No, you idiot...don't you know the inbred response is..."you forgot about cars...."

Damn it...I need a better class of debater....