Ok, I was a bit overzealous with the Apple comparison. But the fact of the matter is, I don't have blinders on, I've got capitalist glasses on. This response is being typed on a $600 cell phone, which by all rights should cost no more then $200, but we live in a capitalist society. The cost of a 3d printer could be driven down dramatically, but you will never get quality out of mass production. And you will NEVER get quality parts (end user quality) out of an FDM printer.

IF this sort of printing ever manages to take over in the home, it will be with resin printers.

http://blog.makezine.com/2011/04/03/homebrew-liquid-resin-3d-printer-gets-resolution-boost/

And the issue with them isn't the cost of the hardware, its the cost of the resin itself.

Not for precision.

But that's part of the question. Can you laser sinter from powder, and then heat treat it after the fact, after you've made the part?

    I play with software and plastics, and make robotics move. Software guys make poor mechanical guys, and we're talking metal here, so I just don't know for sure.

No, but you STILL cannot buy a computer for the same price scale as the first Apple, Commodore, etc.. I'm not saying they are going to continue to go up. I'm saying they're going to stick around 2-3 grand, and stay there for the models which world relatively well.

You will find cheap ones that work crappy, don't print very accurate things, and gum up a whole lot. We've been working with these printers for years now. The cheap '3d printer in every home!' don't work for crap for anything you'd have an every day practical use for. The reason why they went up in price is, it's just not feasible to make them that cheaply. For example, your never going to get a cheap linear Z axis, because the precision required is, by definition, expensive to make. And they always have been. Combine that with 4 additional axis. This isn't just an inkjet printer, it has 6 axis to deal with an coordinate. X, Y, Z, Temp, and Feedrate.

Right now, your printing out shower hooks. If your engineering, you can print out small pieces which look like what you want to make. As a matter of fact, one of the BEST uses is to print it, and then use it to mold something which can actually MAKE your real part cheaply.

I'm not saying manufacturing won't evolve. But, in my opinion, it will NEVER evolve to be 'the replicator'. Things get cheaper as you manufacture them in mass. Even if you had a printer which was manufactured in mass, it's output wouldn't be, and thus, it's overall cost of operation is still going to be dramatically greater then someone making it. The assembly line took over manufacturing for a reason. A Carpenter could make you anything, but industry can make you millions of anything.

Tools have matured. But it's all still the same. As a matter of fact, many of the front end applications have configurations to say this G means this, this one that. To make it even easier, generally the FDM printers slice the whole thing up into nice strait lines, making things a bit easier.

    But basically, the tools are exactly the same. Software guys have just gotten really good at it. :-)

    As a matter of fact, some of the slicers can slice *and* drive CNC paths. But the 3d printer ones have evolved. An example of a nice one is http://slic3r.org/

Is now a good time to point out that 3d printers have been around for 20 years? Or is this a bad time...

Tell you what. You go ahead and make that gun, and let me know how it goes.

    As for the cost, the guns which they have printed where printed on a $20,000 printer, not a, 'Oh look, lego's at home!' printer. Second of all, those home printers have gone from $500, to 750, to 900, to 1100, to 1500, to 1800, now to 2200-2500. They aren't getting cheaper. What exactly makes you think that they're going to get cheap? FDM printers are notoriously finicky, and generally require service by either a technical user, or a support maintenance guy to keep them running. It's the side effect of having a very expensive glue gun.

    As for the laser sintering, common. The laser required is strong enough to liquefy steel. By your logic, why isn't my battery powered by little fusion reactors by now. I mean, it's just going to get better, cheaper, and mass produced, right?

Because when it blows up, it's going to rip your face apart. When it fails, it's going to fail and take your hand/cheek/eyes. And I doubt they'll come with a 3d printed emergency room.

It would be much easier to go to the hardware store, and make a gun. And you obviously haven't the foggiest idea as to how 'cheap' 3d printing really is, nor have you compared how much it is to buy a cheap 22 cal.

I actually started out with that argument. But if you can sinter stainless steel, you can harden it just like you normally would (I think).

I'm not saying it's practical, right now. But the word never is perhaps not a good choice.

Laser sintering, but it cannot produce hardened metal needed.

On the other hand, I suppose sintered steel could be hardened. Hrm..

Still is never going to be cheap due to the cost of the lasers, etc.

You are aware that all of these 3d printers use G-Code, right?

Laser sintering of metal parts is not, in any stretch, going to be cheap for a home printer to do. Additionally, laser sintering cannot produce the hardened metal needed for the upper receiver. Go ahead and try it. You'll blow your face off as the barrel eventually bubbles and bursts.

They've printed some of the parts of a gun.

    They still need barrels, and most importantly, firing mechanisms. The printed parts are currently still holding all of the 'metal bits' that make up the gun.

    Besides, the ATF really wouldn't be able to do much about it, unless they where being sold..

The fact is, Samsung's GS3 and the iPhone 5 are the two top kahuna's as far as installed userbase is concerned. They are still neck in neck in competition. Your argument is, 'At least we have 51 iPhone 5s for every 49 GS3's!'. So basically, what IS your point, anyway?

The point is, Samsung has done NOTHING but gain on the iPhone. It would be ignorant not to acknowledge that fact.