The killer app is "just in time" manufacturing of single parts from a gigantic library. This will create a "long tail" type business that can offer a huge line of obscure parts that otherwise aren't available, as the original manufacturing lines will have been closed down long ago.

Someday, 3D printing will probably be fast enough and improved enough to displace a variety of low-volume manufacturing applications. "Improved enough" to my mind would be manufacturing in metal with much more precise tolerance.

>The killer app is "just in time" manufacturing of single parts from a gigantic library. This will create a "long tail" type business that can offer a huge line of obscure parts that otherwise aren't available

Have you ever held a McMaster-Carr catalog?

I have. That is where I order parts for my 3d printer. Interestingly, you are making op's point because I frequently have to order from other places because as long a tail as Mcmaster-Carr can cover, it doesn't come close to being all that I need. It is essentially a comparison of a long, but finite tail vs. a practicaly infinite one (ie, anything I can create in a cad file).

> That is where I order parts for my 3d printer.

And you make my point :)

some of my parts :)

I have their catalog and order from them frequently. Did you have some point you were trying to bring up? Because the "long tail" type of business I envisioned in the previous post would be for stuff that's more obscure and, more to the point, discontinued.

I'm just trying to say that a company relying on "traditional" manufacturing methods can still offer almost half a million different, and mostly obscure, parts. I'm pretty sure they don't have half a million different production lines for that, and most of their stuff is CNC machined. So, if the demand for even more obscure or even completely custom parts ever becomes economically significant, they can probably adapt to supply that need as well, without using any 3D printing whatsoever.

Actually, McMaster doesn't manufacture anything, as far as I know. They are a distributor. (They tend to deliberately obscure this by refusing to tell you the brand name or actual manufacturer of any item they sell in advance.)

But back to the main point. The "long tail" type of business I envision is one that manufactures one-offs, or quantities so limited that the volume demand is below the level needed to interest a distributor such as McMaster.

The problem is the number of parts you're going to be able to produce is limited by the materials properties of whatever you're accreting.

Sure, you'll be able to produce anything that's mostly cosmetic, but how about something like the bearing housing for an old washing machine? I have to believe that will still get milled because it has to have certain mechanical properties a 3D printing process can't guarantee.

That's why I note that improvement would involve manufacturing in metal. This may be possible already to a limited degree, for example, with sintered metal, but that's an expensive process that isn't economical for washing machine parts.

Yeah, sintering could probably be done. But getting the right shape is only half the battle - you also have to get the right properties, which can mean getting the right kinds of dislocations and grain growth, which you normally only get by controlling the (high) temperature profile.

Laser printers are everywhere now. There's one in every office. But there are still printing presses.

Everyone expects that the "killer app" will be replacing injection molding or something. It will be something much more unexpected.

Exactly, and this is the example I use most frequently. Home printing let us make flyers for lost cats and party invitations. You could feasibly print out your own book, but no one with a brain would do it.

3D printing (which should realistically be called what is has been for years-additive prototyping) doesn't replace any part of the major manufacturing industry, it compliments it and makes it available to do a few things at home.

What about the ability for an AI to design appliances, furniture, etc for you based on what it knows anout you and the answers to any questions it thought relevant. Essentially your own personal architect, interior designer, industrial designer, etc wrapped up into one simple and quick interface.

Cool idea, but look at the unit cost. Right now, the per-unit cost is way too high to make that economical, especially for something large like furniture. Also, the value of your idea lies in the "human responsive AI," not the 3D printing.

Oh, I totally agree that unit cost right now is way way too high. That said it is many orders of magnitude cheaper to do a one off plastic part with a 3d printer than an injection mold. Also, 3d printers are just one small piece of the one off automated factory.