[JoeAltmaier]

So, wave a wand and say "a robot will do it". That doesn't count as "A printer that can print a 2500 sq ft house".

Even imagine the robot exists: how exactly does it just 'plug in' the plumbinb and electrical systems? Currently it takes a person to scramble all over the house, drilling and fitting and connecting.

There is nothing being solved here. Just a blue-sky story about an imaginary printer.

[diydsp]

I am glad to see your justified skepticism of 3-d printer mania.

The real breakthroughs will come when people stop fixating on "printing" (extrusion) and realize it's the 3-d (4-d, 5-d, etc.) gantry that's the super-useful part. Fitted with different tools, such as painting, gluing and sanding tools, a 3-d gantry can be extremely useful.

There will however continue to be a "last mile" problem in Computer-Assisted Manufacturing (CAM) applications. These are the details, such as stripping wires, screwing in electrical boxes, etc. where the robot to perform these tasks is prohibitively expensive. The breakthrough is the 3-d gantry form, due largely to the reduction in prices of microcontrollers and power transistors, but it does not extend to all robotics, such as detail work.

For example, I've been watching videos on building guitars. I would love to see a 3-d printer friend explain to me how it's going to build a guitar from scratch. The economy of 3-d printing doesn't extend to the large number of distinct tasks, requiring different tools, techniques, process and forces in most objects that are useful in the real world.

This entropic mixture of difficult processes, I would argue, is the very reason WHY particular artifacts, such as a guitar, television set, couch, etc. are valuable in the first place. It is because no quantity of single, unskilled process (like shoveling coal) can produce them.

[VLM]

"I would love to see a 3-d printer friend explain to me how it's going to build a guitar from scratch."

I don't make guitars but I am guessing you could 3-d print most of a factory to make guitars. All the jigs and fixtures ready for use accurate to a 1/1000th.

What I do know about, and am interested in, is 3-d printing foundry patterns. Its harder to make a foundry pattern than you'd think, not just the obvious stuff like bulk material shrinkage and draft angles, but its really hard to handle differential shrinkage (warping, essentially). Its a complicated fine woodworking skill (assuming you're using wood foundry patterns). So you can't 3-d print a cast iron pan or an engine block, but you can print a pattern to be rammed in a sand mold and then cast some iron in the mold and ta-da a perfectly flat pan or perfectly straight engine block or whatever. This isn't a magic tool that'll make any idiot able to do foundry work, but it does mean that any idiot on the planet would be able to share world class pattern designs.

I would be happy to be able to print some holding fixtures for my metal lathe. You can't make crazy deep hogging cuts with flimsy PLA holding the work to the mill table, but you could do "something" at least.

I think people who expect 3-d printers to be magic star trek replicators are going to be very disappointed, although indirectly via one or two levels of indirection they will probably play a huge role in everything, soon enough.

Its just positive machining. Much as people don't use my negative machining traditional lathe and mill, I don't think joe 6 pack is going to be using a 3d printer on a regular basis, although much like negative machining revolutionized the world behind the scenes, sorta, positive machining will also revolutionize the world, again, behind the scenes sorta.

[moocowduckquack]

I would love to see a 3-d printer friend explain to me how it's going to build a guitar from scratch.

http://www.kurzweilai.net/the-worlds-first-3d-printed-guitar

edit - and a video of a 3d printed violin http://www.youtube.com/watch?v=XU3AZmf6O7I

[JoeAltmaier]

Very cool! Still, I doubt that plastic violins will win the hearts of musicians. They look different; they play differently. I won't guess if that sounded good or not; I've got a tin ear. But is sounded different. Calling it a 'stradivarius' was disengeneous. Its a plastic box that looks like a violin.

I think that 3D printing will win when it starts making things that couldn't be made before. How about an instrument with complex echo chambers impossible to reproduce with wood and glue?

[fudged71]

I can imagine someone saying something similar in the early days of the computer.

Could you watch the video? He already addresses these issues, and they are clearly researching how to do this. This is just a giant pick-and-place machine working with larger components. They already show that some human effort will be required in the assembly process, but hopefully will be much safer than what is done today.

[moocowduckquack]

how exactly does it just 'plug in' the plumbinb and electrical systems?

Lays them in as it builds presumably. Pick and place is easy with a big h-crane robot.