[epaik]

I think the greatest use case isn't printing stand-alone objects, but rather replacement parts for existing products. Say, your laptop screen hinge breaks. Instead of ordering a new one from the manufacturer, you could print your own replacement at home.

[iamwil]

That won't be the case until 3D modeling tools get much easier to use. Current 3D modeling tools are either expensive, or hard to use. In addition, most average people aren't versed in thinking about objects in 3D in their minds. There are software like Matterport, where you can scan things, but until you can scan the broken parts, and "glue" it together in software easily, this won't happen.

It's like saying the greatest use case for computers is that you can program your own accounting program to do your own taxes. No. I went to the computer history museum, and they had a model of "easy to use" computer for moms in the kitchen. What was on the controls? Loading and unloading registers. They were completely off the mark on that one.

Chances are, it'll enable makers to offer services that have a real world component that other people can order easily, and enable new kinds of behavior.

[wtallis]

I know several kids who have, on their own, discovered and learned how to use SketchUp, without anything like access to a 3d printer as motivation - just a fascination with the idea of building virtual objects. It's a severely limited tool, but that's not enough of a turn-off to prevent them from learning the basics of 3d modeling. Since completed models can be readily shared amongst those who use 3d printers, I think it's safe to say that a lack of competent 3d modelers won't be a limiting factor for the growth of 3d printing. And as 3d printers become more affordable, the market for better affordable CAD tools with absolutely explode, with SketchUp racing to add more advanced features, and companies like SolidWorks trying to find a way to release an affordable product without completely cannibalizing their existing business model.

[iamwil]

I don't doubt the kids will pick it up quickly, just as kids picked up programming in the computer's early days.

But to the originally stated use case of fixing broken parts, I don't think that will happen as kids aren't usually running around fixing parts. And for the rest of us, only some of us have enough umph to learn how to 3D model. The vast majority need something easier to make the fixing broken parts scenario a reality.

However, I guess I can see a scenario where older people hire kids to fix parts, like how older people hired kids to do websites in the 90's.

[InclinedPlane]

The internet exists though. So all it takes is a handful of enthusiastic folks who are good at creating 3D models uploading those so that anyone in the world can use them.

[stevewilhelm]

The laptop hinge is probably metal.

The top to my blender is made of two materials, a very soft pliable plastic that is food safe and a ridget clear plastic for the handle.

These two very simple examples have at least three very different materials with very different properties.

It is going to be one very expensive printer that could work with lots of different materials. Even if it could be made cheaply, small batches of each material in custom colors and sizes would also be very expensive.

[TylerE]

The problem with that is that the current tech can't print anything with material that has any sort of reasonable mechanical properties - the stuff is quite fragile.

[epaik]

That's very true. But for smaller parts or cosmetic parts 3D printers can already be used to print replacements, as evidenced in a recent HN post[1].

[1] http://news.ycombinator.com/item?id=4589528