Possibilities and limitations of 3d printers

[GTOM]

I read more and more news about what 3d printers created.
I wonder about two things. Can they create engine parts that has to be durable, withstand big stress? Could they do it cheaper than old fashioned ways of forging metal? Also they write about 3d printed organs, but are they rather like prosthetics, or they could produce functioning, feeling organs in near future?

 

[Borg]

The main goal for printed organs is to solve the problems of dependancy on organ donation and rejection of the organs by the new host. I haven't heard of someone expecting to build an entire hand but, for internal organs, we are getting very close.

Anthony Atala: Printing a human kidney

 

[Chevreuil]

The fancy word for 3D printing is additive manufacturing. The reason for that term is that, in these production techniques, material is added to the final product, rather than removed. In a mill or a lathe you start out with a big chunk of metal and then you cut pieces off of it to get the shape you want. In additive manufacturing, you start out with nothing and then add material until you have the shape that you want.

There are a bunch of different kinds of additive manufacturing, and it's not like you can make a new liver with a 200 USD printer that is built for making small plastic toys. Different techniques and different machines for different materials and applications.

There is however, a kind of "3d printer" that handles high quality steel products. It's very expensive to run, however, and if you as a designer/manufacturer have the option to go with a traditional manufacturing technique, it will most likely be a lot cheaper.

Check this out. They made an old school steel pistol with an SLS machine.