[Dave Colangelo]

I have seen a good amount of 3D printed parts as my University had a printer and it sat in the shop so everyone could see what came out. I have also spoken to people who 3D printed stuff from thwir Formula SAE cars and basically the parts are not very strong. We has the kind that layered thin layers of plastic which did not create a very solid structure. Although you could make a part fast (and it was not even that fast for a sizable thing) it was brittle and plastic. The power of the 3D printer as I see it is for quick ways to make molds or templates for test fitting.

That being said the tech is coming up quickly but for what its worth you could CNC a mold for a big plastic piece in about the time the printer took to make a single one (assuming it was a relatively basic part).

Regards
Dave