What stops the depressed school nut job printing an AK47?
http://www.bbc.co.uk/news/science-environment-22421185
not a lot
the guy that sells these actually stood in a room full of folks (well a lot of bigwigs from airbus and boeing and other stuff) and pointed out at the minute ,strength wise its about as good as an investment casting….
remember when your grandad used to go ,computers when i was a lad? its a bit like that ,not ready for the prime time but its coming
ps it will be surpassed by atom rearanging printers where elements are kind of arranged to produce stuff…ill be dead then though so making body parts from a pallette of elements will still be a bit late to print me new body bits
but expect medical folks to take the lead and make metal pretty obsolete