The race to produce small-series parts on demand, on location, will determine the shape of a $400 billion market.
Roughly half the use of 3D printing is now for prototyping, but experts think that, by 2020, 80 percent of the global production capacity of 3D printers will be dedicated to the manufacture of finished products. GE, for example, expects to make 40,000 jet-fuel nozzles by 2020.