Travis Lerol, a software engineer demonstrates for the Washington Post how he prints out accessories for his AR-15 at home in Glen Burnie, Md.
Lerol uses a $1,300 machine called the Cube.
Printing accessories this size takes about 10 hours.
3-D printers like Lerol's are only capable of printing with plastics. However, expensive, industrial-scale printers that can produce parts made of high-grade polymers are expected to become more affordable as a result of the normal technology curve.