the prototyper takes information from a CAD model to build the prototype from layers of metal 1 to 2 mm thick. A plasma arc melts wire to provide metal slices, and the speed of the wire feed determines the thickness of the layers. Currently, the system uses steel and aluminum, but any metal can be used, providing the plasma arc is adjusted to heat it to its melting point.

"The final product has the right geometry, the right material structure, and the right mechanical properties," notes Doumanidis. "In other words, it will be strong enough to be a real product, not just a prototype or a mold. And it's cheaper to make a metal mold than to make one from an acrylic that costs 3$ a galloon."

This process, which earned Doumanidis last year's National Science Foundation Young Investigator award in manufacturing, couldbe of particular interest to the automobile, appliance, and toy industries. these industries make new models every year to meet Americans' appetite for trendy items, and this process could save time and money in prototyping and molding.
(Machine Design magazine, New Trends Section, page 22, Jan. 26, 1995)