Audiís favorite new toy isnít the 1:2 scale model of their 1936 Auto Union Typ C grand prix car. Itís the printer that made it.

Like most car companies, Audi is constantly pushing the limits of toolmaking and other manufacturing processes. Their latest success is part of the 3D printing revolution, but the results are more robust than typical plastic prototypes because Audi is printing in metal.
The process is analogous the one used by tabletop 3D printers that melt plastic beads and extrude hot, sticky goo in layers, forming differently shaped plastic things. Weíve seen car bodies and even houses made this way.
Audiís process uses metallic powder ó either aluminum or steel ó with grains less than half the size of a human hair. The powder is melted by lasers, and applied in layers that can produce parts as large as eight inches cubed. Thatís not yet big enough to make even a TT (which accounts for the pint-sized grand prix car), but it can make complicated parts that would otherwise need to be machined or cast ó and, in some cases, printing enables the production of parts that are otherwise impossible to make. Not only does printing allow more precision for involved geometries, the resulting parts are denser than ones formed by die casting or hot forming. Audi sees a future in which metal printers are a staple of series production.