A new rapid prototyping machine additively builds parts that end up looking as if they were injection molded. The ZBuilder Ultra from Z-Corp., Burlington, Mass., makes components using a digital light processor projector that solidifies a liquid photopolymer. According to the developer, the machine builds working plastic prototypes in half the time needed by other RP machines and at one-third the price of using stereolithography. The machine makes parts with tolerances of +/- 0.008 in. with features down to 0.005 in. in size and smooth surfaces. The photopolymer’s properties are similar to those of ABS.