Automotive, electronics and medical design engineers are among the myriad professionals who have found that laser-based rapid prototyping technology can quickly turn their CAD drawings into full-scale models or even production parts. This popular technology has enabled many thousands of companies to speed up their new product designs, but one barrier to additional growth has been the trade-off between processing speed and part resolution.Perhaps the most commercialized rapid prototyping technology is stereolithography, which selectively scans UV light across a vat of liquid photopolymer resin to create complex 3-D parts. Advances in photopolymers and system engineering have allowed stereolithography's products to evolve from rough models to full-fledged prototypes and end products. Still, precise parts require long processing times, and fast production cycles produce less-precise parts -- unless system engineers understand how to optimize laser parameters to accomplish both precision and speed, up to the limit of other system components.Stereolithography user Pure Fluid Magic of Santa Clara, Calif., recently upgraded its laser to produce high-value precision parts to mount on integrated circuits to simplify on-board testing. Achieving the parts' tight tolerances and high surface finish (~10 under ANSI Y14.5) required a re-engineering process that provides an excellent lesson in understanding laser system trade-offs…