Stereolithography, the modelling process that turns liquids to solids on exposure to light, was discovered by Charles Hull, who went on to form 3D Systems Inc back in 1987. Eight years later and now renamed 3D Systems Corp, the Valencia, California-based computer-aided design company has released an upgrade to its QuickCast software, which uses stereolithography techniques to prototype metal solids. Quickcast software takes computer-aided design data and slices it into two-dimensional cross-sections that are then drawn by ultra-violet laser onto the surface of a photopolymer. The beam traces rings in the liquid structure, which then solidifies and the process is repeated until a entire solid shape is created from liquid plastic. Prototyping using stereolithography patterns has cut the amount of time it takes to produce a physical model from design data but could hitherto be used only for non-metal objects. However, QuickCast enables solid modelling of metal objects, which have traditionally relied on wax patterns in the shell investment casting process. Instead of building a solid mould, QuickCast creates an internal structure with a outer skin that collapses when heated, leaving a metal solid. 3D Systems says the latest version of QuickCast gives a better surface finish and also has a higher yield of castings gained from the stereolithographic patterns. The Mercedes-Benz AG division of Daimler-Benz AG is using QuickCast 1.1 in the manufacture of its four-cylinder engine block. The automaker says the software will reduce the time to market for its new Mercedes range from 40 to 50 weeks down to just five weeks.
