Multi-material stereolithography

A multi-material stereolithography (MMSL) machine was developed by retrofitting components from a commercial 3D Systems 250/50 stereolithography (SL) machine on a separate stand-alone system and adapting the components to function with additional components required for MMSL operation. The MMSL machine required construction of a new frame and the development of a new rotating vat carousel system, platform assembly, and automatic leveling system. The overall operation of the MMSL system was managed using a custom LabVIEW® program, which included controlling a new vat leveling system and new linear and rotational stages, while the commercial SL control software (3D Systems Buildstation 4.0) was retained for controlling the laser scanning process. During MMSL construction, the sweeping process can be inhibited by previously cured layers, and thus, a deep-dip coating process without sweeping was used with low viscosity resins. Low viscosity resins were created by diluting commercial resins, including DSM Somos® WaterShed™ 11120, ProtoTherm™ 12120, and 14120 White, with propoxylated (2) neopentyl glycol diacrylate (PNGD). Several multi-material complex parts were produced providing compelling evidence that MMSL can produce unique parts that are functional, visually illustrative, and constructed with multi-materials.