Development of DLP-Based Stereolithography System

A low-cost stereolithography (STL) apparatus was developed to produce highly precise, three-dimensional (3D) structures from broad selection of functional materials, especially photopolymer resin. The developed stereolithography apparatus (SLA) utilizes focused light beam of wavelength range (300–700 nm) coming from the DLP projector and passing through the objective lens over the surface of a photocurable resin, which undergoes photopolymerization and forms solid structures. The photopolymer used in this STL system was polyethylene glycol di-acrylate and photoinitiator was Irgacure 784. The Creo 3.0 software was used for modelling of 3D object. A special MATLAB code was developed for slicing of the 3D CAD model. The Creation Workshop software was used to control the z-stage motion with the help of Arduino microcontroller, stepper motor, and ball screw. It also controls time period to display the sliced images through DLP projector and settling period. The experiments were successfully performed to built hexagonal cross-section and pyramid objects with 0.1 mm curing depth and two seconds curing time. The pyramid object with maximum 120 numbers of layers with 12 mm maximum dimension along Z-axis was build.