Research And Development Of Low-cost Destop Mask Projection Stereolithography System

Rapid prototyping is a kind of new advanced manufacture technology based on the principle of additive manufacturing,with which the physical prototype of the parts can be fabricated rapidly form its CAD models,thus it is an indispensable technology for the research and development of new products.Low-cost and desktop Rapid Prototyping System has been the research focus of rapid prototyping industry nowadays.Low-cost System means that it is the lowest cost of hardware and software on the assumption of good quality.Desktop System means that it is fit for office and has compact volume,light weight and also high speed,low noise in molding process.After researches of several typical RP process,MPSLA(Mask Projection Stereolithography)is chosen as low-cost and desktop Rapid Prototyping System.The system scheme design,layout design and parts design have been achieved by using the mechatronics design and modularization method.To simplify the control system of MPSLA Machine and reduce the cost of MPSLA Machine,the control system of MPSLA machine based on Raspberry Pi is presented.Raspberry Pi is used as the core of the control system of MPSLA,and Linux is used as the operation system.The control of the projection of mask image and the lifting motion of platform is realized with Python program,and functions such as remote login,document transmission and real-time monitoring to MPSLA Machine are implemented by using the Raspberry Pi of accessing internet.This control system reduces the space and the cost of MPSLA Machine largely,and provides the function of remote operation which helps MPSLA machine to enter the mass market.In order to improve the fabrication resolution of Mask Projection Stereolithography(SL)system and fabricate small part with fine structure characteristics,an optimization method of the mask image based on grayscale transformation processing is proposed.The mechanism which light intensity distribution affects fine structure characteristics is investigated.An optimal model of mask image is established,and grayscale transformation is processed by using geometric heuristic algorithm with VC++ 6.0.As a result,the distribution of light intensity on the exposure plane is changed.The experimental investigation shows that the object fabricated by using the optimization method of the mask image has a more clearly and smooth outline,and the experiment result indicates that the system has higher fabrication resolution.