Parametric process optimization to improve the accuracy of rapid prototyped stereolithography parts

The functional requirements of a rapid prototyping system are speed and acc uracy, and they are both functions of vendor defaulted and user selected ma nufacturing parameters. Accuracy is evaluated by dimensional errors, form e rrors and surface roughness of manufactured parts. A specially designed spe cimen with 20 dimensional, geometrical, and surface roughness features has been used in the inspection of RP manufacturing processes. In terms of Tagu chi experimental design techniques, an orthogonal array of experiments has been developed which has the least number of experimental runs and desired process parameter settings. Using a 3-D coordinate measuring machine and su rface profilometer, a series of measurements in evaluating the SLA parts qu ality has been conducted to find the functional relationships between the o utput part quality and input manufacturing process parameters. Two analysis tools, response surface methodology and Analysis of Variance (ANOVA), have been used to evaluate the SLA RP process and to perform the product optimi zation. The optimal setups of SLA manufacturing parameters for both individ ual features and a general part with various features have been concluded f rom this study. (C) 1999 Elsevier Science Ltd. All rights reserved.