Parametric error modeling and software error compensation for rapid prototyping

Kun Tong, E. Amine Lehtihet, Sanjay Joshi
2003 Rapid prototyping journal  
Rapid prototyping (RP) machines can build parts of complex geometry with very little process planning and human interaction, making them a very attractive manufacturing process. However, inferior dimensional accuracy of these processes is a major obstacle preventing this technology from greater penetration of manufacturing activities. This research presents a generic method for improving the accuracy of RP machines by error compensation using "virtual" parametric errors. It was inspired by
more » ... as inspired by techniques developed for parametric evaluation of Coordinate Measuring Machines (CMM) errors. Under this approach, the confounded effects of all errors in a RP machine are mapped into 18 "virtual" parametric errors which are used to build the machine error model. A specially designed 3D artifact is then built on the RP machine and measured by a master CMM. Measurement results are used to estimate the coefficients of the parametric error functions. Error compensation based on the derived error model is finally applied via software to the files which drive the RP machine. Two compensation methods were developed and tested. The first one applies compensation to StereoLithography (STL) files while the second applies compensation to slice files. Compensation applied to slice files theoretically allows higher compensation resolution, but machine control resolution must be sufficiently fine in order to take advantage of this strategy. The resolution of the RP machine used in this study to test slice file compensation was too coarse to distinguish significant differences between slide file compensation and STL file compensation. Nominal Position (x, y, z) Actual Position (x+dx, y+dy, z+dz)
doi:10.1108/13552540310502202 fatcat:3ucrsinyw5d7fe7pmaudws42ay