Influence of building strategies on the accuracy of parts in selective laser sintering

Shrinkage in selective laser sintering process is primarily influenced by material, process parameters and the geometry of the fabricated part. The part inaccuracy due to this shrinkage is overcome by calibrating and compensating it. Further improvements in accuracy of the part can be achieved by conducting more studies to appreciate the nature of deviations, by subjecting calibration part to varying build conditions. This paper presents the results of the experimental study carried out to understand shrinkage behavior in selective laser sintered polyamide 12 parts. Due to the inherent nature of the process, the shrinkage behavior is often influenced by exposure strategies, part positioning, part orientation, and other compensations applied to the part. When fabricated under different settings, shrinkage behavior of calibration parts tends to differ from usual. In the present work, the variations in error patterns due to different strategies in building the calibration part have been reported. The discussions presented in this paper on the shrinkage behavior of plastic parts are likely to make the process of compensation efficient and hence aid in improving the accuracy of the process.