Development of a layerless additive manufacturing stereolithography machine to improve surface quality and dimensional accuracy

Abstract

Stereolithography (SLA) is an Additive Manufacturing (AM) process that has recently gained significant popularity in manufacturing research. The material used in SLA is a photocurable resin. SLA fabrication has conventionally been executed in a layered build process, which results in the staircase effect: a common problem in layered manufacturing giving a lower quality part surface due to created cusps on the surface. Manufacturing the part using a continuous build should theoretically eliminate this issue. A methodology for the design, development and calibration of a new layerless additive manufacturing system is introduced in this thesis. The methodology involves synchronizing the display of cross-sectional images with the platform elevation on an SLA machine and finding the optimal parameters in order to obtain a more dimensionally accurate and higher surface quality part. A variety of geometric features are constructed through experiments and their properties are examined to extract the most adequate fabrication parameters. The layerless process was found to reduce the staircase effect and the surface roughness on fabricated parts, as well as improve the ability of the machine to build complex features.