Research On The Key Techniques Of Data Pre-Processing For Rapid Prototyping With Stereolithography

Stereolithography Apparatus (SLA) process is the most well-researched and the most widespread rapid prototyping technique. The emergence of SLA is a major revolution in the manufacturing. The data pre-processing process of SLA influences the quality and cost, or even related to the success or failure of the production. In this paper, inspecting and repairing the STL part's errors, optimal fabrication orientation and automatic support generation are studied, to improve production efficiency and quality and to ensure fabrication finished successfully.(1) Removal of redundant vertexes and reconstruction of the STL part were had in-depth study, as well as the inspecting and repairing the holes etc. common errors in order to facilitate the further data processing.(2) Three objective optimization model functions of fabrication orientation of SLA were designed, which were considered in view of enhancing part quality, reducing building time and minimizing the number of support respectively. A multi-objective optimization model was implemented by using the linear weight approach which was solved by Genetic Algorithm to get the optimal fabrication orientation.(3) Then, the areas which need supports were found based on the orientation. After that, the reinforce support lines were added in all the area through scanning. Finally the height of the supports was calculated based on the corresponding information of STL model.(4) Using VC++ and OpenGL graphics library, a RP data pre-processing software framework was programmed, which could inspect and repair STL part's errors, select the optimal fabrication orientation and add support structure automatically. The software has a good interface and maintainability.Based on the SLA data pre-processing software which could be got that were the optimal fabrication orientation of model and model's support structure, and the models were made in SPS350B rapid prototyping machine, experimental results indicate that the integration degree and process efficiency of RP system can be improved.