Process planning in layer-based machining

Abstract

Some freeform surfaces cannot be machined by traditional CNC machining because of the inaccessibility to some critical points. Layer-based machining system developed by the authors can enlarge the accessibility by building a model layer by layer. Each layer is shaped by 5-axis machining. In this paper, the overall process planning techniques are identified and analyzed. The data flow chart in layer-based machining is established. The concepts of "decomposition for accessibility" and "decomposition for manufacturability" are proposed to decompose the model into manufacturable parts, which is called slabs. Adaptive slicing and interference avoidance algorithms are developed to achieve the maximum accessibility. A method called stock layer combination is proposed to select available stock layers for the process.