Geometric techniques for efficient waste removal in LOM

A new CAPP system is proposed for the layered manufacturing technology of LOM (laminated object manufacturing). The traditional technique wastes much effort and time in the generation of rectangular grid patterns onto the exterior of the model to facilitate waste removal. In the proposed approach, several geometric properties of the model are exploited to dramatically reduce the waste removal grids. This, in turn, leads to reduced build time with no effect on the build quality. The proposed method uses parting planes similar to those used in mold design in regions external to the part's convex hull, and an octree decomposition in the remaining regions. An integrated CAPP system incorporating these ideas has been developed, and several example parts demonstrate the efficiencies that the system delivers.