Manufacturability analysis to combine additive and subtractive processes

Purpose - The purpose of this paper is to propose a methodology to estimate manufacturing complexity for both machining and layered manufacturing. The goal is to take into account manufacturing constraints at design stage in order to realize tools (dies and molds) by a combination of a subtractive process (high-speed machining) and an additive process (selective laser sintering). Design/methodology/approach - Manufacturability indexes are defined and calculated from the tool computer-aided design (CAD) model, according to geometric, material and specification information. The indexes are divided into two categories: global and local. For local indexes, a decomposition of the tool CAD model is used, based on an octree decomposition algorithm and a map of manufacturing complexity is obtained. Findings - The manufacturability indexes values provide a well-detailed view of which areas of the tool may advantageously be machined or manufactured by an additive process. Originality/value - Nowadays, layered manufacturing processes are coming to maturity but there is still no way to compare these new processes with traditional ones (like machining) at the early design stage. In this paper, a new methodology is proposed to combine additive and subtractive processes, for tooling design and manufacturing. A manufacturability analysis is based on an octree decomposition, with calculation of manufacturing complexity indexes from the tool CAD model.