Reconfigurable Multi-material Layered Manufacturing

Abstract

This paper proposes integration of reconfigurable manufacturing (RM) with layered manufacturing (LM) for development of reconfigurable multi-material layered manufacturing (MMLM) systems for fabrication of large, complex objects. We present a virtual prototyping system with reconfigurable actuators (VPRA) that can increase the number of materials, speed, and build volume to improve the efficiency and flexibility of MMLM. The VPRA system offers a test bed for design, visualisation, and validation of MMLM facilities and processes. It takes advantage of the convenient graphics platform of SolidWorksTM for constructing a virtual MMLM facility by selecting reconfigurable actuators from predefined templates. The characteristics, including the dimensions and relative spatial constraints, of the actuators can be conveniently configured to suit design requirements. Besides, a practical approach for toolpath planning of vector-based MMLM processes with multiple robotic actuators is proposed. It classifies and models the operational spatial constraints of possible actuator collisions, and indexes the deposition priorities of materials. The contours within each layer of a multi-material object are sorted according to material deposition priorities, material distribution on the actuators, and the spatial constraints for collision avoidance. The sorted contours are then arranged into a series of deposition groups for subsequent concurrent fabrication. The resulting toolpaths can then be simulated and validated through digital fabrication of complex objects. Case studies show that it can greatly improve the concurrency of material deposition, and hence reduce the build time of large, complex multi-material objects substantially. It can be practically adapted for control of LM processes with multiple robotic actuators.