Domain Decomposition and Space Filling Curves in Toolpath Planning and Generation

Ever increasing computer performance, along with significant developments in CADI CAM technology and high precision digital motion controllers lead to rapid and significant developments in the field of rapid prototypingjfabrication. Together, these elements offer a wide range of possible approaches in the toolpath planning issue; two main sets have been analyzed and applied to Fused Deposition Modeling process. Domain decomposition is a frequently used technique in computational methods. Within the context of present study, this approach is used to divide arbitrary layer geometries into smaller regions of simpler shape. A foreseeable advantage in such an approach is maximizing strength characteristics through thermal management. This is achieved by utilizing space filling curves which are mathematical entities that offer the possibility of building a wide range of structures, covering the surface of a single layer with one continuous curve. To evaluate the proposed concepts, ABS structures and ceramic green bodies have been successfully built. OVERVIEW The term toolpath planning is defined here as the collection of operations performed to provide the Rapid Prototyping hardware with the set of building commands. Although computer-controlled machines are now commonly available, the algorithms for driving them automatically are still subject of research. In CNC machining for example, human intervention and ingenuity are still necessary to design and build the necessary jigs for clamping of the workpiece. The integration of RP equipment with PC-based controllers offers the possibility ofusing common software development tools and resources for toolpath planning. Fused Deposition hardware is very similar to basic operation of pen-plotters and the machine level controllers are. based on .the same language. As a •. result, they .can. work more efficiently with patterns (i.e. porous structures) that have "polylines" as the basic geometric features, compared to the current mode of operation, which works on filled polygons (monolithic models). .