Axisymmetric non-planar slicing and path planning strategy for robot-based additive manufacturing

Conventional planar slicing methods for additive manufacturing limit manufacturable geometries and cause anisotropy and surface defects. Non-planar layers may address this problem; however, their complexity hinder automatic trajectory generation. This paper presents an algorithm for slicing part models and defining trajectories in axisymmetric layers using parametric curves as generatrix for surface creation. The algorithm is based on two coordinate systems, the Cartesian coordinate system c and a slicing coordinate system s. Thus, by defining planar layers in s, the model can be sliced with non-planar uniform layers parallel to the build platform. Commercial software was used to define these planar layers in s. To validate the methodology, two case studies have been defined and validated in a robotized additive manufacturing cell. The precision of this implementation has been validated by simulating the extrusion of material in the generated trajectories while measuring the distance between the extruder and the build platform. The results show how the variation in this measurement is dependent on the complexity of the geometry but consistent with repetitions, obtaining values of uncertainty ranging from ± 250 to ± 350μm. This methodology may enable new mechanical properties design for biomedical applications, structural components, soft robotics, or aerospace industry among others.