3D Infill Path Generation on Quadric Surfaces for Additive Manufacturing

Abstract Conventional 3-axis 3D printing has limitations due to the need for supports for certain geometries and in weaknesses along layer lines. Layers for these printers are entirely planar, leading to difficulty in printing overhanging material. The planar structure also allows the weaker inter-layer adhesion to align with stresses, making components prone to failure under certain loading conditions. The recent advent of additional rotational axes on these printers has allowed for a departure from using strictly planar layers, but the software needed to generate these non-planar toolpaths is not nearly as robust as current planar slicers. This paper proposes a method to generate the infill paths for printing on arbitrary quadric surfaces as opposed to only planar surfaces. The method uses coordinate transforms of the layer surface to ensure that toolpaths conform to the interior of a layer perimeter without leaving empty regions within the perimeter interior. This includes proper exclusion of paths within any interior cavities within the outermost perimeters. Two common 3D infill patterns, cubic and gyroid, are implemented and tested. Examples of sliced single layers and complete models are showcased and their structures are compared with those comprised of only planar paths. The viability of extending the method to other patterns in the future is discussed.