Modeling of non-planar slicer for improved surface quality in material extrusion 3D printing

Abstract: This paper introduces an algorithm to generate a 3D extruder path, combining classic planar and non-planar layers to enhance the surface quality and accuracy of complex 3D printed parts. Material extrusion 3D printing, due to its layer-by-layer construction method, produces parts with a discretization effect commonly referred to as the "staircase" effect, particularly on near-flat surfaces. The algorithm addresses this issue using a mixed-layer approach that uses 3D non-planar layers for the surfaces that would benefit from non-planar printing, and planar layers for the remaining regions. Existing studies have demonstrated similar combined layer methods but are often limited in the variety and complexity of shapes they can process due to their inherent slicing techniques. This algorithm presents a universal approach to non-planar extruder path generation by identifying the non-planar surfaces and generating non-planar extruder paths that conform to the object's surface. Subsequently, it identifies the space occupied by the non-planar layers and removes it from the original mesh to produce a collision-free planar-only mesh, sliced using classic planar methods. The algorithm was evaluated on objects of various complex shapes, comparing the results with outputs from standard planar slicers. The improvement in surface accuracy was also quantified by measuring the Chamfer Distance. Specifically, it is shown that the algorithm can generate non-planar extruder paths of complex geometries, improving surface quality.