Additive manufacturing of non-planar layers with variable layer height

Abstract The freedom and potential gained by creating objects layer-by-layer using additive manufacturing technologies is offset by the limitations the 2.5D process holds. Currently, surface quality and mechanical properties of parts are limited by path planning algorithms. This study presents an algorithm for non-planar path planning with variable layer height, enabling the accurate representation of freeform surfaces and introducing the potential for increasing the parts’ mechanical properties by tailoring the layers to the load-case. By using mathematical functions to describe non-planar layers and calculating the amount of material to be extruded, layer thickness may vary inside the same layer, enabling transitions between different curved layers without introducing air gaps. In addition, means for selecting a beneficial nozzle geometry for non-planar additive manufacturing are presented. Finally, manufactured parts are evaluated, showing the benefits of the presented method. Specifically, it is shown that surface roughness can be reduced by 76% for curved top surfaces and indications for improved mechanical properties can be derived from performed tests.