Influence of printhead incline on the accuracy of robotic 3D printed spatial polymer struts

Abstract

The aim of this paper is to find suitable printing strategies and process parameters to ensure the ability to produce support-free polymer lattice structures. The main objective is to achieve good geometrical accuracy of strut-based lattice structures to ensure the manufacturability of larger structures as well as good structural stability. To achieve the stated goal, a statistical model of the effects of the individual process parameters and their combinations was created. The model enables the identification of optimal process parameters to ensure the guaranteed printability of the structure. The printing strategies determined in this way are tested to enhance the accuracy of the final print and the quality of the joints in the strut connection. The accuracy is assessed using optical 3D scanning. The average deviation of samples with optimised parameters and strategies decreased to 25% in contrast to the deviation of initial samples from DoE. More importantly, the maximum deviation (0.5 mm) decreased to 11%, so the whole process is more stable and predictable. This study presents an initial investigation of trapezoidal-cell printing strategies. The developed methodology has since been applied to larger lattice structures of BCC topology derived from the same basic geometry, which will be described in future work.