  When manufacturing parts using material extrusion additive manufacturing and
anisotropic polymers, the mechanical properties of a manufactured component are
strongly dependent on the print trajectory orientation. We conduct non-planar
slicing and optimize the print trajectories to maximize the alignment between
the material deposition direction and the stress flow induced by a predefined
load case. The trajectory optimization framework considers manufacturability
constraints in the form of uniform layer height and line spacing. We
demonstrate the method by manufacturing a load bearing mechanical bracket using
a 5-axis 3D printer and a liquid crystal polymer material. The failure strength
and stiffness of the optimized bracket are improved by a factor of 44 and 6
respectively when compared with conventional printing.
