Design and Realization of a 6 Degree of Freedom Robotic Extrusion Platform

The layer-wise deposition of Additive Manufacturing (AM) processes allows for significant freedom in the design of product geometry; however, the use of 3-axis deposition tools results in layer interfaces that reduce material properties in the build direction. Adding additional degrees-of-freedom (DOF) to the AM tool could remove this limitation by enabling out of plane material deposition. For example, multi-DOF tool paths could align material extrusion with a part's stress contours to circumvent inter-layer delamination. As a step towards this goal, the authors designed, fabricated, and tested an AM extrusion system that leverages a 6-DOF robotic arm. In this paper, the authors detail the realization of this system including the design of a high-temperature filament extruder, kinematics and tool path generation, and user interface. The performance of the system is evaluated through layered deposition of ABS thermoplastic.