Multi-Axis 3D Printer Design Challenges for In-Situ Additive Manufacturing

Abstract

Abstract Multi-axis Additive Manufacturing (AM) is a prevalent technology that is currently limited to machines that only operate within enclosed volumes. Such an enclosed volume limits the size of additively manufactured parts. However, if the printing happens outside of the printer, the print-volume is unbounded. Furthermore, in adjacent printing, one could create and join a part at its eventual assembly — thus removing a step in the manufacturing process. A mobile machine like this would allow the operator to print infinitely sized parts on any surface and printing parts directly onto the work surface removes the post-print assembly costs and times. Robotic manipulators are commonly used in research applications of adjacent multi-axis 3D printing due to the accessibility and kinematic freedom of these machines. But, while robotic manipulators can print in many different orientations and on a variety of surfaces, the lack of rigidity in the rotational joints and complex inverse kinematics associated with them means that printing with these machines can be overly complex and yield imprecise results. This paper examines both the hardware and software design challenges in creating a novel multi-axis 3D printer designed specifically to print onto arbitrary surfaces directly adjacent to itself. Kinematics and joint rigidity are carefully examined in order to design an optimal configuration. Given the chosen kinematics, the computational systems needed to control the printer are presented in detail including calibration, part slicing, and toolpath creation.