A Robotic Multiaxis Additive Manufacturing System for Nonplanar and Dynamic Orientation Printing

In the future an automatic robot fabrication system is envisioned, that would enable a non-specialist user to parametrically design, and autonomously manufacture a bespoke robot, without the need for manual intervention or assembly. Additive Manufacturing (AM) is an attractive method for this as it is digitally driven and tooling free, which increases the speed and flexibility of production, while reducing costs for low volumes. Another unique capability of AM is the ability to embed components within the structure of a robot, while it is being manufactured. However, the state of the art embedding methods involve a series of manual steps. Additive manufacturing also has some inherent limitations which arise from building up parts from many discrete, planar layers. These include; anisotropic mechanical properties; curves approximated by discontinuous steps; and overhangs requiring support. Addressing these issues, while also enabling functional mechatronic components to be embedded, requires a new approach to Additive Manufacturing. This work introduces a novel 12-axis Additive Robot Manufacturing System (ARMS). This is shown to successfully 3D print high quality parts, comparable to other Fused Filament Fabrication (FFF) systems, using industrial robot arms. Using the multiaxis (i.e. > 3 axes) capabilities, it is demonstrated that the orientation of a print with respect to gravity has no effect upon its surface quality, but the relative orientation of the geometry to the layers has a significant influence. Using this relationship, components are printed using a dynamically varying build orientation, enabling unsupported, 90° overhangs with a constant, tuneable roughness to be produced. ARMS is then used to print nonplanar layers with greater curvature than has previously been demonstrated. Conformal layers are shown to improve the strength of curved parts by 57%. The capabilities are combined to manufacture the first mechatronic system with an integrated actuator that required no manual assembly, intervention, or post processing during or following the AM process. It is concluded that the multiaxis AM system successfully improves upon conventional planar deposition by overcoming key drawbacks to FFF, and could be a key enabler to a new AM process for the manufacture of integrated mechatronic and robotic devices.