The manufacture and assembly of small-scale robotics can be expensive and time-consuming using traditional methods; especially when complex mechanisms are involved. By refining current additive manufacturing techniques a micro-scale walking robot can be 3D printed without the need for any complex mechanical assembly. The robot requires only the addition of simple circuitry and 2 motors, one for each of the 1 degree of freedom walking mechanisms before it is capable of being driven wirelessly. Once fully assembled, differential drive of the parallel leg sets allows for locomotion in any direction on a 2-D plane. The robot’s compact size; just 62 mm (x) × 38 mm (y) × 88 mm (z), and leg curvature makes travel possible through borehole/pipe diameters as low as 65 mm. By pushing printer tolerances to the limit, complex mechanisms can work in Non-Assembly at a small scale. Through the Query application of these Non-Assembly techniques to field robots such as those intended for use in the Pipebots project could allow for the production of large swarms of robots quickly and affordably.

Purpose: This paper aims to present a multi-axis additive robot manufacturing system (ARMS) and demonstrate its beneficial capabilities. Design/methodology/approach: ARMS was constructed around two robot arms and a fused filament fabrication (FFF) extruder. Quantitative experiments are conducted to investigate the effect of printing at different orientations with respect to gravity, the effect of dynamically changing build orientation with respect to the build tray when printing overhanging features, the effect of printing curved parts using curved, conformal layers. These capabilities are combined to print an integrated demonstrator showing potential practical benefits of the system. Findings: Orientation with respect to gravity has no effect on print quality; dynamically changing build orientation allows overhangs up to 90° to be cleanly printed without support structures; printing an arch with conformal layers significantly increases its strength compared to conventional printing. Research limitations/implications: The challenge of automatic slicing algorithms has not been addressed for multi-axis printing. It is shown that ARMS could eventually enable printing of fully-functional prototypes with embedded components. Originality/value: This work is the first to prove that the surface roughness of an FFF part is independent of print orientation with respect to gravity. The use of two arms creates a novel system with more degrees of freedom than existing multi-axis printers, enabling studies on printing orientation relationships and printing around inserts. It also adds to the emerging body of multi-axis literature by verifying that curved layers improve the strength of an arch which is steeply curved and printed with the nozzle remaining normal to the curvature.