Experimental comparison of pinwheel and non-pinwheel designs of 3D-printed cycloidal gearing for robotics

Recent trends in robotic actuation have highlighted the need for low cost, high performance, and efficient gearing. We present an experimental study comparing pinwheel and non-pinwheel designs of cycloidal gearing. The open source designs are 3D-printable, combined with off-the-shelf components, achieving a high performance-to-cost ratio. Extensive experimental data is presented, that compares two prototypes on run-in behaviour and a number of quantitative metrics including transmission error, play, friction, and stiffness. Furthermore, we assess overall actuator performance through position control experiments, and a 10-hour endurance test. The results show strong performance characteristics, and crucially, suggest that non-pinwheel designs of cycloidal gearing can be a lower complexity and cost alternative to classical pinwheel designs, while offering similar performance.