Development and Validation of an Additively Manufactured Tilt-Wing Actuator for a Subscale eVTOL Demonstrator

Abstract

To support ongoing research into flight dynamics and control functions for (tandem) tilt-wing eVTOL aircraft, a subscale flight test demonstrator is being developed. Tilt-actuators are essential to achieve the tilt-wing's key characteristics of VTOL capability and efficient wing-borne cruise flight. However, these actuators must provide sufficient torque and speed to navigate the challenging transition regimes between cruise and hover flight, involving high angles of attack and post-stall conditions, with these requirements remaining poorly quantified. Additionally, existing solutions leave room for improvements in terms of weight and hardware accessibility. This work develops and validates a high-performance tilt-actuator system to enable comprehensive flight testing across a wide range of dynamic transition maneuvers. The maximum torque loads and tilt speed requirements of the tilt-actuators are derived. A primarily additively manufactured tilt-actuator and gear system leveraging commercial RC servo motors is developed, optimized, and implemented. The optimization analyses reveal that helical polymer gears are 2.7 times lighter than conventional metal spur gear alternatives while significantly reducing the package size. Bench tests successfully validate the static strength, accuracy, and dynamic performance of the optimized system, meeting all derived requirements.