Team Minion uses two UAV frame designs for the 2026 RobotX Maritime Challenge. Noodle uses an established commercial frame platform, while Kevin progressed through multiple structural iterations to develop a lightweight frame suited to its competition requirements.
Noodle uses a Tarot Ironman 650 frame with folding propeller arms and landing legs for ease of transportation. The carbon fiber tube and plate construction provides a sturdy and modular framework for mounting the vehicle's components.
Kevin's frame evolved through four major design iterations as the team worked to reduce weight, improve flight endurance, simplify system integration, and accommodate the vehicle's capture mechanism.
The first Kevin iteration used a fully 3D-printed frame divided into three compartments for the battery, electrical components, and capture mechanism. The design made extensive use of generative design to create a more efficient frame structure. The ESCs were mounted externally on the carbon fiber arms to improve heat dissipation. The lid for the electrical compartment incorporated a large heat sink to transfer heat from inside the enclosure to the exterior.
The primary limitation of this design was weight. Without the ESCs, the UAV weighed approximately 7 kg with the battery installed. This exceeded the legal UAV weight limit for the RobotX competition and limited the expected flight time to approximately 10 minutes.
The second iteration retained the fully 3D-printed design while consolidating the electrical components into a single compartment to reduce the overall size and weight of the vehicle.The ESCs were moved inside the frame to reduce wiring complexity and eliminate the need for heavier connectors required to route external ESC connections into the vehicle.
Although this configuration was lighter than the first iteration, the vehicle remained too heavy to achieve the desired flight endurance. The configuration provided an estimated flight time of approximately 15 minutes.
The third iteration focused on reducing the weight and complexity of the capture mechanism. Instead of using a separate fully 3D-printed capture ring, the vehicle's landing legs were incorporated into the capture mechanism. This approach combined structural and capture functions into the same components, reducing the amount of material required for the frame.
After an initial test print, the frame proved to be substantially heavier than anticipated. The team therefore abandoned the fully 3D-printed hull approach and moved toward a carbon fiber shell design.
The fourth iteration established the current Kevin frame configuration. The fully 3D-printed hull was replaced with a carbon fiber shell to reduce weight while maintaining the structural requirements of the vehicle. The shell was constructed using a 3D-printed plug as the forming structure.
Five layers of 0.4 mm carbon fiber were applied over the plug and bonded with epoxy. After the carbon fiber cured, the shell was sanded and finished with a clear coat. 3D-printed jigs were then used to align and secure the PPA-CF mounting interfaces for the arms and landing legs.
After the components were epoxied into place, the arms and legs were mounted to complete the current Kevin frame. The current configuration represents the progression from a fully 3D-printed structure to a carbon fiber shell while maintaining the mounting and functional requirements of the UAV.
