Structural Analysis and Redesign of an Injection-Moulded Drone Frame
Structural Analysis & Redesign
AOS RC provided structural analysis and engineering redesign services for a novel injection-moulded polymer drone frame. We helped the client transition the platform from an early proof of concept to a production-ready commercial architecture.
Technical challenge
The client developed an initial prototype frame using a carbon-reinforced polymer. Before investing in high-volume injection-moulding production tooling, they needed to validate the structural integrity of the design.
Our initial Finite Element Analysis (FEA) identified two critical vibration issues. First, a low-frequency twisting mode occurred near the flight controller mounting area due to low torsional stiffness. Second, the drone arms exhibited insufficient bending stiffness. Furthermore, the frame could not accommodate standard 10-inch propellers, lacked universal mounting points for commercial payloads, and lacked the internal volume required for advanced flight electronics.
Engineering approach
We used computational models to optimize the frame geometry and resolve these mechanical limitations without adding unnecessary weight.
Vibration and Stress Optimisation: We adjusted the frame joints and tapered the structural members to reduce localised stress concentrations. Our analysis showed that increasing the thickness profile of the arms significantly improved bending stiffness and mitigated the primary twisting mode.
Mechanical Redesign: For the second-generation design, we engineered the drone arms with optimised internal stiffening structures. This internal geometry maximised the stiffness-to-weight ratio of the material and successfully resisted torsional twisting during high-yaw manoeuvres, ensuring clean gyroscopic data for the flight controller.
Component Integration: We expanded the internal tray to house standard enterprise flight controllers (FCs) and electronic speed controllers (ESCs). The overall mass distribution was calculated to maintain a centralised centre of gravity with various commercial battery form factors. We also integrated a standardised mounting grid on the top plate to allow direct attachment of peripheral hardware.
Outcomes
Delivered a complete CAD design package optimised for mass production via injection-moulded Polyamide Carbon Fiber (PACF).
Resolved critical twisting and bending vibration modes to ensure stable industrial flight performance.
Achieved full hardware compatibility, making the frame a direct drop-in replacement for standard commercial components.
Prepared the design data for low-cost prototyping using functional additive manufacturing before final tooling investment.