Effects of FPV Drone Frame Materials on Thermal Conditions of Motors Under Extreme Payloads: Experimental and Numerical Analysis

This study investigates the influence of frame material on the thermal behavior of motors and mechanical performance in First Person View (FPV) drones operating under extreme payloads. Two identical 7-inch quadcopters were constructed, differing only in the lower frame section material: carbon fiber-reinforced polymer (CF) or aluminum alloy 6061-T6 (AL). Both drones were subjected to 5-min hover tests with and without a 20 N payload, and their performance was assessed through infrared thermography, vibration analysis, flight log data, and finite element method (FEM) thermal simulations. Under no-load conditions, both frames showed comparable motor temperatures (37–44 °C). With payload CFframe motors exceeded 90 °C, indicating severe overheating, while ALframe motors remained below 60 °C, approximately 30 °C cooler, and demonstrated a more uniform temperature distribution between motors. Power analysis revealed higher consumption for the AL frame drone at no load due to its greater mass, but lower consumption under payload, likely because motor efficiency was maintained. Vibration analysis indicated fewer and lower-frequency resonances for the AL frame. FEM simulations, using boundary conditions from flight data, reproduced the experimental temperature distributions, confirming their reliability for predictive design. The overall results show that aluminum frames, although denser, enhance thermal regulation and dynamic stability in demanding UAV operations, providing practical guidance for defense, search-and-rescue, and other critical applications.