I’ve been running static bench tests for heavy-lift multirotor brushless motors used with PX4 autopilot mapping platforms. One recurring issue I observed is permanent thrust drop after long-duration high-load flights.
When carrying survey payloads for 20+ minute continuous missions, motor housing temperature stays above 85°C. Standard N35 magnets gradually demagnetize after dozens of such flights, leading to unstable RPM, increased vibration and shorter available flight time.
I’d like to collect real field experience from other PX4 integrators:
Have you noticed consistent motor performance degradation after repeated heavy payload flights?
What continuous flight duration do you limit to avoid overheating the power system?
Has anyone tested high-temperature magnet motors to mitigate this wear issue?
Hope to compare lab test data with real flight log feedback from the community.
If this were to happen to me, it would identify this as an incorrect motor choice, for the given applicaiton.
I try to choose my motors such that they can endure the longest possible flight, given the airframe configuration.
One thing i would like to mention is that bench testing can sometimes lead to different results, due to the reduced airflow around the motor, and in real flight it might just be fine. Keep that in mind when benchtesting.
Its not usually recommended to operate motor on its peak throttle limit for extended periods, best practice is to make sure individual motor operates on its 50-60% throttle for Drone’s max takeoff weight.
Using Higher thrust motor should solve all your problems.
Same here. Cheaper motors go soft after a while, you can hear it. Higher temp rated ones hold up better. Still wouldn’t push past ~70% throttle on long flights though.
