Why are my FPV drone motors hot — and how to fix it?
Hot motors are a warning sign, but rarely a mystery. It's usually one of two causes: the hardware (KV/props/mechanics) or untreated noise burning energy in the motors. Here's how to tell which.
Check first: hardware and prop choice
Too much prop for the motor (high KV with aggressive tri/quad-blades) draws more current than the motor can shed as heat. Motor screws that are too long and press into the windings, plus worn bearings, also create heat. Stay within the prop range from the motor datasheet before touching the tune.
The most common tuning cause: noise and filters
If the mechanics are clean, heat usually comes from noise reaching the motors unfiltered — motor noise or D-term noise. The derivative term (D) amplifies noise in particular; it shows up as high-frequency jitter in the motor output. An active, effective RPM filter plus dynamic notch is the most effective remedy.
Too much D and too little TPA
Too high a D term sends rapid micro-corrections to the motors that make heat without thrust — try 10–15% less D. For sustained high throttle, TPA helps by lowering the PID gains up top, where oscillation and heat would otherwise appear.
Measure instead of guessing
Whether it's noise or a PID value isn't something you feel at the motor — it's in the log. PIDoctor separates noise/filters from the PID values and shows in the FFT whether your filters actually hit the motor harmonics — so you fix the heat in the right place.