Are Your Quadcopter Motors Overheating? (5 Common Causes and Solutions)

Motor overheating is a common issue that can affect the performance and lifespan of your drone. In this guide, we will explore the main causes and solutions to address this issue, thus ensuring a longer lifespan for your motors and a safer flight experience.

How to Tell if Your Engine is Too Hot

To determine if a motor is too hot, a simple method is to test whether you can hold it between your fingers after flying. If the motor is so hot that it is difficult to touch without burning yourself, there may be an overheating problem that requires attention.

Common Causes of Overheating and How to Fix Them

1. Blocked or Deformed Propeller

   • Description : After an accident or collision, the propeller may become stuck or deformed, preventing the motor from rotating freely.
   • Effect : If the propeller is stuck, the motor requires much more current to try to move, generating heat and also putting the ESC at risk.
   • Solution : In the event of a crash, immediately check the propellers and, if blocked, disarm the drone immediately. Once recovered, replace the damaged propeller and verify that the motor can spin freely before resuming flight.

2. Screws Too Long or Poorly Positioned

   • Description : If the screws used to secure the motor to the frame are too long, they may touch the internal windings of the motor.
   • Effect : This contact can cause excessive heat, as well as abnormal vibrations.
   • Solution : Make sure you are using the appropriate length of screws. If you are unsure, disassemble the motor and check that the screws do not damage the windings.

3. Non-Optimal PID Values

   • Description : In FPV drones, PID values ​​influence the behavior of the drone. Too high a PID value, especially the D term, can cause the motors to work too hard, thus generating heat.
   • Effect : The engine continuously responds to small oscillations, producing an increase in temperature.
   • Solution : Gradually reduce the D term in the PIDs and test flight. If you prefer not to alter the PIDs, you can mount the flight controller with rubber mounts or O-rings to dampen vibrations and achieve a more stable flight.

4. Inadequate Configuration Filters

   • Description : Drone firmware (like Betaflight) uses filters to reduce noise and vibration, but turning them off on a noisy setup can increase heat in the motors.
   • Effect : Inadequate or disabled filters on a drone with a lot of vibration cause the motors to work harder to compensate for gyro reading errors.
   • Solution : If the motors are overheating, re-enable notch filters or other filters in the firmware. Dynamic filters such as those available in recent versions of Betaflight can be useful to keep the motors at a lower temperature.

5. High Outside Temperature and Direct Sun

   • Description : On particularly hot days, direct sunlight can affect the temperature of the engines, especially if dark or black in colour.
   • Effect : The sun can heat the drone's frame and body, raising motor temperatures above normal levels.
   • Solution : In hot conditions, avoid leaving the drone exposed to the sun for too long before flying and try to operate in shaded areas. Consider taking breaks between flights to allow the motors to cool down.

Other Causes and Countermeasures

1. Worn or Poor Quality Components

   • Effect : Components such as worn bearings or low-quality motors can overheat more quickly.
   • Solution : Make sure you use good quality components and regularly check that the bearings are in good condition.

2. Unsuitable Propellers

   • Effect : Propellers with excessive pitch or size require more power from the engines, causing excess heat.
   • Solution : Use propellers recommended for your drone’s motor and ESC type. Make sure they are well balanced to avoid unwanted vibrations.

Conclusion

Overheating motors can be caused by a variety of factors, including suboptimal PIDs, incorrect filter configurations, or poor component choices. Keeping your motors at the correct temperature is essential for good performance and to prevent failure. Use these solutions to quickly resolve overheating issues and ensure your drone is always ready to fly safely.