What makes a drone fly? When you are building a DIY drone, what is the most important part for the drone to achieve the best flight time, efficiency, and maneuverability? It is the drone's engine, also known as the drone motor.
Drones fly in the sky, powered by different types of drone DC motors, each with its own unique characteristics and applications. The motor is the power source of the drone, and the flight state of the drone is changed by changing the speed of the motor, allowing the drone to hover, rise, or descend in the air.
For drones, there are two main types of DC motors: brushed motors and brushless motors (BLDC). Brushed motors use physical brushes to commutate the motor, while brushless motors rely on electronic control for commutation.
What are brushed DC motors and brushless motors? How do they work?
Brushed DC motors: These motors have brushes and a commutator inside. The contact between the brushes and the commutator allows the current to switch between the stator and the rotor, driving the rotor to rotate.
Brushless DC motors: There are no brushes and commutators. The magnetic field of the rotor is switched by an electronic controller (usually an electronic circuit with a Hall sensor) to directly drive the rotor to rotate.
Brushed DC motors are the backbone of the small motor field, powering countless applications, and some small toy airplanes also often use brushed motors. Brushless DC motors, mostly using an outer rotor design, are widely used in the drone industry for their low energy consumption, low noise, ultra-long life, and high reliability.
Drone motors are devices that convert electrical energy into mechanical energy. After the drone is equipped with a battery, it begins to power the entire drone, most of which go to the drone motor. The motor of the drone is mainly a brushless motor, one end of which is fixed to the motor seat of the arm, and the other end is connected to the propeller, which generates downward thrust through rotation.
How to choose a drone motor?
When you plan to create a drone yourself, choosing a drone motor is crucial. Pay attention to several factors, motor size, KV rating, drone power requirements, thrust-to-weight ratio, and flight conditions.
The size of the motor is determined by its diameter and height, which directly affects the lift and maneuverability of the drone. The larger the motor size, the larger the diameter, the higher the height, the greater the thrust, allowing the drone to carry a heavier payload. The KV rating of the motor indicates its speed - the revolutions per minute (RPM) per volt of power supply.
How to maintain a drone motor?
The drone motor is a relatively complex electronic mechanical device that is key to maintaining the balance of the drone. Maintaining the drone motor is also a maintenance of your drone.
1. Do not use it in an overheated or overcold environment
Most drones are used in an ambient temperature of -10°C ~ 40°C, on the one hand, considering the lithium battery, and on the other hand, considering the drone motor. Make sure your motor starts working at the right temperature.
2. Avoid moisture from entering the motor
You must have heard that drones are not 100% waterproof, except for underwater drones. Therefore, please pay attention to weather conditions and the protection level of your drone, and try not to use the drone in places with high moisture and rainy days.
3. Check the motor bearings regularly
The way to check the motor bearings is to remove the propeller and drive motor and listen to the sound. Normal rotation without noise, the sound is loud. If the sound is noisy and there is a sound like there is sand inside, it may be that the bearing is damaged and needs to be replaced.
4. Use a drone landing pad
If the environment is dusty, it is recommended to lay a drone landing pad on the ground when the drone takes off and lands. This is because the wind is strong during takeoff and it is easy to roll up some fine sand.
5. Remember to check the motor wear before each use
Since one end of the drone is connected to the drone propeller, foreign matter in the propeller device will cause the motor to get stuck after running, so you can check and deal with the foreign matter blockage before each use.
6. Check whether it is running normally
If the motor does not rotate or makes abnormal noise when powered on, turn off the power immediately.
How to judge whether the drone motor is broken?
Pay attention to the following situations:
- The external structure of the motor is damaged.
- For most multi-rotor motors, if the axial play clearance is greater than 0.5, please replace the motor. (Judgment method: measure the distance from the steel ring to the back cover).
- The motor is leaking.
- The internal resistance of the motor is abnormal.
- The motor stops working/does not rotate completely.
- The motor shakes abnormally, gets stuck, or is slow to respond.
- The winding is burned, the wire is broken, and there is abnormal noise.
Related More: Drone Motor Spinning Wrong Direction Indication
Summary
Brushed motors have the characteristics of simple structure and low cost, but low efficiency and regular maintenance. Brushless motors have high efficiency, long life, and almost no maintenance, but relatively high cost, and more complex structure and control system.
Whether you create a drone for personal entertainment, high-speed drone competition, or commercial projects, choosing the right drone motor can ensure the perfect balance between performance and durability.
FAQ
Do drones use AC motors or DC motors?
Drones usually rely on small, compact DC motors to provide propulsion. The reason for the preference for small DC motors is that they can efficiently convert electricity into mechanical force, which is essential for the lift and control of drones in the air.
What type of motors does Autel use in drones?
Autel Robotics is a leading brand in the drone industry, and its drones use brushless DC motors (BLDC). Autel drones are mostly quadcopters, designed to be lightweight and easy to use.
Which DC motor is best for drones?
The best DC motor for a drone depends on the size, weight, and intended use of the drone. Brushless DC motors are generally favored for their efficiency, lifespan, and higher power output.
How many motors does a drone need?
The number of motors required for a drone depends on its design. As the name suggests, most quadcopter drones require four motors. There are also tricopter drones, hexacopter drones, and octocopter drones, and the motor configuration may vary depending on the different drone designs.
