Most quadcopters spin the motors at low speed when armed, making sure your propellers are spinning in the correct direction. Generally, brushed motors are used for the smallest drones, while larger drones and drones will use brushless motors because they can carry the extra weight of the extra electronics. Brushless drone motors also require an electronic speed controller (ESC) to operate.
Autel's EVO series of drones work with brushless motors. When testing the drone, please check the working state of the motor.
Brushless AC Motor
To change the direction of rotation of a brushless motor, swap any two wires connecting the motor to the speed controller. This is achieved by changing the phase sequence of the three-phase brushless motor.
Brushed DC Motor
If your drone uses a DC motor (ordinary aircraft or toy drone), please first check that your propeller is installed on the correct motor. These motors are factory installed and less likely to spin in the wrong direction.
The Drone Flips When it Takes Off
Probably the most common cause of confusion for new pilots, who have built their own drones that flip on takeoff and are easy to fix but difficult to diagnose. This is because there are several different issues that can cause this to happen.
Motor Rotation Direction is Wrong
The flight controller expects each motor to rotate clockwise or counterclockwise, depending on where they are. Check your flight controller manual or datasheet for motor rotation direction symbols and make sure your motors match the configuration of your flight controller.
Incorrectly Installed Drone Propellers
The propeller should spin in a direction that forces the air down, while the concavity of the blades curves down. Check that your propellers are spinning in the correct direction and not upside down.
Radio System Failure
Antenna placement is critical to the success of any wireless system. Power, antenna quality and location, and a clear line of sight are all important for good signal strength. The current Autel EVO drone uses a built-in antenna setup and is no longer displayed on the outside of the drone.
Using an amplifier to increase signal strength results in a significant increase in distance. However, these amplifiers saturate the receiver at close range. Since the receiver is used to such strong signals, any small obstruction in the line of sight can cause the radio connection to fail.
Propellers Fly Out in Flight
As funny as it sounds, this does happen occasionally and can cause significant damage. A few different suppliers offer self-tightening props that will ensure your propeller will never come loose. Secure your bolts to prevent them from loosening during flight.