Understanding the factors that affect the quadcopter motor direction will help pilots understand UAV ownership.

Factors such as air pressure, propellers, and design significantly influence the quadcopter motor direction.

The technique of a quadcopter motor direction is different from that of a helicopter or aeroplane. A lot of quadcopters use the drone reverse motor direction working concept.

However, they use a principle that is not much different, namely the Bernoulli principle. This principle is the main principle of an object flying in the air.

Once upon a time, there lived a genius man named Daniel Bernoulli. His genius peaked when he discovered the unique relationship between speed and pressure.

This principle of genius is related to aerodynamics; the faster it flows over the wing, the lower the pressure on that portion of the wing.

The genius principle of aerodynamics is called the Bernoulli principle. The lower pressure is in the area of the faster-flowing air. Conversely, higher pressure is in areas of slower flowing air.

This pressure makes the air above the wing move faster and the air below the wing slower.

Higher pressure under the wing pushes the wing up; no matter what the object is, as long as this principle is adhered to, an entity will fly.

Therefore, drones, Boeing 747s, RC planes, and so on use the Bernoulli principle.

## How Quadcopters Work

There are four motors at all four ends of the body frame with a quadcopter working principle in a quadcopter.

The quadcopter motor direction is made so that the movement of one motor moves against the torque of the motor on the other side.

That motor is against each other, which gives the effect of flying to the UAV.

Of course, it’s a simple principle. For the quadcopter motor direction to hover in the right place, it is necessary to ensure that:

- All quadcopter motors rotate at the same speed.
- The rotational speed of each quadcopter motor must be sufficient to make the quadcopter generate ‘lift’. Because of its weight, the engine tends to put out full power. However, it should not be too much so that the quadcopter remains stable, moving up.
- The effect of torque on the main-body quadcopter of each motor must be cancelled. If not, chances are the quadcopter is prone to yaw.

Drones use rotors for propulsion and control. You can think of the rotor as a fan because they function pretty much the same.

Of course, all the forces come in, which means that as the rotor pushes the air down, the air pushes up on the rotor.

The principle is the basic idea of lift, which is lowered to control the upward and downward force. The faster the rotor turns, the greater the lift, and vice versa.

Now, drones can do three things in a vertical plane: hover, climb or descend. Or, you will know how a drone moves forward and backwards.

The net thrust of the four rotors pushing the drone up must equal the gravitational force pulling it down to hover. So what about when moving up, what the pilots call climbing?

The trick of those quadcopter thrust equations is straightforward: increase the thrust (speed) of the four rotors so that an upward force is not greater than its weight.

After that, you can reduce the thrust a bit, but now there are three forces on the drone: weight, thrust, and air resistance. So it would be best if you still had a giant thruster than hover.

Descending requires doing the opposite: Reduce the thrust (speed) of the rotor so that the net force drops. Understanding this quadcopter motor direction principle helps you get a suitable motor.

## The Right Motor Design For Your Quadcopter

It’s easy to choose the suitable motor for your quadcopter if you understand the basic principles of quadcopter motor direction.

The first thing to ascertain is what the total weight of the quadcopter is? And what is the body-frame size of the quadcopter?

To be able to measure the total weight of the quadcopter, you can start by estimating it.

However, make sure all hardware and quadcopter components are accounted for. Examples include counting body-frame, flight controller, PDB, drone propeller position, cables, motor, battery, gimbal, camera, and payload.

Suppose you already know the size of the body frame. In that case, this means that the fundamentals of primary drone propellers are explained and determined correctly. But not technically, like how to install drone propellers.

Once you know the size and weight of the propellers, you can already know how much thrust the quadcopter must produce.

Knowledge of thrust can help pilots make calculations of thrust to take off and fly a quadcopter.

The general rule is that the motor must be strong enough to provide twice the total weight of the quadcopter.

If the motor thrust is too small, the quadcopter will not respond ideally to pilot control. Even quadcopters can have problems taking off or flying.

As an example of the calculation, there is a quadcopter with a total weight of 1kg.

The aggregate thrust generated by the motor at 100% throttle must be at least 2kg or 500g for each quadcopter motor direction.

That amount of pushing force gives the pilot better control. Plus, it will increase the possibility of adding additional loads or heavier loads in the future.

Brushless motors are usually grouped with a four-digit number – such as **##. The symbol “**” is the stator width and “##” is the stator height. In essence, the more comprehensive and taller the motor, the bigger the number and the more torque it can produce. Or you can also search for a drone motor size chart on the internet and match it to your needs.

KV is another crucial parameter to know in quadcopter motor direction. KV is the theoretical calculation of the motor RPM when the voltage is 1 volt without load.

For example, a 2300KV motor with a 3S LiPo battery (12.6V) will produce a rotation of 28980 rpm (2300 x 12.6V = 28980).

However, the rpm will not be that high once the propeller is installed due to the support resistance.

The higher the KV size, the faster the propeller rotates with low torque. Conversely, the lower the KV, the higher the torque with slower propeller rotation.

Therefore, finding a balance between rpm and torque when buying a motor and propeller is significant.

If the balance is not found, the drone will experience currents and produce overheating. And it would be best if you went back to the basics of quadcopter motor direction principles.

Source:

- https://www.dronezon.com/learn-about-drones-quadcopters/how-a-quadcopter-works-with-propellers-and-motors-direction-design-explained/
- https://www.droneybee.com/quadcopter-blade-rotation-lift/
- https://www.rotordronepro.com/guide-multirotor-motors/