Drones: What Are Rotors And What Do They Do?

To choose the first drone, we will have to know how to choose the engine. This type of choice will fall on the purpose for which we are going to use the device. If we had to choose a racing drone, to participate in FPV racing, we will have to choose it based on the maximum speed. While, if the purpose for which you use the drone is to mount it on an action camera to shoot from above, you will need more control and stability. In this article, let’s see what rotors are and the characteristics of drone motors.


The Drone is a radio-controlled aircraft that allows it to be used in various applications. It can be used for recreational purposes or for professional applications such as aerial video shooting, surveys, territorial control, and much more. Drones are equipped with multiple rotors, usually, they can be three, four, six, or eight rotors. The number of rotors gives the name of the category to which the drone belongs:

  • Tricopter, three engines;
  • Quadcopter, four motors;
  • Hexacopter, six engines;
  • Octocopter, eight engines.

The difference between these types is the load that the drone can carry during flight. With the exception of tricopters which are mainly used for recreational purposes, with a small quadcopter you can fly a small video camera mounted on a video stabilization support, called a gimbal, to make valid video footage.

Brushed And Brushless Motors

Brushed motors are brush motors, i.e. we are talking about the “classic” motors that are mounted on toy drones for children. The internal rotor is wound by an electric wire and rotates around magnets with opposite polarity. When the system is powered, the winding will generate a magnetic field that produces the rotation of the motor itself and of the propellers to which it is connected. This type of engine is very economical. They are very simple to equip and perform well in takeoff and landing, and in vertical movement. 

Brushless motors are more suitable for professional drones since they guarantee a greater number of flight hours and allow greater energy savings, compared to those of the previous category. In this case, the magnets are fixed on the rotor, while the windings are fixed and outside. There are three magnetic poles, instead of two, and they are powered in pairs to give current to the windings. This type of motor wastes less energy is more powerful and requires less maintenance.

Characteristics Of Drone Motors By Weight And Size

The weight and size of quadcopters greatly affect motor choice. And you need to pay close attention to the weight. In fact, if the weight is not calculated correctly, the drone will not even be able to gain altitude. The engine must be able to give double the thrust to the drone, in a weight/power ratio that is 2:1. Big or small, it’s the weight that counts.

1. Drone Components

Now let’s see what the drone is made up of:

  • The frame can be said to be the skeleton of the drone. The size of this structure, which is made of metal, must be weighted in a very technical way, it must support all the loaded weight.
  • Batteries are the real defect of the drones in circulation, as the autonomy only reaches up to 40 minutes of flight.
  • Flight controller, this is the onboard computer that records flight data, then combined with both the hardware and software system is able to “orchestrate” the drone.
  • A remote control system would be the radio control and receiver that interfaces with the Flight controller.

2. Curiosity

Therefore we can say that even for drones and the engine it is a matter of balance, the right combination of engine, size, and propeller is needed. This is to ensure that our drone is efficient, that it allows us the correct flight times, and that the flight experience is pleasant. We will have to look for an engine and calibrate the power based on the operations that we have to make the drone perform. Always pay attention to the noise of the engines, under penalty of noise pollution.

3. Push

To fly you need a system capable of counteracting the force of gravity, and therefore the weight of the aircraft. The propellers of a drone are used for this task. The propeller, or rotor, is that fluid machine capable of generating a force. That is, a quadcopter doesn’t need to be in motion to get the thrust needed to maintain flight, since the propellers provide it. The force exerted by a propeller is called thrust. The drone can have various types of propellers:

  • fixed pitch propellers, the thrust depends on the angular velocity and the density of the fluid in which it operates: the faster the propeller rotates, the more it generates thrust.

4. Single Rotor Drone

In this case, you have a single rotor design, so inside just one rotor, while the other will be a tail rotor which simply helps provide control.

5. Tricopter

There are three different types of powerful motors inside a tricopter, three controllers, four gyros, and only one servo. Motors are positioned at each end of three arms and each arm holds a position sensor. A tricopter manages to stay stabilized on its path.

6. Quadcopter

When a multirotor is designed with four blades then it becomes a quadcopter. These drones are usually controlled by specially designed brushless-type DC motors. Two of the motors move clockwise, however, the other two go counterclockwise. This will help perform a safe landing for the quadcopter. The battery for such devices is lithium polymer.

7. Hexacopter

The hexacopter can be used for many applications, very powerful with its 6-motor mechanism where three work in a clockwise direction and the other three move in an anti-clockwise direction. Hence, this type of drone is capable of obtaining higher lifting power.

8. Octocopter

Octo means eight; therefore the octocopter will be equipped with its powerful eight motors which transmit power to 8 functional propellers. This aircraft of course has high capabilities compared to other drones, and it is also very stable. You will enjoy stable movie recordings at any altitude. These drones are especially used in the world of professional photography.

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