The most important part of every multi-copter is its electric FPV drone motors. A slight change in their specification could bring a lot of variations on the flight of the drone. Therefore, you need to choose the right motor for your drone. Choosing the right drone motor would have a direct impact on the thrust and total power of the drone. However, it is not an easy process, especially if you are a non-technical person. Therefore, in this article, we would discuss some important points about FPV motors. From their basic working mechanism to the common types of the motor everything is discussed in detail for your understanding.
The key concept behind the operation of every drone motor is electromagnetism. Every brushed and brushless motor works based on electromagnetism. Both motors use electromagnets to convert electrical energy into kinetic energy. Electricity supplied to the electromagnets helps them to generate a magnetic field around them. This temporary magnetic field interacts with the permanent magnets of the motor to produce a combination of attraction and repulsion. All this results in the rotation of the motor shaft.
You might be wondering if both brushless and brushed motors work on the same machine then what is the difference between them? well to understand them completely you need to completely understand their working mechanism. However, the biggest difference between them could be found in their names. One contains brushes and the other motor completely brushes free.
Brushed FPV Motor:
Brushed motor’s internal operational mechanism is very different from brushless FPV motors. Every brushed motor contains a stator that produces a permanent magnetic field around the rotor. The rotor is an electromagnet that is influenced by the stator of the motor. Pair of brushes found inside the motor is connected with a commuter ring found at the bottom of the rotor. The commuter ring is responsible for periodically reversing the current follow through the rotor. This alternation of polarity provided by the commuter ring produces an uninterrupted revolution of the rotor. You might be more interested in the advantages and disadvantages of the brushed motor. Therefore, we have listed some important points for you to make the right choice.
Pros and Cons:
- The working mechanism of the brushed motors provides excellent protection to the delicate components.
- They have low efficiency due to the greater thermal insulation found in its internal mechanism.
- Reversing the rotation of the rotor is only possible by inverting DC power input polarity.
- With the direct connection between brushes and the commuter, their longevity is slightly less then brushless motors.
- They are the best fit for small size multi-copter that have less weight and require simple driving techniques for the stability of the flight.
Brushless FPV Motors:
It is obvious from the name that these motors do not have any kind of brushes. A brushless drone motor can be divided into two main components; the stator and the rotor. The stator in a brushless motor is the central unit and the rotor is mounted inside it. The stator produces a temporary magnetic field with a network of electromagnets. The rotor of the brushless motor contains a collection of permanent magnets. These permanent magnets are placed in such a way that they interact with the stator electromagnetic field. This interaction results in the attraction and repulsion between the stator and the rotor magnets and thus a rotational motion of the shaft is achieved. With the use of ball bearings during the assembly of the motor smooth revolution of the shaft is made possible.
Pros and Cons:
- Brushless motors could not be used directly and they have to be wired with the control electronics to eliminate the need for brushes and commuters.
- Due to the absence of brushes, the have a very long-life span.
- They have a higher efficiency than the brushed motors.
- If you are looking for higher power outputs and efficiency is a priority then they are the best fit.
The next important thing you need to know before buying any brushless drone motor is size identification. Every brushless motor size could be identified by its four-digit code. It contains the dimension of the stator in millimeters, for example, 2206. The first two digits of these numbers give the diameter of the stator. Under this example the stator diameter is 22mm. the last two digits of the code describe the height of the stator. Therefore, the 06 in the example tells you that the stator is 6mm tall. However, you need to remember this code has nothing to do with the external dimension of the motor.
Similarly, the size of a brushed motor could be identified by a simple two-digit code. For example, a two-digit code 6*15 for brushed motor defines the diameter and height of the exterior can in millimeter. The first digit tells you about the diameter of the can which is 6mm in this case and the second digit 15 tells the height of the can.