Brushed and brushless RC motors are the two main types of electric RC car types out there. If you’re a fan of radio control like we are, there’s a good chance you’ve heard of these types of engines before.
But you probably don’t know what the main differences are between them, or if you have to choose between a brushless or brushed electric RC car. Today, we will discuss the brushed vs brushless RC. Let’s dive in.
What is Brushed and what is brushless?
First of all, we are going to differentiate them, because you may have already noticed that we are mixing nomenclatures. Brushless RC cars? Brushless electric motor? Brushed motors? Brushed motors? What the hell are we talking about?
Well, before continuing you must understand the nomenclatures. Thus, we are going to call a brushless electric motor, a brushless motor, and one that has brushes, Brushed.
Once you know how to differentiate the names of electric motors for RC cars, let’s start talking about how they work.
How do RC Brushless motors work? How do the Brushed do it?
Later we will talk about which engine is more powerful, which has a better service life, and which one suits you. But now we are going to talk about the differences at a glance between the motors of Brushless RC cars and Brushed ones.
The difference between brushless motors and brushed motors is that the second use brushes (a kind of brushes) that are connected to a commutator to make the rotor change its polarity. These brushes are in charge of mechanically commuting the current of the motor windings.
On the other hand, a brushless electric motor, as its name suggests, does not have these brushes to change the polarity of the rotor, but the commutation of the coils is achieved electronically by means of a motor controller.
We leave you a video where it is quite visually explained how a brushless RC car motor and a motor with brushes work:
Brushless Electric RC Cars (Brushless)
In brushless motors the coils are located on the stator instead of the rotor. Instead, permanent magnets are placed on the rotor. This design succeeds in eliminating motor brushes.
In addition to the external rotor, a brushless rc motor uses three phases of the drive coil and an additional sensing device to detect the rotor position and drive electronics.
These magnets that we have talked about, make the electric current pass directly through the winding of the housing or the stator, creating an electro magnetic field that, together with the magnetic field of the magnets, generates an intrinsic force that makes the rotor rotate and consequently the motor shaft does as well.
This electronic commutation that is generated in Brushless motors is created based on the position sensors, instead of a mechanical rotary switch as occurs with brushed motors.
Therefore, as this type of motor does not have a brush, no collector or thinner, there will be a single element that will act as a controller so that the rotor rotates whatever its position: the electronic variator.
This electronic variation makes sure that the current that reaches the rotor, whatever the position it is in, is adequate to move it correctly. And how does the variation of a brushless RC truck get to do this? Thanks to sensors placed in the engine itself.
For this reason, the drives used in brushless motors are a bit more complex than those used in brushed ones, since they need to analyze the response and data on how the motor is working in real-time.
The “kV” factor in brushless motors
The “kV” characteristic of the motor of a Brushless RC car is a very important parameter to take into account since it normally appears next to the turns of the motor winding.
Therefore, the kV of a brushless motor will indicate the number of rpm at which the car’s motor is capable of turning for each Volt applied to it.
This has an advantage, and that is that the higher the kV number, the higher the speed of the vehicle. But also a disadvantage, since as the kV increases the torque values will be lower.
You have to find a balance between average torque and speed depending on each and every one of the characteristics of our model. For example, if we have a lightened RC buggy, we are going to find that its engine has quite high kV numbers since it will give it the speed and acceleration we are looking for.
On the other hand, if we have a very heavy RC car, we will try to lighten the kV values so that its acceleration and speed are optimal but not too much so that it provides the torque with good stability.
RC cars with brushed or brushless motors
Unlike brushless motors. These types of motors do have brushes. But this is not the only characteristic that composes them.
They have the casing, which is the main body of which this engine is composed. In it, we find 2 fixed magnets that act as magnetic poles.
In this type of motor, we can also find a rotor, which is a piece with 3 poles that are wound by the winding. This winding is nothing more than a cable that will determine if the performance of the engine of our RC car is good or not. At one end of the rotor, we will see an output shaft, to which the opinion of our car is screwed.
And we have the other end of the rotor, right? Well, there we find the collector. This is a connection point used to transition between positive and negative periods.
The brushes are supported on the commutator and are used to transmit the current. And although it seems like a simple tool, it is very important. Without them, this engine would not work. That is why their maintenance is very important, keeping them always clean and in good condition.
In addition to all these elements, we are also going to find the bell, which is a part that closes the motor, holds the brushes to the rotor and supports the voltage generated by the radiator. And the springs, whose function is to simply keep the brushes in place.
Comparison table between Brushless and Brushed Motors
|S.L||Brushless (brushless)||Brushed (with brushes)|
|Motor||Longer life cycle. Less maintenance.||Minor life cycle. higher maintenance.|
|Efficiency||Greater efficiency||Lower efficiency|
|Output power / size ratio||Optimal||Moderate|
brushed vs brushless RC – Summary
Above we discussed about the brushed vs brushless RC. Can you think of any other things that we missed? Let us know in the comments.