Brushed vs Brushless RC Motors Header

Brushed vs Brushless RC Motors

Brushed and brushless motors are the two main types of motors for electric RC vehicles. If you are an RC fanatic, there is a good chance that you have heard of these before, but probably have no idea what the differences are or if you should choose one over the other. In this article, you’ll learn everything you need to know about brushed vs brushless RC motors.

How do these two types of motors work and what is the difference?

You may know that one is more powerful than the other. Or that one runs better than the other. But do you actually know the real differences between brushed and brushless motors?

The simple answer is that the former uses brushes and the latter does not. However, it is a little more complicated than that.

Technically speaking, brushed and brushless motors apply a similar working principle.

An electromagnetic field is created when the winding of the motor receives a current supply. The winding then pushes and repels against a permanent magnet to cause the shaft to turn.

The energy is then transferred from one winding to another that ultimately causes the motor shaft to spin continuously.

Here is a nice video to simplify things before we dive right in.

Brushed DC Motors Explained

As mentioned earlier, brushed motors have brushes inside them.

Brushed RC Motor Diagram

These brushes are typically made of copper, silver or graphite and are used to convert electricity into motion. They make contact with a mechanical rotary switch called a commutator and deliver an electrical current.

When the current is passed through the windings, a magnetic field is created, repelled and attracted, which consequently causes the armature, also known as a rotor, to rotate.

For brushed motors, the windings are located on the rotor and the magnets are on the stator.

The Pros of Brushed Motors

One of the advantages of brushed motors is they are fairly simple and reliable. They provide a basic two-wire control. This makes it ideal for entry-level cars and new users.

Even with their simplistic control, this type of RC motor gives more power for tight, tactical driving.

This means that it is easier for brushed RC cars to maneuver through rough terrains compared to RC cars with brushless motors because they have less or minor external components.

In addition to their simplistic control, brushed motors are also great for beginners because the prices of brushed motors are far more affordable when compared to brushless motors.

This may be because they lack electronic elements, or for reasons that you can read about below.

DC brushed motors are also highly configurable. You can modify them to get the exact speed that you want with the voltage that you use.

If you’re considering getting an RC with a brushed motor, the Traxxas Slash 2WD or the Traxxas Bandit are excellent choices.

The Cons of Brushed Motors

The main disadvantage of brushed motors is their low power efficiency. In general, the efficiency level of a brushed motor is between 75% and 80%. This is lower than brushless motors which have an 85% to 90% efficiency level.

The brush design explains this reduced power level. The mechanical limitation of the brushes causes the motor to offer lower speed range than the brushless.

To add to that, there is a lot of electrical and electromagnetic noise due to the constant switch of the commutator, brushes and shafts. Due to the perpetual contact of the elements inside the motors, heat loss is high and the rotational force is less.

Another negative of brushed motors is that the brushes can wear out after a while, so periodic repairs and replacements are necessary.

This is minor in the overall scheme of things, but it is something to consider.

Brushless DC Motors Explained

Brushless DC motors, also known BLDC motors, BL motors, or ECMs (Electrically Commutated Motors), are constructed differently.

Brushless RC Motor Diagram

The windings are located on the stator instead of the rotor, and the magnets are placed on the rotor. This unique design eliminates the needs for brushes all together.

Besides the external rotor, a brushless motor uses three phases of driving coil and an additional sensor device to sense the position of the rotor and the drive electronics.

It also makes use of an amplifier that is triggered by an electronic device such as an optical encoder to create a magnetic field inside the motor.

As you can see from the explanation above, electronic commutation with brushless motors is created based on the position sensors instead of the mechanical rotary switch.

The Pros of Brushless Motors

While brushed motors tend to deteriorate quicker and not last as long, brushless motors are quite the opposite.

Brushless motors have a longer lifespan since there are no brushes inside the motors to wear out.

Therefore, you can expect less maintenance, less problems, and less cash to fork over in the long run.

There are no brushes to clean or to replace in a brushless motor. The only thing that you might need to do is to maintain the bearing. This just requires a periodic lubrication to keep it in check.

The best part of a brushless motor is that they typically can run for five to six years without any problems whatsoever.

When we compared the weight of the motors, this type of electric motor is relatively smaller and lighter. It does not put a burden on your vehicle, so you can improve your speed and handling capability quite significantly.

Furthermore, a brushless motor provides more power and longer run times than an equivalent-size brushed motor.

This is because there is no mechanical brush limitation on this type of motor. Brushless motors are also known to be able to deliver higher torque at variable speeds.

In regards to the efficiency aspect, brushless motors have low electric noise.

The heat loss is also very low, which translates to a higher movement for the same amount of electric that you feed to the brushed motor.

If you’re considering splurging on an RC Car with a brushless motor, the Traxxas X-Maxx or the HPI Vorza Flux won’t do you wrong.

The Cons of Brushless Motors

Price wise, brushless motors are flat out more expensive.

This is due to the complex control and the use of the ESC (electric speed controller).

Despite being pricey, we believe that brushless motors provide a much longer-term value for your money because they requires fewer repairs and replacements over the years.

The only other disadvantage of brushless motors is that they offer less load speed control. It makes driving on a rough terrain a bit difficult and challenging compared to the brushed motor.

Brushed vs Brushless RC Motors – Which One Should You Choose?

So the big question is which one is right for you, or which one should you choose?

Brushed

If you don’t necessarily need fast speeds and maximum power from your motor then a brushed motor would be ideal for you.

Let’s say you just need to do crawling and require occasional speed boost at 5mph to 10mph. Then brushed motors are just fine for you.

They are also a great option for beginners who need ample power at a lower price.

Brushless

However, if you need to go faster than 15mph and would like to have some power efficiency, the brushless motor is the best bet for you.

Brushless motors are a great option for experienced racers who need to have more speed from their cars or hardcore bashers who just want to raise all hell with their RC vehicle (If this is you then you might just want to consider the alternative gas or nitro RC vehicle instead).

Upgrading your motor

An alternate option if you have a car you already like but want a brushless motor, is to upgrade the motor only.

This works in most cases, but make sure to do your research first. And also remember that if you are considering upgrading your RC vehicle to a brushless motor, you will also need to upgrade other features in order to support the brushless motors.

For example, you will also need to get the brushless ESC, and the battery will need to be replaced from NiMH to LiPo.

You’ll also need the new battery charger as well as other safety accessories.

So what do you get after the brushed-to-brushless conversion?

You will experience enhanced performance in your RC vehicles regarding the speed, suspension, steering, responsiveness and more!

Source of Diagrams

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