Brushed And Brushless RC Motors

When it comes to electric RC model motors, there is a wide variety in the style and power of the motors available to the hobbyist. By understanding how these motors work, you will be more knowledgeable about the motors available for RC cars. Then you will be able to easily select the electric RC motor that is best suited for your particular RC vehicle and style of driving.

There are basically two types of electric RC model motors available to hobbyists. The brushed electric motor is the first type and it has been around since the beginning of the hobby of driving RC cars. This venerable motor provides a tremendous amount of power and performance for RC cars. The brushless electric motor is the other type of motor available for hobbyists. This motor is a relatively recent development in the hobby of racing RC cars, but it is considerably more powerful than the traditional brushed electric motor. Also the added advantage of the brushless motor is that it is a motor that is much easier to maintain than a brushed RC motor. Now that we have discussed the two electric motors that are available, let's look at how each one of them work.

How Brushed Electric Motors Work

The venerable brushed electric RC model motor has been the mainstay of the RC car hobby for many years. This motor is basically composed of two major parts. The outer or stationary parts are what is visible when the motor is assembled. The inner or rotating parts are the section of the motor that work to transition the electrical current to motive power in the electric RC car.

The stationary parts of the brushed electric motor are made up of the magnets, brushes, springs and brush hood. These parts or collectively called the "stator". The outer casing of the brushed motor is referred to as the "can". These parts work together to transmit the electrical current to the spinning parts of the RC motor, which in turn changes the electrical power into the rotating motion of the motor that moves the car.

The rotating parts of the brushed motor consist of the armature, windings, and commutator plates. These parts comprise the part of the motor that is referred to as the "rotor". The purpose of these parts is to convert electrical current that comes from the stationary parts into what is needed to get the car moving in a process called commutation.

The more turns a brushed motor has means that the motor will be slower, but requires less maintenance by the hobbyist. Lower turns in a brushed motor means that the motor will be faster and have more power, but it requires more maintenance. In the end, it comes down to finding a motor that balances speed with maintenance.

How Brushless Electric RC Model Motors Work

Brushless electric RC model motors work in a process similar to a brushed motor except that they are constructed in the reverse of a brushed motor. In the brushed motor, the motor's magnets are wrapped around the motor's armature. In a brushless motor, the magnets are permanently fixed to the side of the "can". The motor's armature is then polarized to spin in a cycle of attraction and repulsion from the magnets that are mounted around the armature. Sometimes a brushless motor will have sensors attached to the side-mounted permanent magnets that send signals to the electronic speed control, which determines the car's speed.

Brushless motors provide speeds and power much more efficiently than brushed motors. The reason for this is that there is no physical contact in the motor other than with the ball bearings on which the rotating armature spins. In a brushed motor there is a lot of friction that reduces the overall power of the motor. Also there is no spark in the commutation process in a brushless motor like there is in a brushed motor. This means that the electrical interference is greatly reduced. Thus, the brushless motor is much more efficient and cooler operating than a brushed electric motor.

About the only drawback to a brushless electric RC motor is that it is considerably more expensive than a brushed motor when you are first starting in the hobby. That starting cost though is soon recovered because you are not having to spend time and money doing considerable maintenance to the motor with replacing brushes, springs, or armatures like you will with a brushed motor. When it comes to the maintenance of a brushless motor, about all you need to do is keep it clean of dirt and grime with a few alcohol wipes and alcohol soaked Q-tips.

Power Sources for Electric Motors

Basically there are four main types of batteries that provide the power for electric RC model motors. The first type of these batteries are Ni-Cad or nickel-cadmium batteries. These batteries are some of the oldest designed batteries found in RC cars. They are easy to charge but have the drawback of developing a memory which keeps them from fully charging. The next type is the Ni-MH or nickel metal hydride battery. This type has a higher charging capacity than the Ni-Cad, however they are very easy to damage if they are overcharged. The third type of battery is the Li-Ion or lithium ion battery. This type has about twice the capacity of a Ni-Cad battery, but it is considerably more expensive than either of the previous battery types. The final type of battery is the Li-Po or lithium polymer battery. This type is the most powerful of any RC battery but has the drawback of becoming very dangerous if overcharged. Overall, the important thing to remember about any battery system is to follow the charging and use instructions that come from the manufacturer on its use in your RC car.

Now that we have looked at how the motors and batteries of RC cars work, you are better prepared to select electric RC model motors for your car. Then you will be able to get out on the track and fully enjoy everything the hobby has to offer. Perhaps the most enjoyable thing of driving RC cars is winning a race with a motor that you have chosen and learned how to get the best performance from.