RC Car Electric Motor

Stuff That Every RC Electric Car Owner Should Know

RC car electric motor is one of the most significant parts of an electric radio controlled car. The power of the car depends upon the power that the motor is able to generate.

Given the size constraints of the motors because of sleek rc electric cars, current technology does a good job by providing us with motors that deliver immense power from their small casings. Just imagine the power that would be needed to propel a 5-6 pound rc car to a speed of 70+ miles per hour.

What is a rc car electric motor like?

An rc electric motor would generally comprise of the following parts

  • An external can like housing
  • 2 powerful magnets inside the can
  • Armature core made of iron
  • Copper windings
  • Graphite brushes attached to the commutator

Electric Motor in Detail

Brushes and Springs

Performance requirements of electric rc cars vary within a wide range, so does the type of brush and spring combination in order to cater to the varying amperage needs. Nowadays brushes are made up of graphite composites coupled with metals like copper and silver. Copper and silver impart conductivity to the brushes.

As a thumb rule off-road vehicles require low amperage which is obtained by employing low conducting brushes and high weight springs. On the other hand small on road vehicles need high amperage which can be obtained by using high conducting brushes and low weight springs.

The conductivity of the brushes is controlled by the amount of Silver or Copper in it.


Commutator is located at one end of the armature. It consists of three segments. The brushes are in contact with two of the three segments of commutator and the armature windings at any given point of time.

When current is passed through the brushes into windings the armature becomes an electromagnet. This new formed electromagnet repels against magnetic field inside the container. This makes the armature rotate.


Timing as the name suggests refers to the time in which the brushes change contact from one armature segment to another. Advancing the tine will increase the revolution per minute or RPM as you better know it. Retarding it will mean reduction in RPM but gain of torque.


Turns refers to the number of times the copper wire has actually been revolved around the armature. The higher the number of turns greater is the torque generated and hence greater is the power delivered. However that also means less RPM rating for your rc car electric motor. Generally less turns are preferred for making the rc car run faster.


One or more copper wires are usually wound around the armature. The number of wires that are wound around the armature is called the wind of the motor. Sometimes the wind is increased in order to compensate for the torque lost by reducing the turns.

Motor Gearing

Putting the correct gears in place holds the key to any racer’s success. So when we are discussing about rc car electric motor it’s good to pull in various gears into discussion. The objective is to know the different types of gears that your car has and understanding their usage.

There is a small gear attached to the motor called Pinion Gear that transmits power to another gear attached to the transmission system. The gear attached to the transmission system is called Spur Gear.

Smaller pinion gear means high acceleration and relatively low maximum speed. This comes in handy when you are into the racing track that involves a good number of turns or sharp turns to be specific.

In turns you need to get into slower speed and immediately after negotiating it you got to get back to your top speed. This is where you will need high acceleration. Having a small pinion gear ensures that the acceleration is top notch.

On the other hand when you race on oval or straight tracks with longer patches that need constant speed its good to have a larger pinion gear. This will give a higher maximum speed needed for such races. The acceleration in this case will be slower but then the maximum speed carries more importance than the acceleration.

Brushless Motors

Brushless motors are more or less becoming the norm nowadays among the electric rc fraternity. The advantages being that they bring up respite from continuous maintenance that brushed motors demanded.

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