Servos control the steering in electric and nitro gas powered remote control cars and trucks by means of a little electric motor that rotates a gear attached to what is called a servo arm. The radio control sends signals to the receiver which sends the appropriate current to the motor in the servo to make it rotate back and forth.
The servo is directly connected mechanically to the vehicles's steering mechanism by what is called a servo arm and this linkage ultimately moves the tires left and right. It all happens in a split second so the input from the radio is seen and felt almost instantaneously depending on the quality of the servo used.
Nitro rc cars and trucks also require a servo to control the throttle/brake linkage. Electric vehicles use electronic speed controls to control the throttle and brake but if you are running a mechanical speed control you will need a second servo as well.
Remote Control Cars <- Servos
An introduction to remote control cars and trucks.
RC Car Talk.com <- Remote Control Cars <- Servos
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