RC Servos In Detail

Servo motors are the heart throb of radio controlled cars. RC servos are usually referred to as servo motors and are controlled by a radio held at a remote location. Servo motors control the throttle, brakes, steering of rc cars and in some cases engage forward or reverse gears. RC radio servos are wired into radio receivers and are commanded through pulse width modulation.

Servo motors contain motor, gearbox, controlling electronics and feedback mechanism. Servo motors usually have three wires, positive, ground and control. The control wire communicates the angle to which the servo motor should turn. The control signal for servo motors is a pulse, and the duration of the pulse determines the position of the servo motors output.

Types of Servo Motors

There are several types of servo motors on the market. The most commonly available servo motors on the market are the range from Futaba. These include high tech digital servo motors. The regular servo motors used in radio controlled cars is small and inexpensive. These servo motors are usually made from plastic and have plastic gears. Servo motors also come in mini, standard and large scale sizes. Ready to run radio controlled cars come with servo motors attached but servo motor modifications can be performed.

The range of servo motors from Futaba includes digital servo motors which are fast gaining popularity. Digital servo motors offer two advantages over conventional analog servo motors namely speed and holding power. The microprocessor that controls a digital servo motors position is six times faster than the analog one. Digital servo motors offer higher resolution that reduces dead band and thereby provides ultimate control. Digital servo motors also produce constant torque and have considerably more holding power. One disadvantage of digital servo motors is that they consume more battery power, so when used in a rc nitro car one must use a high capacity NiMH pack.

While Futuba offers a diverse line up of servo motors with around 11 digital servo motors companies such as Hitec and Airtronics are not far behind.

Servo Motors Mods

Usually rc servo motors come in standard sizes and have similar control schemes. Unlike other servo motors rc servo motors are constrained from full rotation. RC servo motors are restricted to a limited rotation of 180 degrees or less. Standard servo motors such as the Futaba S148 can undergo mods which are designed to make it rotate a full 360 degrees. The most brutal servo motor mods are carried out by opening up the servo motor. In this scenario once servo motors are opened up the electronics are removed, the power lines brought out and the potentiometer is removed or modified. The potentiometer of servo motors can be modified to rotate a full 360 degrees. Servo motors can also undergo further modifications designed to convert a standard servo motor into a gear head motor.

Digital servo motors such as Futaba’s S9254 are a great buy and can be used to upgrade nitro rc cars.