What are servo motors?
Servo motors, or servomechanism motors, are used to position robotic appendages such as arms, grippers, legs, and sensor mounts. They create other movements where the position is the main factor, unlike the wheel motors (DC motors), where speed is the controlling factor. Servo motors are used where (to some level of accuracy) turning to a specific place might be required. You can use code to control these precise positioning movements or a sequence of them:
![](https://static.packt-cdn.com/products/9781839218804/graphics/image/B15660_10_01.jpg)
Figure 10.1 – A small selection of servo motors
Servos come in many sizes, from the very small at around 20-30 mm (shown in Figure 10.1) to those large enough to move heavy machinery. Figure 10.2 shows some of the miniature hobby servos I use for my robots:
![](https://static.packt-cdn.com/products/9781839218804/graphics/image/B15660_10_02.jpg)
Figure 10.2 – A small selection of servo motors in robots
Now that you've seen where you might use servo motors, we can dive deeper and find out how a servo motor works.