CHAPTER 27 ■ ENCORE
A robot tends to become fairly wide when you add wheels and couplers directly to a motor shaft with
the motors placed end-to-end in the robot’s body. Even if you are not trying to change the speed, you can
still rearrange the shape of the robot by placing the motors side by side with pairs of gears transferring the
motor power to a different location (see Figure 27-20).
Figure 27-20. Wavy’s gearhead motors and couplers fit parallel, with added gears speeding up the robot and
centering the wheels
Figure 27-19. Assorted gears
Servos
There are four major types of DC motors usually found in robots. Plain DC motors and gearhead motors
were covered in this book. Stepper motors are more precise but require complicated electronics to
implement well. The last major type of motor is the servo.
Servos contain built-in electronics and gearing (see the right side of Figure 27-21) that position the
motor shaft at a specified angle rather than continuously rotating. Servos are often found on model airplanes
and model sailboats to control the angle of the wing flaps or sail.