Servo motors are a staple of hobby and industry robotics. They are highly versatile and can be used as manipulator arms for tasks and as drivetrain motors for lightweight robots.
Often for tasks, one needs controlled positioning. Typical servo motors allow for control of angular position over a range of 180 degrees.
To be used as drivetrain motors, servos can be “hacked” to allow for continuous rotation. This process involves cutting out the positioning circuitry and mechanical stop. Positioning circuitry in servos that operate over a range 180 degrees cannot position the servo over a range of 360 degrees if the mechanical stop is taken out. This means once the servo is hacked, it will operate as a normal motor and lose its ability to set angular position. This also means that hacked servos are plugged into the motor ports of the Proteus, not the servo ports.
The FEH Store sells two servos: the FITEC servo (higher-torque) and the Futaba servo (lower torque). It is advised to use the FITEC motor for drivetrains. If either of these servos do not fit your needs, remember that servos are a very common toy/robot hobbyist part, and numerous, cheap options can be found online.
For wiring a servo as a standard servo motor:
For wiring a servo as a drivetrain motor: