The motor used on a robot can depend on a number of factors. What the robot is being used to move, the power needed to do so, and the weight of the robot are all key considerations. Higher power motors require larger batteries, which are considerably heavier and increase the overall weight of robots. The major types of robot motor include continuous direct current (DC) motors as well as stepper and servo motors; each has distinct benefits and disadvantages depending on the robotics application. Voltage, current, speed, torque, and size are major considerations when choosing a motor to make a robot.
For choosing the best robot motor, DC motors are a popular choice because they can run off the power from typical robot batteries. There are many kinds of continuous DC motors to choose from. These robot motors, whether supplied with or connected by the builder to a gearbox, have enough power to support a machine weighing several hundred pounds. Depending on the robot’s torque requirements, gear reducing components might have to be installed which can consequently increase the weight and cost of the project.
If a stepper motor is used with a robot kit, then it is not necessary to use gears to limit power consumption when the robot moves slowly. The motor moves in small increments, so motion that occurs under changing loads may not be sufficient unless additional circuits are added. Servo motors are another kind of robot motor and are typically the least expensive overall. Suitable for angular and rotational motions, they can be used on robots with grips and multi-jointed arms that pick up, move, and place objects. These motors can also be reconfigured for the addition of continuous rotation to the robot’s capabilities.
When choosing the best robot motor, it is important to know what voltage the motor is rated for. Most home-built robots require six to 24 volts, but if operated at any higher voltages, the motor will tend to overheat and stop working. The current the motor draws while operating is important as well as the stall current drawn when it stops rotating. The level of wattage and amount of heat it can withstand must also be considered, while the force of the robot motor, or torque, and its maximum speed also need to be known when building robots. Generally, the higher the torque rating in robotics, the larger and heavier a robot the motor can support.