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Servo motors are simple components that help add precision and automation across various applications in both the industrial and hobbyist spaces. Here’s everything you need to know about servo motors and where you can get your own high-quality components.
What is a Servo Motor?
A servo motor is a highly precise motor that uses a feedback system and external controller to provide hyper-accurate rotational and linear placement. It combines a compatible motor with a controller and sensors to create a precise actuator perfect for applications that require perfect placement and smooth movement.
How Servo Motors work?
Servo motors use electricity to create mechanical movement. A servo motor is made up of a few individual components including a motor, a sensor, and a controller. Here’s how a servo motor works.
A controller first sends a pulse width modulation signal to a sensor within the servo motor. Controllers can be manually controlled by humans or digitally controlled by computers.
The pulse width modulation signal is programmed to communicate the precise amount of electrical current needed to move the motor to the desired position. The width of the pulse determines the position and direction of the motor.
Once the sensor receives the signal it sends an electrical current from the power source into the motor. The motor then rotates to the precise position dictated by the amount of current it receives which moves the gears connected to the output shaft. This moves whatever mechanism, usually an arm, into the exact position needed to complete the task.
The final gear that controls the mechanism is often connected to a potentiometer that recognizes when the mechanism has reached the desired position and turns the motor off keeping the mechanism in the precise desired location.
Servo motors can serve simple purposes like moving the arm of a small robot back and forth. They can also serve extremely precise and complicated purposes like moving the cutting device on a CNC machine, automating packaging, and even controlling components in outer space.
What Types of Servo Motors?
There are five types of servo motors that all come with their own sets of advantages and disadvantages. The type of servo motor you need is highly dependent on the application of the mechanism, the environment in which the mechanism will operate, and your budget.
DC Servo Motor
DC Servo Motors are servo motors controlled by the frequency of the electrical current provided by the controller. DC servo motors are the oldest kind of servo motors and can be found in a variety of hardware that requires both linear and rotational movement. DC servo motors are fast and accurate and are especially responsive to start and stop commands. DC servo motors are most often used in small devices and are generally more affordable than other servo motors.
AC Servo Motor
AC servo motors are a more dynamic type of servo motor that can be controlled by both frequency and voltage. This variability allows AC servo motors to be used with multiple control avenues. AC servo motors are beneficial because they allow for more variability in their applications. AC servo motors are slightly more expensive and are more frequently used for industrial applications.
Positional Rotation Servo Motor
A positional rotation servo motor is one of the most common types of servo motors used in manufacturing. This is a closed-loop system that allows for the drive shaft of the motor to move precisely within 180 degrees. These servo motors rotate that shaft to a specific position based on the pulse width signal provided. Positional rotation servo motors are frequently used in toys, autonomous vehicles, and aerospace applications.
Continuous Rotation Servo Motor
Continuous rotation servo motors allow for the shaft to move 360 degrees in either direction for sustained periods of time. This is an open loop system where the direction and speed of rotation are controlled by the signal received from the controller. These mechanisms are far less precise than closed-loop systems but have many applications when it comes to controlling wheels, conveyor belts, and any other task that requires continuous rotation.
Linear Servo Motor
Mostly used in CNC machining, a linear servo motor contains additional gears that allow the motor to move back and forth across a surface instead of rotating.
Applications of Servo Motors
Servo motors have a variety of applications in both the hobby and industrial spaces. Here are some of the tasks that servo motors can be used for.
Hobby Applications
Small servo motors are used in hobbies that require precise movement. In hobbyist applications, servo motors are most often controlled manually through a wireless controller. Here are some instances where you may see servo motors in some popular hobbies.
Remote Control Vehicles
Servo motors are often used in remote control vehicles. A servo motor is connected to the front axle of RC cars and is used to control the RC vehicle’s steering. The handheld remote control is the controller that tells the servo motor which way to rotate. Turning the wheel on the controller or moving the joystick controls the frequency received by the servo motor. This frequency then turns the axle and the wheels to their precise location.
Robotics
Servo motors are used in robotics to control the movement of joints as well as grasping instruments like hands or claws. Servo motors can precisely position any moving arms by positioning the angle of the joints based on the pulse of the input signal.
Servo motors can also be used to close robotic hands or claws by altering the rotation of the fingers from an open to a closed position. These applications are used by both hobbyists and industry to control the movement of many robotic mechanisms.
Industrial Applications
There are countless industrial applications for servo motors both big and small. Whether servo motors control the precise positioning of tiny mechanisms or are moving heavy objects around, these components are widely used in industry.
CNC Machining
Servo motors are used in CNC machining to move the cutting instrument across the cutting surface precisely. The servo motor in a CNC machine receives a signal from a computer that programs the positions and movements of the servo motor to create accurate cuts on the machined material.
Autonomous Cars
Autonomous vehicles and driverless cars use servo motors to steer. Much like the smaller application of remote-controlled cars, autonomous vehicles use servo motors to turn the axle to make precise movements on the road.
Instead of being controlled by a handheld device, these servo motors are controlled by a complicated array of computers and sensors. These sensors analyze the road and send signals to the servo motors to perform safe and accurate maneuvers.
Packaging Machinery
One of the most popular uses of servo motors in manufacturing plants is in packaging machinery. Packaging machinery, much like the name suggests, is used to safely and efficiently package goods that are to be shipped out to customers.
Packaging machinery uses larger servo motors to control the movement of conveyor belts as well as components that move and fold packaging materials.
Aerospace Engineering
Servo motors are used in a variety of aerospace applications that require incredibly precise and smooth movement. Servo motors are used to open and close flaps and vents that are vital for accurate navigation through space.
How to Control a Servo Motor?
Servo motors are controlled through pulse width modulation signals that are sent through a controller. The width of the electrical pulse determines the final position of the shaft which places the mechanism at the desired position.
You can control servo motors through manually controlled input devices like remote controls, joysticks, or servo switches. These input devices allow the user to manually control the position of the shaft by controlling the width of the pulse signal by hand. This type of controller is more often used in applications that do not require a quick succession of movements from the mechanism.
Servo motors can also be controlled by microcontrollers like Arduino boards or Rasberry Pi boards. These microcontrollers can be programmed to send the necessary PWM signals to position the shaft where desired. Microcontrollers can be set up to control multiple movements in succession by varying the width of the electrical pulse provided by the motor driver.
Most industrial and manufacturing applications use a dedicated Servo controller. These controllers are much more complex and have the ability to synchronize many servo motors to complete a series of functions. Servo controllers are programmed with thousands of signals that move one or multiple servo motor shafts into the positions needed to complete the desired task.
How to Program a Servo Motor?
Servo motors can be programmed in a variety of different ways depending on the complexity of the application and the number of servo motors used within a mechanism. Here are a few ways to automate the movements of a servo motor.
Microcontrollers
Microcontrollers are small programmable boards that can control anywhere from 1 to 48 servos depending on the size of your board. Microcontrollers like the Arduino board use premade commands from their servo library to program the movement of the shaft. Once your microcontroller is connected to your servo motor, you can connect it to your PC to enter a list of commands.
The microcontroller processes these commands and sends the necessary signals to move your servos to their intended positions when required. You may need to adjust input values to make your commands compatible with your specific servo motor.
Programmable Logic Controller and Servo Drives
While microcontrollers are great for small applications, industrial applications require a much more complex set of commands to run a high volume of servo motors efficiently.
Many industrial applications of servo motors use a programmable logic controller and servo drive to input complex commands. Start by connecting your PLC to your servo drive and configure your drive to your PLC. Simtach servo drives are widely compatible making it easy to get started. Once the drive and place are configured, you can begin programming your servo motors through your PLC.
The PLC can be programmed with a graphical interface to set the specific positioning, speed, and torque required for the application. This can be programmed into the servo drive which will then run the commands autonomously.
Many complex industrial setups use specialized motion control software that allows for maximum efficiency in advanced features like the synchronization of many servo motors as well as real-time adjustments. This software is usually preprogrammed and applied within the PLC.
Does a Servo Motor need a Motor Driver?
No, servo motors do not require a motor driver to function. However, a motor driver makes servo motors automated which allows for a more efficient use of multiple servo motors. If you are looking to automate your servo motors to perform a task or your servo motors are used as part of an automated manufacturing component, you will need a motor driver.
Motor drivers act like the brains of your servo motors. The motor driver provides the servo motor with power and controls the rotational direction and position of the servo motor by translating the input commands into the necessary PWM signals.
Motor drivers control the servo motors’ speed, rotation, and torque and are a key component in servo motors for both safety and functionality. Without a compatible motor drive, it is impossible to automate your servo motors. An easily configurable motor drive can vastly improve the efficiency and potential applications of your servo motors.
How to Program a Servo Motor?
Servo motors can be programmed in a variety of different ways depending on the complexity of the application and the number of servo motors used within a mechanism. Here are a few ways to automate the movements of a servo motor.
Microcontrollers
Microcontrollers are small programmable boards that can control anywhere from 1 to 48 servos depending on the size of your board. Microcontrollers like the Arduino board use premade commands from their servo library to program the movement of the shaft. Once your microcontroller is connected to your servo motor, you can connect it to your PC to enter a list of commands.
The microcontroller processes these commands and sends the necessary signals to move your servos to their intended positions when required. You may need to adjust input values to make your commands compatible with your specific servo motor.
Programmable Logic Controller and Servo Drives
While microcontrollers are great for small applications, industrial applications require a much more complex set of commands to run a high volume of servo motors efficiently.
Many industrial applications of servo motors use a programmable logic controller and servo drive to input complex commands. Start by connecting your PLC to your servo drive and configure your drive to your PLC. Simtach servo drives are widely compatible making it easy to get started. Once the drive and place are configured, you can begin programming your servo motors through your PLC.
The PLC can be programmed with a graphical interface to set the specific positioning, speed, and torque required for the application. This can be programmed into the servo drive which will then run the commands autonomously.
Many complex industrial setups use specialized motion control software that allows for maximum efficiency in advanced features like the synchronization of many servo motors as well as real-time adjustments. This software is usually preprogrammed and applied within the PLC.
Does a Servo Motor need a Motor Driver?
No, servo motors do not require a motor driver to function. However, a motor driver makes servo motors automated which allows for a more efficient use of multiple servo motors. If you are looking to automate your servo motors to perform a task or your servo motors are used as part of an automated manufacturing component, you will need a motor driver.
Motor drivers act like the brains of your servo motors. The motor driver provides the servo motor with power and controls the rotational direction and position of the servo motor by translating the input commands into the necessary PWM signals.
Motor drivers control the servo motors’ speed, rotation, and torque and are a key component in servo motors for both safety and functionality. Without a compatible motor drive, it is impossible to automate your servo motors. An easily configurable motor drive can vastly improve the efficiency and potential applications of your servo motors.
Where to Buy Servo Motors?
While there are many manufacturers of servo motors, Simtach Motors is an industry leader when it comes to reliable servo motors that are perfect for any application. Offering both AC and DC options, Simtach has a servo motor that is right for you.
Simtach also features AC and DC motor drives to help automate your servo motor applications and improve the accuracy of your servo motor.
Improve the efficiency and reliability of your automation with high-quality and affordable solutions from Simtach.
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