Stepper motors are the unsung heroes of the mechanical world, providing precise movement and positioning in a wide range of applications. But did you know that the origins of stepper motors can be traced back to the 19th century, when they were used in player pianos to create automatic music? That's right - stepper motors have been making music for over a century!
Today, stepper motors are used in everything from 3D printers to robotic arms, providing accurate and repeatable movement that is essential for these complex machines. But what exactly is a stepper motor, and how does it work? In this blog post, we'll dive into the world of stepper motors, exploring their different types, applications, advantages, and limitations. Whether you're a hobbyist or a professional engineer, there's a lot to discover about these fascinating devices. Let's get started!
What is a Stepper Motor?
A stepper motor is a type of electromechanical device that converts electrical pulses into precise mechanical movements. Unlike other types of motors, which rotate continuously, stepper motors move in small steps or increments, which makes them ideal for applications that require accurate positioning or speed control. Stepper motors typically consist of a rotor and a stator, with the rotor containing permanent magnets and the stator containing coils of wire. By energizing the coils in a specific sequence, the magnetic field of the rotor can be rotated in small increments, resulting in precise movement. Stepper motors come in various types, including bipolar and unipolar, and can be found in a wide range of applications, from 3D printers and CNC machines to medical equipment and robotics. However, that’s not all we’re gonna be talking about! Let’s dive in more!
Fig 1. Stepper motor in the robot
The Structure of the Stepper Motor
Stepper motors have 2 main parts.
- rotor
- Stator
- Winding
Rotor
The rotor in a stepper motor is the moving part of the motor that contains permanent magnets. The rotor typically has a shaft that extends from one or both ends, which can be used to connect the motor to other mechanical components in a system. When electrical current is applied to the coils in the stator of the stepper motor, the magnetic field of the rotor is pulled in a specific direction, causing the rotor to rotate in small increments. The position of the rotor is determined by the sequence and timing of the electrical pulses applied to the coils, making stepper motors well-suited for applications that require precise control over movement and positioning.
Stator
The stator in a stepper motor is the stationary part of the motor that surrounds the rotor. The stator typically contains coils of wire that are arranged in a specific pattern and are connected to an electrical driver. When an electrical pulse is applied to one or more of the coils in a specific sequence, a magnetic field is generated, which interacts with the permanent magnets in the rotor to produce rotational motion. The stator is responsible for controlling the movement of the rotor by generating the necessary magnetic fields, making it a critical component of the stepper motor. The design and construction of the stator can vary depending on the specific type of stepper motor, and different stator configurations can have an impact on the performance and characteristics of the motor.
Winding
Winding in a stepper motor refers to the coils of wire that are wrapped around the stator poles of the motor. Stepper motors typically have two or more windings, and each winding is made up of a certain number of turns of wire.
The windings in a stepper motor are responsible for producing the electromagnetic fields that interact with the permanent magnets on the rotor, causing the rotor to rotate in a precise manner. When electrical current is applied to the windings, they produce a magnetic field that interacts with the rotor, causing it to move a certain amount or "step" in response to each electrical pulse.
The number of windings and turns in each winding can affect the performance of the stepper motor, including its torque, speed, and resolution. Stepper motors with more windings and turns tend to have higher torque and better resolution, but they may also require more complex driver circuits and consume more power.
Fig 2. Motor structural diagram
Stepper Motor Winding Types
Winding in a stepper motor refers to the coils of wire that are wrapped around the stator poles of the motor. Stepper motors typically have two or more windings, and each winding is made up of a certain number of turns of wire.
The windings in a stepper motor are responsible for producing the electromagnetic fields that interact with the permanent magnets on the rotor, causing the rotor to rotate in a precise manner. When electrical current is applied to the windings, they produce a magnetic field that interacts with the rotor, causing it to move a certain amount or "step" in response to each electrical pulse.
The number of windings and turns in each winding can affect the performance of the stepper motor, including its torque, speed, and resolution. Stepper motors with more windings and turns tend to have higher torque and better resolution, but they may also require more complex driver circuits and consume more power.
- Unipolar winding: In an unipolar winding, each phase of the winding has a center tap that is connected to a positive voltage supply. The other end of each phase is connected to a switching transistor. By selectively turning on and off the transistors, the current flows through the appropriate phase of the winding, creating a magnetic field that causes the rotor to move. Unipolar windings are simple to control and require less complex driver circuits, but they tend to have lower torque and efficiency.
- Bipolar winding: In a bipolar winding, each phase of the winding has two ends that are connected to the switching transistors. By selectively reversing the direction of the current flow in each phase, the magnetic field is created that causes the rotor to move. Bipolar windings tend to have higher torque and efficiency than unipolar windings, but they require more complex driver circuits.
Fig 3. wiring
Stepper Motor Attributes
Stepper Motor Step
Step means the smallest controllable rotation in the stepper motor. Stepper motors are made with different precision depending on the type of application. The pitch angle is the angle traveled per step.
Fig 4. Motor steps
The Relationship Between Engine Revolutions and Steps
To calculate the number of steps taken by the engine in one second, we must multiply the number of revolutions per minute by the number of steps in one complete revolution and divide the resulting number by 60.
Example:
For a stepper motor with a speed of 300 RPM or 300 revolutions per minute with several steps of 200, the number of steps in one second is as follows:
1000=60/(200*300)
In this way, you can understand the real accuracy of the motor step, while 1000 steps per second are passed, but the next second, you can turn the motor movement into a stationary state in a specific step.
Stepper Motor Performance
Inside the stator of the stepper motor, several electric magnets have a step, these magnets are activated and deactivated by the control system by sending pulses. In the center of the motor is the rotor. The iron cylindrical rotor has a magnetic property and there are steps on it. By sending the first pulse and activating the first electromagnet, the rotor starts to rotate so that the steps of the rotor are exactly in front of the active electromagnet. In this case, the rotor step has a small deviation from the rest of the stator steps. With the activation of the next electromagnet and the deactivation of the first magnet, the rotor steps are aligned with the steps of the next magnet. By continuing this process, the rotor rotates and we can set the shaft of the stepper motor at the desired angle.
For example:
A 1.8-degree stepper motor must travel 200 steps to make one complete revolution.
(360 = 200 * 1.8)
Fig 5. Stepper motor
And in this way, it can be said that the higher the number of steps, the higher the performance accuracy. Stepper motors have an open-loop control system, which means they don't need a feedback system. The way the open loop system works is as follows:
Fig 6. Open loop vs closed loop
Phase in the Stepper Motor
The poles in the stepper motor are the same as the poles of the magnet. There may be a different number of windings in stepper motors. But these coils are connected in the form of groups called phases. All the coils of one phase start working together. Stepper motors generally have 2 phases, but 3-phase and 5-phase stepper motors are also available. Sometimes a unipolar stepper motor is known as a 4-phase stepper motor, when in fact it has 2 phases.
Pitch angle = 360 ÷ (number of poles per phase * number of phases) = 360 ÷ total number of phases
Stepper Motor Accuracy
Stepper motor accuracy refers to the ability of the motor to move precisely and accurately to a desired position. The accuracy of a stepper motor is affected by several factors, including the motor's step angle, the driver's micro-stepping mode, the mechanical system's design, and the load on the motor.
The step angle of a stepper motor is the angular distance that the motor shaft rotates for each step pulse. The smaller the step angle, the more precise the motor's movement. The accuracy of the motor can be improved by using a motor with a smaller step angle.
The micro-stepping mode of the motor driver can also affect the accuracy of the motor. Microstepping is a technique that allows the motor to move in smaller increments than its step angle. By using micro-stepping, the motor can achieve smoother and more accurate movement. However, it is important to note that using higher micro-stepping levels can also reduce the motor's torque and speed.
The mechanical system's design can also affect the motor's accuracy. Any mechanical play or backlash in the system can cause the motor to overshoot or undershoot the target position. Therefore, it is important to ensure that the mechanical system is designed and built to minimize any play or backlash.
Lastly, the load on the motor can also affect its accuracy. The motor's accuracy decreases as the load on the motor increases. Therefore, it is important to choose a motor with sufficient torque for the application to ensure accurate and precise movement.
In summary, stepper motor accuracy can be improved by using a motor with a smaller step angle, using micro-stepping, minimizing mechanical play and backlash, and ensuring that the motor has sufficient torque for the application.
Types of Stepper Motor
There are several types of stepper motors, including:
1.Permanent Magnet Stepper Motor: This type of stepper motor has a rotor with permanent magnets and a stator with multiple coils. The magnetic field of the rotor interacts with the magnetic field of the stator coils, producing rotational movement in small increments or steps. Permanent Magnet Stepper Motors are the most common type of stepper motor and are known for their accuracy, precision, and ease of control. They are used in a variety of applications, including robotics, automation, and manufacturing.
2.Variable Reluctance Stepper Motor: This type of stepper motor has a rotor with soft iron teeth and a stator with multiple windings. As the rotor rotates, the teeth align with the stator windings, creating a magnetic field and producing motion. Variable Reluctance Stepper Motors are less expensive but less accurate than other types of stepper motors. They are commonly used in applications that require low cost and low precision, such as consumer electronics and automotive systems.
3.Hybrid Stepper Motor: Hybrid stepper motors combine the features of Permanent Magnet and Variable Reluctance Stepper Motors. They have a rotor with permanent magnets and a stator with multiple teeth and coils. The teeth of the rotor align with the stator teeth, creating a magnetic field and producing rotational movement in small increments or steps. Hybrid stepper motors offer high accuracy, speed, and torque, making them ideal for applications that require precise positioning and control.
4.Linear Stepper Motor: Linear stepper motors produce linear motion instead of rotational motion. They consist of a moving part (usually a magnetic platen) and a stationary part (usually a coil assembly). As electrical current is applied to the coils, the magnetic field interacts with the magnetic platen, producing linear motion. Linear stepper motors are used in a variety of applications, including precision positioning systems, semiconductor manufacturing equipment, and medical devices.
Stepper motors can also be classified based on their wiring configurations, including bipolar and unipolar stepper motors. Bipolar stepper motors have two coils per phase and require an H-bridge driver circuit, while unipolar stepper motors have multiple coils per phase and can be driven with a simple transistor circuit.
Stepper Motor Types Based on Features
Stepper motors can also be classified based on the additional components or features that are integrated with them. Two examples of such classifications are:
Stepper Motor With Brake
The Stepper motor is sometimes used to carry and move weight or load on the vertical axis, when the electric current is not connected to the stepper motor, we may need a brake to keep the stepper motor in a fixed place. For this case, a stepper motor with a brake is recommended. The braked stepper motor creates the capability that when the electric current is not connected to the stepper motor, no movement is made, and the so-called stepper motor is in a locked state.
Step Motor With Gearbox
A stepper motor with a gearbox has an additional gear system that is integrated with the motor. The gearbox allows the motor to produce higher torque or slower speed output than it would normally be able to achieve. Stepper motors with gearboxes are commonly used in applications that require high torque or low speed, such as in conveyor systems or heavy machinery.
Stepper Motor With Encoder
A stepper motor with an encoder has an additional sensor that is integrated with the motor to provide feedback on the motor's position or speed. The encoder allows for more precise control of the motor, which is especially useful in closed-loop control systems. Stepper motors with encoders are commonly used in applications such as robotics, automation, and CNC machines.
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Stepper Motor With Integrated Driver
A stepper motor with an integrated driver has the driver circuitry integrated into the motor itself. This can simplify the wiring and control of the motor, as the driver and motor are combined into a single unit. Stepper motors with integrated drivers are commonly used in applications where space is limited or where multiple motors need to be controlled independently.
Fig 7. Stepper motors
Types of Stepper Motors Based on the Shaft
Stepper motors have different shafts, and according to the type of application, we must choose the stepper motor with the right shafts. There are three types of shafts in stepper motors below.
1.Round Shaft Stepper Motor: A round shaft stepper motor has a cylindrical shaft that is typically smooth and without any flats or keyways. This type of stepper motor is commonly used in applications where the motor is directly coupled to the load or where a shaft coupling can be used.
2.D-Shaft Stepper Motor: A D-shaft stepper motor has a shaft that is shaped like the letter "D". This type of stepper motor is commonly used in applications where a shaft coupling or gear is needed, as the flat surface of the D-shaft provides a secure connection.
Fig 8. D-shaft
3.Flatted Shaft Stepper Motor: A flatted shaft stepper motor has a round shaft that has been flattened on one or more sides. This type of stepper motor is commonly used in applications where a shaft coupling or gear is needed, as the flat surface provides a secure connection.
4.Splined Shaft Stepper Motor: A splined shaft stepper motor has a shaft that is shaped like a gear or a series of teeth. This type of stepper motor is commonly used in applications where precise angular positioning is required, such as in rotary indexing tables or other similar mechanisms.
5.Threaded Shaft Stepper Motor: A threaded shaft stepper motor has a shaft that is threaded like a screw. This type of stepper motor is commonly used in applications where precise linear motion is required, such as in lead screw assemblies or linear actuators.
Wiring in the Stepper Motor
A 2-pole, 2-phase stepper motor has 2 groups of windings, a 2-pole 2-phase stepper motor has 4 wires, and each group of windings has 2 wires. A single pole 4-phase motor has 4 windings. Some stepper motors have flexible wiring, which allows us to run the stepper motor both unipolarity and bipolarly.
Stepper motors have different wiring according to whether they are unipolar or 2-polar and the application we expect from them.
5 wires: This style of wiring is common in small unipolar stepper motors. The common wires are joined together and a common fifth wire is formed. This type of stepper motor can only be started in a unipolar way.
6 wires: In such stepper motors, each phase has 3 wires, you can connect the middle 2 wires and use it as a single-pole stepper motor, or do not connect it and use it as a 2-pole stepper motor.
8 wires: The most versatile stepper motors are 8 wires, these stepper motors can be started in different ways.
4 single-pole phases: like a 5-wire stepper motor, all common wires can be combined.
2-phase 2-pole series: the phases are connected in series, like a 6-wire stepper motor.
2 phases of 2 parallel poles: the phases are connected in parallel. The result is less resistance in the circuit but requires twice as much current to enter. The result of this wiring is higher torque and final speed.
Fig 9. Stepper motor wiring
What is the Maximum Speed of a Stepper Motor?
The maximum speed of a stepper motor depends on several factors, including the motor's design, the number of steps per revolution, the step angle, and the drive voltage. In general, stepper motors can achieve speeds up to several hundred revolutions per second (RPS), with some high-performance motors capable of speeds up to 1,000 RPS or more. However, the actual achievable speed in a particular application will depend on factors such as the load, the mechanical system's design, and the driver's ability to supply sufficient current to the motor coils.
The Useful Life of the Stepper Motor
Due to the structural system of the stepper motor, which is a brushless DC motor, the stepper motors have a long life. A typical stepper motor can operate for about 10,000 hours under normal use. If we use the stepper motor for an 8-hour shift every day, this part will have a life of about 4 years and 10 months.
Applications of Stepper Motor
Stepper motors have a wide range of applications in various industries due to their precision, accuracy, and ease of control. Some common applications of stepper motors include:
- Robotics and Automation
Stepper motors are widely used in robotics and automation systems for precise positioning and control. They are commonly used in robotic arms, CNC machines, 3D printers, and other industrial machinery.
- Printing and Imaging
Stepper motors are often used in printers, scanners, and other imaging equipment to precisely control the movement of print heads, paper feed mechanisms, and other components. They are also used in camera lenses for autofocus and zooming.
- Medical Equipment
Stepper motors are used in medical equipment such as MRI machines, infusion pumps, and respirators for precise and accurate control of movement and dosage. They are also used in laboratory equipment such as centrifuges and microscopes.
- Textile Machinery
Stepper motors are used in textile machinery for precise control of the fabric feed mechanism, allowing for accurate and consistent production of fabrics.
- Consumer Electronics
Stepper motors are used in a variety of consumer electronics, including disk drives, gaming consoles, and camera lenses. They are also used in home appliances such as washing machines and dishwashers for precise control of the motor speed and movement.
Overall, stepper motors play a critical role in many different industries and applications, providing precise and accurate control for a wide range of machinery and equipment.
Fig 10. Industrial stepper motor
Let's take a peek into the future of robots:What would be the future scope of robotic process automation?
Setting Up a Stepper Motor and the Concept of Micro-Stepping
Since stepper motors are designed and built to achieve precise movements under fully controlled conditions, they need a control system for this purpose and to send a set of motion commands. This control set includes two main parts of the controller (processor, CPU) and the driver. There are different types of industrial controllers, among which PLCs, Mach3 boards, Arduino, Raspberry Pi, etc. can be mentioned. Based on their inherent parameters and structures, these controllers transmit motion signals such as speed, angle, acceleration, direction, etc. to the motor driver based on the reference codes, and the step motor driver amplifies these signals and sends commands. Motors based on voltage and current drive the stepper motor with the required motion conditions.
Motion programming of stepper motors happens through controller software, and the driver has no special ability in this field, and this part is responsible for only amplifying the signal and sending the voltage and current required for any type of movement to the motor. As there are different types of controllers, the stepper motor driver also has different types such as face board, industrial drivers, and micro-stepping. Consumers of these parts choose different models of motors, drivers, and controllers according to their designs and needs and set up their systems. As you know, stepper motors have an inherent step angle. For example 1.8 degrees. If the motion accuracy is more than this value, it is necessary to use the driver's micro stepping function, which is in the form of dip switches on the driver (how to set it in the datasheets of each driver) and by using the controller, motion commands transferred to it. Some stepper motor drivers can divide each motor step into 1024 parts. But controlling this issue is not an easy task, and it may cause a lot of movement accuracy or damage to the engine. For this purpose, all three parts of this system, i.e. motor, driver, and controller, must have the ability and readiness for this behavior.
Fig 11. Setting up stepper motor
Safety When Installing the Stepper Motor
As mentioned, the main advantage of the stepper motor is high accuracy and the ability to control speed and movement. Therefore, any impact may cause damage to the motor. When installing the stepper motor, one should be careful of the impacts that may be inflicted on the shaft, these impacts may cause side effects such as engine failure, and motor locking, excessive shaking of the engine and not working accurately.
Choosing the Right Stepper Motor
Dimensions of the Stepper Motor
One of the most important decision-making factors is your expectation and the task that the stepper motor must perform. As expected, larger engines are capable of producing more power. Stepper motors have a large dimensional range. For example, it is common to use screen size 17 in 3D printers. Smaller motors are used in robots. Motors with larger sizes are used in numerical control machines (CNC) and industries. But it should be noted that 2 engines of the same size may have completely different specifications in practice.
Torque
Perhaps the most important point that a step motor buyer pays attention to is the motor torque. The motor torque indicates the power of the stepper motor. The unit of measuring torque is the Newton meter, which is displayed as Nm. Another torque measurement unit that is common in choosing a stepper motor is kg-cm. The torque of the stepper motor should match your application.
How Can I Measure the Stepper motor Torque?
To measure the torque of a stepper motor, you can use a torque sensor or a torque meter. These devices can be connected to the motor shaft to measure the amount of force or torque that is being produced as the motor rotates. Alternatively, you can calculate the torque based on the motor's specifications, such as the current and voltage ratings, the number of windings, and the motor's physical dimensions. However, it is important to note that the calculated torque may not be as accurate as the measured torque, as it does not take into account external factors such as friction and load.
Current Consumption
To produce torque in the stepper motor, the coils must receive electric current, so the current received is directly related to the torque. The current consumed by the stepper motor will be directly related to the type of operation and torque of the stepper motor and will be one of the important factors in determining the power of the stepper motor.
The Number of Phases
Stepper motors are available in single-phase, 2-phase, 3-phase, 4-phase, and 5-phase models. Generally, more phases will increase the power of the stepper motor.
The number of wires: Stepper motors have different numbers of wires depending on the number of phases they have and whether they are single-pole or double-pole. Step motors have 4, 5, 6, and 8-wire models. This variety in the number of wires will give the buyer great maneuverability to choose.
Stepper Motor Brand
Different brands produce stepper motors. Some of them may have a higher price, but they will also have better quality. Leadshine, Primopal, Moons, CW, and HQM brands can be mentioned as good brands that produce step motors.
Fig 12. Stepper motor dimension
Difference Between the Stepper Motor and Servo Motor
Despite the many similarities, stepper motors, and servo motors also have significant differences, which we will discuss further.
- A servo motor has a more complex structure than a stepper motor.
- With the feedback system, servo motors can control the position moment by moment.
- Servo motors have a higher rotation speed.
- Servo motors have a higher torque output.
- Due to the advanced control system, servo motors have less vibration.
- The price of servo motors is significantly higher than step motors.
- The number of magnetic poles in the stepper motor is between 50 and 400. This number is between 4 and 12 in the servo motor.
- The efficiency of the stepper motor is higher in the long run.
- The Servo motor has less noise than the stepper motor.
- Note: With the encoder, you can use a step motor instead of a servo motor. This system will add some servo motor control power to stepper motors.
Important Points for Choosing Between the Servo Motor and Stepper Motor
If you are hesitant to choose between a stepper motor and a servo motor, consider the following points for your application and make the best choice.
- Required torque
- required speed
- required acceleration
- Consumption flow
- the budget
- Space limitation
Fig 13. Servo vs stepper motor
Stepper Motor Calibration
Stepper motor calibration is the process of determining the motor's characteristics, such as step angle, holding torque, current rating, and configuring the control system to ensure accurate and precise movement. Here are the steps to calibrate a stepper motor:
- Determine the motor's step angle: The step angle is the angle through which the motor rotates for each electrical pulse received by the motor driver. You can measure the step angle by rotating the motor shaft by hand and counting the number of steps per revolution.
- Measure the holding torque: The holding torque is the amount of torque required to prevent the motor from rotating when it is powered but not moving. You can measure the holding torque using a torque sensor or by applying a load to the motor shaft and measuring the force required to keep the motor stationary.
- Set the current limit: The motor's current limit is the maximum amount of current that can be supplied to the motor coils without causing overheating or damage. You can set the current limit using the motor driver's current control feature.
- Set the micro-stepping mode: Microstepping is a technique that allows the motor to move in smaller increments than its step angle. You can set the micro-stepping mode using the motor driver's configuration settings.
- Test the motor movement: After calibrating the motor, you should test its movement by sending a series of commands to the motor driver and observing the motor's response. You may need to adjust the current limit or micro-stepping settings to achieve the desired level of precision and accuracy.
Overall, stepper motor calibration is an important process that can ensure accurate and reliable movement in a wide range of applications, including CNC machines, 3D printers, and robotics.
Advantages of Stepper Motor
- Ability to control shaft rotation by input pulses
- The ability to keep the shaft steady
- Due to the step movement, they have good positionality.
- Excellent execution of stop, move and reverse commands
- Long service life due to the absence of a brush
- Open loop control
- Good torque production at low speed
- proper torque
- The price is reasonable
Disadvantages of Stepper Motor
- Requires high precision during adjustment
- If it is not adjusted properly, the engine performance will be problematic and may result in engine failure.
- Inability to access high-speed
Conclusion
According to the topics we discussed the stepper motor, we know that the stepper motor is a DC motor that divides a complete cycle into several steps. Therefore, it will be highly accurate. But to have higher accuracy, we can check the servo motor, servo motors will of course be expensive for us. According to the requirement, we have to choose the right stepper motor. These days, hybrid stepper motors are used. Hybrid stepper motors are divided into different categories such as brake, gearbox, waterproof, and encoder, each of which has its specific application. Finally, it should be said that the stepper motor is an integral part of the industry these days.
Future of Stepper Motors and Their Impact on Technology and Society
As technology continues to evolve, stepper motors are likely to play an increasingly important role in a wide range of applications. Some of the key trends and developments that are likely to shape the future of stepper motors include:
- Advances in Control and Driver Circuits
As more sophisticated control and driver circuits are developed, stepper motors will become more efficient, precise, and capable of operating at higher speeds. This will enable them to be used in a wider range of applications, from high-speed machining to precise robotic movements.
- Integration with Artificial Intelligence and Machine Learning
Stepper motors can be integrated with artificial intelligence and machine learning algorithms to improve their performance and make them more adaptable to changing conditions. This will enable stepper motors to be used in more complex and dynamic applications, such as autonomous vehicles and smart factories.
- Emergence of New Applications
As technology continues to evolve, new applications for stepper motors are likely to emerge. For example, they could be used in the emerging field of soft robotics, where flexible materials are used to create robots that can perform tasks that are difficult or impossible for rigid robots.
The impact of stepper motors on technology and society is likely to be significant in the coming years. Some of the potential benefits of stepper motors include:
- Increased Efficiency and Productivity
By enabling precise and accurate control of machinery and equipment, stepper motors can help to increase efficiency and productivity in a wide range of industries.
- Improved Safety and Reliability
Stepper motors can be used to improve safety and reliability in machinery and equipment, reducing the risk of accidents and downtime.
- Lower Environmental Impact
Stepper motors are typically more energy-efficient than other types of motors, which can help to reduce energy consumption and lower the environmental impact of industrial processes.
To recap:
1.What is a stepper motor?
A stepper motor is an electromechanical device that converts electrical pulses into precise mechanical movement. Unlike a DC motor, a stepper motor moves in steps or increments, allowing for precise control of position and speed.
2.How does a stepper motor work?
A stepper motor works by receiving electrical pulses from a controller, which causes the motor to rotate in small, precise steps. The number of steps per revolution and the direction of rotation depending on the motor's construction and the number of windings.
3.What are the advantages of using a stepper motor?
Stepper motors offer several advantages, including precise positioning, excellent speed control, and high torque at low speeds. They also have a simple construction and are relatively easy to control.
4.What are the different types of stepper motors?
The most common types of stepper motors are
- Permanent magnet stepper motors
- Variable reluctance stepper motors
- Hybrid stepper motors
5.How do you control a stepper motor?
To control a stepper motor, you need a stepper motor controller that can generate the appropriate electrical pulses to drive the motor. The controller can be connected to a microcontroller, computer, or other control systems.
6.What is the maximum speed of a stepper motor?
The maximum speed of a stepper motor depends on the motor's construction, the number of windings, and the power supply voltage. Generally, stepper motors can achieve speeds up to a few hundred revolutions per second.
7.What is the holding torque of a stepper motor?
The holding torque of a stepper motor is the amount of torque required to prevent the motor from turning when it is powered but not rotating. It depends on the motor's construction, the number of windings, and the current supplied to the motor.
8.Can a stepper motor run continuously?
Yes, a stepper motor can run continuously, but it is not recommended. Continuous operation can cause the motor to overheat and reduce its lifespan.
9.What are the applications of stepper motors?
Stepper motors are used in a wide range of applications, including robotics, CNC machines, 3D printers, camera autofocus systems, medical equipment, and more.
10.How do you select the right stepper motor for your application?
To select the right stepper motor for your application, you need to consider factors such as the required torque, speed, and accuracy, as well as the operating voltage and environment. It is also important to choose a motor that is compatible with your control system and power supply.
17th Apr 2023
FAQs
How can I increase the power of my stepper motor? ›
However, if the primary space limitation is motor diameter, engineers can increase step-motor torque within a given frame size by increasing the motor's length. To build a step motor with higher torque, several rotor and stator sections are “stacked” together, thus the increased length.
What is the revolution of stepper motor? ›Standard hybrid stepping motors have 200 rotor teeth, or 200 full steps per revolution of the motor shaft. Dividing the 200 steps into the 360° of rotation equals a 1.8° full step angle. Normally, full step mode is achieved by energizing both windings while reversing the current alternately.
How can we control the speed of the stepper motor? ›Useful for Speed Control and Position Control
The rotating speed of the stepper motor is determined by the speed of the pulse frequency (Hz) given to the driver, and it is possible to freely change the motor rotation by simply changing the number of input pulses or frequencies to the driver.
Stepper motor control provides this input train of pulses to command the motor to move to the desired position or at the desired speed. Stepper motor control constant voltage drives are used to apply a constant positive or negative voltage to each winding to drive motion.
How do you increase stepper motor precision? ›Another mechanical adjustment to gain accuracy in your stepper motor is to use a smaller inertia load. If the motor is attached to a large inertia when it tries to stop, the load will cause some slight over-rotation. Because this is often a small error, the motor controller can be used to correct it.
How do you control the torque of a stepper motor? ›Torque in a motor depends on current going through the motor's coils. Therefore, the common and logical way to control this torque is to perform a current regulation by monitoring it directly. This method is called the current mode control. Another way to drive a motor, called voltage mode control, exists.
How speed of stepper motor is increased? ›There are two ways you can control the speed of your stepper motor. You can either decrease the delay time between each step or you can adjust the size of the step the motor takes. Decreasing the delay time is straightforward, just lower the delayMicroseconds and the stepper motor will have an increased step rate.
How do you set steps per revolution in a stepper motor? ›Stepper motors have a step angle. A full 360° circle divided by the step angle gives the number of steps per revolution. For example, 1.8° per full step is a common step size rating, equivalent to 200 steps per revolution.
What is the maximum revolution of stepper motor? ›If you want to know about stepper motor max speed, you should know that the maximum speed that's typical of a stepper motor is 1000rpms while the max speed of gearmotors comes in at 400-550 RPM.
How can a stepper motor be controlled without a microcontroller? ›- Step 1: Get All the Stuff.
- Step 2: Start by Plugging on the A4988 Motor Driver on the Breadboard.
- Step 3: Get Help From the Circuit Schematic.
- Step 4: Wire Up and Test the Speed Controller.
- Step 5: Wire Up and Test the Direction Controller.
- Step 6: It's DONE.
How do you control a stepper motor like a servo? ›
No, a stepper can't be used like a servo, because the output shaft has no memory of the starting position. You need to "home" the stepper during startup, either by using a limit switch or running into an end stop, or use a shaft encoder to define absolute orientation.
What voltage does a stepper motor control? ›Generally, 12 [V] is the smallest voltage used to drive actuator motors, with higher voltages at 24 [V], 48 [V] and even 80[V] being used for motion control systems. A good rule of thumb is to use between 10 and 24 times the motor's nameplate voltage for the system bus voltage.
How to control speed of stepper motor by potentiometer? ›Use the analog input with the help potentiometer to control the delay in-between each steps of the stepper motor. Shorter the delay in-between each steps - faster the stepper motor runs and vice-versa.
How to control stepper motor using PWM? ›Step 3: PWM for Stepper Motors
Each pulse on the step line causes the motor to move a step, or part step, in a give direction. For stepper motor driver control the duty cycle can be fixed and the Frequency varied. The stepper motor driver expects a series of input pulses to move the motor to any given angle.
When selecting a stepper motor for your application, there are several factors that need to be taken into consideration: How will the motor be coupled to the load? How fast does the load need to move or accelerate? How much torque is required to move the load?
How do you vary the speed and direction of a stepper motor? ›Reversing the direction of the current in the coils produces motion in the same direction. To change direction you need to reverse the current in one set of coils only. At the moment the two motors are connected in parallel and turn in the same direction.
How do I increase my stepper driver current? ›Turning the potentiometer clockwise increases the current to the stepper motor. A higher motor current results in more torque but also more heat. Be careful not to set currents higher than the maximum current that the motor can accept.
How do you increase stepper motor torque with gears? ›Adding a gearbox to a stepper motor system can improve the motor's performance by decreasing the load-to-motor inertia ratio, increasing torque to the load, and reducing motor oscillations.
What does stepper motor depend on? ›The speed of a stepper motor depends on the rate at which you turn on and off the coils, and is termed the 'step-rate'. The maximum step-rate, and hence, the maximum speed, depends upon the inductance of the stator coils.
What is the relationship between torque speed and stepper motor? ›The typical design of a stepper motor means that torque delivery is directly proportional to the current passing through the motor windings: the higher the current, the higher the torque delivered by the motor.
How do you convert steps per revolution to RPM? ›
If N is the speed in revolution per minute (rpm), S is the steps per second (sps), then step per revolution (spr) is given as, sps=N×S60=rpm×spr60. Q. A record player makes 60 rpm (revolution per minute).
How do you calculate rpm of a stepper motor? ›RPM = (steps per second) x (revolutions per step) x (60 seconds per minute).
What is holding torque in stepper motor? ›If external force is applied to a stepping motor when it is stopped but energized, the attractive force generated between the rotor and stator works to maintain the stop position of the motor. This torque of withstanding the external force is called the holding torque.
What happens if you overload a stepper motor? ›When a stepper motor gets overloaded, mechanicly, is stops, it "stalls" and the rest of the movement is lost. Normal design is to use steppers stronger than the maximum load.
Which torque is high in stepper motor? ›NEMA08 to 53. A series of step motors that have been designed by JVL for use with the entire range of JVL Step Motor Drivers and Controllers. They are high torque step motors especially made for mini- and microstep operation.
Can you make a stepper motor run continuously? ›Stepper motors can continue to rotate indefinitely, just as most motors will. If you use a properly designed controller and a stepper motor that's sized appropriately for the application, the motor can be left running.
How do you control the direction of a stepper motor? ›Commands to run and control stepper motor from Bluetooth
s or S = Starts and stops the stepper motor. First s starts motor and the coming next stops it. f or F = Rotates stepper motor in clockwise direction. b or B = Rotates stepper motor in anticlockwise direction.
Discrete outputs from a PLC can be used to drive a stepper motor controller, and even some servo motor controllers, if desired. Two outputs are needed for each controller; one for the pulse frequency, and the other for direction.
Can I control a DC motor with stepper driver? ›This DC motor can be controlled by the signal's direction as well as step like a normal stepper motor with driver, only that my solution already brings the driver.”
Which is better servo or stepper motors? ›Servo motors offers more efficient current control because it only draws the current it needs. One thing that a stepper motor is better at is its ability to generate holding torque at zero speed. Servo motors use more power to generate holding torque.
Is a continuous servo better than a stepper motor? ›
In general, servo motors are more sophisticated than stepper motors. They run significantly faster than stepper motors, with speeds on the order of several thousand RPMs (see figure 3). This enables servo motors to be used with gearboxes to deliver much higher torque at useful speeds.
How do you stop a stepper motor from vibrating? ›From a manufacturing standpoint, a stepper motor's tendency to vibrate can be reduced by changing the rotor inertia (through material or design changes) and by altering the size of the air gap between the motor and stator, which in turn, changes the motor's torque stiffness.
How do you control motor speed with frequency? ›A variable frequency drive controls the motor speed by using PWM (Pulse Width Modulation) to alter the power supply frequency that's fed to the motor. There is typically no feedback coming back from the motor; although some drives uses back EMF as feedback.
How do you increase torque and reduce speed? ›This is done by changing the electromagnetic characteristics of the motor by altering either the wire size or the number of wire turns in the winding, or both. More turns of smaller wire provides more torque and less speed where fewer turns of larger wire provides higher speed but less torque.
Can you control torque with electric motor? ›Direct torque control (DTC) is one method used in variable-frequency drives to control the torque (and thus finally the speed) of three-phase AC electric motors. This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.
Does a stepper motor generate AC or DC? ›A stepper motor, also known as step motor or stepping motor, is a brushless DC electric motor that divides a full rotation into a number of equal steps.
Can you overvolt a stepper motor? ›When is the application of overvoltage safe (and common) for stepper motors? For most types of motors, operating with a supply voltage that is higher than the rated voltage — referred to as overvoltage — can cause an increase in current, and heat, high enough to damage the coils and other motor components.
Is stepper motor AC or DC current? ›A stepper motor is driven by a DC voltage applied through a driver.
Can I use a potentiometer to control motor speed? ›A variable resistor is known as a rheostat, but potentiometers can be made to function as rheostats quite easily. In this project, you learn how to use a potentiometer to control the speed of a motor, as illustrated in Figure 1.
Which factor governs the speed of stepper motor? ›The quantity of pulses to the drive determines the amount of rotational or linear movement and the frequency of the pulse train determines the rotational or linear speed of the stepper motor or linear actuator, respectively.
Can Raspberry Pi control stepper motor? ›
Raspberry Pi's GPIOs can be used to control stepper motor rotation.
How to control speed of stepper motor using Arduino? ›The speed of the stepper motor will now be controlled by the potentiometer. The output from the potentiometer is read into analog port A0. In the next line, the integer stored in potReading should be within the range of (0-1023) determined by the voltage read at A0.
How to control the motor speed with PWM and how to generate it? ›If such a signal is fed to a DC motor, we can change the speed of the motor by changing the duty cycle of the PWM signal. The change in pulse width is created by increasing the on-time (HIGH value) of the pulse while reducing the off-time (LOW value) by the same amount so that the frequency of the signal is constant.
What is the best voltage for stepper motors? ›Generally, 12 [V] is the smallest voltage used to drive actuator motors, with higher voltages at 24 [V], 48 [V] and even 80[V] being used for motion control systems. A good rule of thumb is to use between 10 and 24 times the motor's nameplate voltage for the system bus voltage.
How much power is needed for a stepper motor? ›A switching regulator only draws from the power supply for brief amounts of time, so a stepper motor that draws 3A at 2 volts per coil, would draw 3A x 2V = 6 Watts per coil or 12 Watts. At 48 volts 12 Watts would only require .
What voltage should a stepper motor run? ›Stepper motors are very easy to control. Most drivers are looking for 5 volt pulses which just so happen to be the voltage level of most integrated circuits.
What happens if you give a stepper motor too much current? ›If the current is too high, you lose the linearity of micro-stepping. If the highest current exceeds the maximum, then the highest current micro-stepping positions will collapse on each other. If you are within the specs of the motors, there are no motor-related problems caused by higher currents.
Does voltage affect stepper motor torque? ›Another factor which limits the torque output of stepper motors at high speed is the rate of increase of current in the windings (dI/dt), which is directly proportional to the applied voltage (V) and inversely proportional to the motor inductance (L).
Can you run stepper motor at higher voltage? ›Stepper motors are not perfectly efficient so some of the electrical power turns into heat. Operating a stepper motor at higher voltage will increase the motor heating due to eddy current losses even if the maximum current is kept the same.
What is the maximum rpm of a 12v stepper motor? ›If you want to know about stepper motor max speed, you should know that the maximum speed that's typical of a stepper motor is 1000rpms while the max speed of gearmotors comes in at 400-550 RPM.
How long can a stepper motor run continuously? ›
The typical lifetime of a stepper motor is 10,000 operating hours. This approximates to 4.8 years given that the motor operates one eight-hour shift per day. Motor lifetime may vary in regards to user application and how rigorously the motor is run.
What voltage is a NEMA stepper motor? ›NEMA 17 stepper motors are those that have a 1.8 degree step angle (200 steps/revolution) with a 1.7 x 1.7 inch faceplate. NEMA 17 steppers typically have more torque than smaller variants, such as NEMA 14 and have a recommended driving voltage of 12-24V.
What happens when you underpower a stepper motor? ›Running a stepper motor at under its rated current will affect both its maximum speed and torque (both holding and dynamic), though depending on the driver type, it mostly effects the torque.
Do stepper motors need constant power? ›Stepper motors really require to be driven from a constant CURRENT source rather than constant voltage. Provided that the max output voltage from the supply can be tolerated by the bridge drivers!