1. How to choose servo motor and stepper motor correctly?

It mainly depends on the specific application situation. In short, it is necessary to determine: the nature of the load (such as horizontal or vertical load, etc.), the requirements for torque, inertia, speed, accuracy, acceleration and deceleration, and the requirements for upper control (such as port interface and communication requirements). requirements), the main control mode is position, torque or speed mode. Whether the power supply is DC or AC power, or battery powered, voltage range. Based on this, determine the model of the motor and the associated drive or controller.

2. Choose a stepper motor or a servo motor system?

Each has its own characteristics, depending on the specific application.

3. How to use the stepper motor driver?

According to the current of the motor, use a driver that is greater than or equal to this current. If low vibration or high precision is required, a subdivision driver can be used. For high-torque motors, use high-voltage drives as much as possible to obtain good high-speed performance.

4. What is the difference between 2-phase and 5-phase stepper motors and how to choose?

The 2-phase motor has low cost, but the vibration is large at low speed, and the torque drops quickly at high speed. The 5-phase motor has less vibration and good high-speed performance. It is 30-50% faster than the 2-phase motor, and can replace the servo motor in some occasions.

5. When to choose DC servo system, what is the difference between it and AC servo?

DC servo motors are divided into brushed and brushless motors. The brushed motor has low cost, simple structure, large starting torque, wide speed regulation range, easy control, and requires maintenance, but it is easy to maintain (replacement of carbon brushes), generates electromagnetic interference, and has environmental requirements. Therefore, it can be used in cost-sensitive general industrial and civil applications.

The brushless motor is small in size, light in weight, large in output, fast in response, high in speed, small in inertia, smooth in rotation and stable in torque. The control is complex, and it is easy to realize intelligentization. Its electronic commutation mode is flexible, and it can be square wave commutation or sine wave commutation. The motor is maintenance-free, has high efficiency, low operating temperature, small electromagnetic radiation, long life, and can be used in various environments.

AC servo motors are also brushless motors, which are divided into synchronous and asynchronous motors. At present, synchronous motors are generally used in motion control. They have a large power range and can achieve great power. High inertia, low maximum rotational speed, and decreases rapidly with increasing power. Therefore, it is suitable for applications that operate smoothly at low speeds.

6. What should be paid attention to when using the motor?

Check the following before power-on operation:

1) Whether the power supply voltage is appropriate (overvoltage may cause damage to the drive module); the +/- polarities of the DC input must not be wrongly connected, and whether the motor model or current setting value on the drive controller is appropriate (do not too large);

2) The control signal line should be firmly connected, and it is better to consider the shielding problem in the industrial field (such as using twisted pair);

3) Don't connect all the wires that need to be connected at the beginning, only connect to the most basic system, and then connect gradually after running well.

4) Be sure to figure out the grounding method, or use floating.

5) Within half an hour of starting to run, closely observe the state of the motor, such as whether the movement is normal, the sound and temperature rise, and immediately stop and adjust if any problems are found.

7. When the stepper motor starts to run, it sometimes stops moving or moves back and forth in place, and sometimes loses steps during operation. What is the problem?

Generally, the following aspects should be considered for inspection:

1) Whether the motor torque is large enough to drive the load, so we generally recommend that users choose a motor with a torque that is 50%~100% larger than the actual need, because the stepper motor cannot be overloaded, even for an instant. Cause loss of step, stop or move irregularly in place in severe cases.

2) Whether the current of the input walking pulse from the upper controller is large enough (generally >10mA) to make the optocoupler turn on stably, and whether the input frequency is too high, so that it cannot be received, if the output circuit of the upper controller If it is a CMOS circuit, a CMOS input type driver should also be used.

3) Whether the starting frequency is too high, and whether the acceleration process is set on the starting program, it is best to start accelerating from the starting frequency specified by the motor to the set frequency, even if the acceleration time is very short, otherwise it may be unstable or even in an idle state .

4) When the motor is not fixed properly, this situation sometimes occurs, which is normal. Because, in fact, the strong resonance of the motor is caused at this time, which leads to the out-of-step state. The motor must be fixed.

5) For a 5-phase motor, if the phases are connected incorrectly, the motor will not work.

8. Would you like to control the servo motor directly through communication?

Yes, it is more convenient, but it is only a matter of speed, and it is used for applications that do not require very high response speed. If fast response to control parameters is required, it is best to use a servo motion control card, which generally has DSP and high-speed logic processing circuits to achieve high-speed and high-precision motion control. Such as S acceleration, multi-axis interpolation, etc.

9. Is it good to use switching power supply to power stepper and DC motor system?

It is generally best not to, especially for high-torque motors, unless a switching power supply with more than twice the required power is used. Because the motor is a large inductive load when it is working, it will form an instantaneous high voltage on the power supply end. The overload performance of the switching power supply is not good, it will protect the shutdown, and its precise voltage regulation performance is not required, which may sometimes cause damage to the switching power supply and the driver. A DC power source that can be transformed with a conventional toroidal or R-type transformer.

10. Would you like to control the stepper motor with a DC voltage of ±10V or 4~20mA?

Yes, but requires an additional conversion module.

11. There is a servo motor with encoder feedback, can it be controlled by a servo driver with only a tachometer port?

Yes, it needs to be equipped with an encoder to tachometer signal module.

12. Can the encoder part of the servo motor be disassembled?

It is forbidden to disassemble, because the quartz plate in the code disc is easily broken, and after entering the dust, the life and accuracy will not be guaranteed, and professional maintenance is required.

13. Can stepper and servo motors be disassembled for maintenance or modification?

No, it is better to let the manufacturer do it. After disassembly, it is difficult to install it back to its original state without professional equipment, and the gap between the rotor and stator of the motor cannot be guaranteed. The performance of the magnetic steel material is destroyed, even causing loss of magnetism, and the motor torque is greatly reduced.

14. Can the servo controller sense the change of external load?

If you encounter the set resistance, stop, return or keep a certain thrust to follow up.

15. Can domestic drivers or motors be used with foreign high-quality motors or drivers?

In principle, it is possible, but the technical parameters of the motor can be used before it can be used. Otherwise, the due effect will be greatly reduced, and even the long-term operation and lifespan will be affected. It is best to consult with the supplier before deciding.

16. Is it safe to use a DC power voltage greater than the rated voltage to drive the motor?

Normally this is not a problem as long as the motor is running within the set speed and current limits. Because the motor speed is proportional to the motor line voltage, selecting a certain supply voltage will not cause overspeed, but failures such as the drive may occur.

In addition, it must be ensured that the motor meets the minimum inductance requirements of the drive and that the current limit set is less than or equal to the rated current of the motor.

In fact, it's nice if you can make the motor run slower (below rated voltage) in your design.

Running at lower voltage (and therefore lower speed) results in less brush running bounce, less brush/commutator wear, lower current draw and longer motor life.

On the other hand, if the motor size and performance requirements require additional torque and speed, overdriving the motor is fine, but at the expense of product life.

17. How to choose the appropriate power supply for the application?

It is recommended to select a power supply voltage value that is 10%-50% higher than the maximum required voltage. This percentage varies with Kt, Ke, and voltage drop within the system. The current value of the driver should be sufficient to deliver the energy required by the application. Remember that the output voltage value of the driver is not the same as the supply voltage, so the output current of the driver is not the same as the input current. To determine the proper supply current, calculate all power requirements for this application and add another 5%. According to the formula I=P/V, the required current value can be obtained.

18. Which working mode can be selected for the servo drive?

The different modes are not all present in all models of drives.

19. How are drives and systems grounded?

a. If there is no isolation between the AC power supply and the DC bus of the drive (such as a transformer), do not connect the non-isolated port of the DC bus or the ground of the non-isolated signal to the ground, which may cause equipment damage and personal injury. Because the AC common voltage is not to the ground, there may be a high voltage between the DC bus ground and the ground.

b. In most servo systems, all common grounds and grounds are connected together at the signal end. The ground loops created by the various ways of connecting the earth are susceptible to noise and flow at different reference points.

c. In order to keep the command reference voltage constant, connect the signal ground of the driver to the signal ground of the controller. It will also be connected to the ground of the external power supply, which will affect the operation of the controller and driver (eg: 5V power supply of the encoder).

d. It is more difficult to ground the shielding layer, and there are several methods. The correct shield ground is at the reference potential point inside its circuit. This point depends on whether the noise source and receiver are grounded at the same time, or floating. Make sure that the shield is grounded at the same point so that ground current does not flow through the shield.

20. Why can't the reducer be exactly matched with the motor at the standard torque point?

Many reduction ratios far exceed the torque rating of the reducer if the maximum continuous torque produced by the motor through the reducer is taken into account.

If we were to design each reducer to match full torque, the reducer's internal gears would have too many combinations (larger volume and more material). This will make the price of the product high and violate the "high performance, small size" principle of the product.

21. How to choose to use planetary reducer or spur gear reducer?

Planetary reducers are generally used when high torque is required in a limited space, that is, small volume and large torque, and its reliability and life are better than spur gear reducers. Spur gear reducers are used for lower current consumption, low noise and high efficiency and low cost applications.

22. What is the duty cycle?

The duty cycle refers to the ratio of the working time/(working time + non-working time) of the motor in each working cycle. If the load factor is low, the motor is allowed to run at 3 times the continuous current for short periods of time, thus producing more power than when running continuously at the rated value.

23. Can the drive circuit of a standard rotary motor be used for a linear motor?

Generally it is possible. You can think of linear motors as rotary motors, such as linear stepper motors, brushed, brushless, and AC linear motors. Please consult the supplier for details.

24. Can the linear motor be installed vertically and move up and down?

Can. According to the user's requirements, we can install the balance device of the mover slider or install the guide rail brake for vertical installation.

25. Can multiple movers be installed on the same platform?

Can. As long as several movers do not interfere with each other.

26. Can the mover coils of multiple brushless motors be installed on the same magnetic track?

Can. As long as several movers do not interfere with each other.

27. What are the advantages of using a linear motor over a linear motor with a ball screw?

Since there is no mechanical connection between the stator and the mover, the problems of backlash, wear, and jamming are eliminated, and the movement is smoother. It highlights the characteristics of higher precision, high speed, high acceleration, fast response, smooth motion, high control precision, good reliability, compact size, low profile height, long life and maintenance-free.

28. How to choose electric cylinder, sliding table and precision platform products? How is the cost calculated?

The key to choosing actuator products depends on what kind of requirements you have for motion parameters. You can determine the specific motion parameters and other technical conditions according to the application you need. These parameters must meet your actual needs, both to meet the application requirements and Leave room and don't raise it too high, otherwise the cost may be several times that of a standard product. For example, if 0.1mm accuracy is enough, don't choose 0.01mm parameter. Others such as load capacity, speed, etc. are also the same.

Another selection suggestion for users is that if it is not necessary, the three main parameters of push-pull or load, speed and positioning accuracy should not be very high at the same time, because the actuator is a high-precision and high-tech mechatronics product , we need to consider and select the corresponding motor, drive controller and feedback device from the aspects of mechanical structure, electrical performance, material characteristics, material and processing methods when designing and manufacturing, as well as guide rails, screw rods, supports of different precision levels The seat and other mechanical systems can achieve the required overall motion parameters, which can be described as a product that drives the whole body. Of course, if you have high-demand product needs, we can still meet them, but the cost will increase accordingly.