Stepper motor and driver correct selection method - Database & Sql Blog Articles

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Since there are many models and types of stepping motors and drivers, users should pay attention to them when choosing, so that they can choose the products they need with the best performance and lowest price.

1. First determine the torque required by the stepper motor to drag the load.

The easiest way is to add a lever to the load shaft and pull the lever with a spring balance. The tension multiplied by the arm length is both the load moment. Or theoretically calculated based on load characteristics.

Since the stepping motor is a control type motor, the maximum torque of the conventional stepping motor is not more than 45Nm. The larger the torque, the higher the cost. If the motor torque you choose is larger or exceeds this range, you can consider adding a reduction gear.

2. Determine the maximum operating speed of the stepper motor.

The speed index is very important in the selection of stepping motor. The characteristic of stepping motor is that as the motor speed increases, the torque decreases. The speed of the step is related to many parameters, such as the driving voltage of the driver and the phase current of the motor. The phase inductance of the motor, the size of the motor, etc., the general rule is: the higher the driving voltage, the slower the torque drop; the larger the phase current of the motor, the slower the torque drop. In the design scheme, the motor speed should be controlled within 600 rpm or 800 rpm, which is of course not standardized. Refer to <Motor-Frequency Characteristics>.

3. According to the two important indicators of load maximum torque and maximum speed, and then refer to <money-frequency characteristics>, you can choose the stepper motor that suits you.

If you think that the motor you selected is too large, you can consider adding a speed reducer, which can save costs and make your design more flexible. To choose the right reduction ratio, we must consider the relationship between torque and speed and choose the best solution.

4. Finally, consider leaving a certain (such as 50%) torque margin and speed margin.

5. You can choose a hybrid stepper motor first. If you have a price factor, you can choose a reactive stepper motor.

6. Try to subdivide the drive and make the drive work in a subdivided state.

7. When selecting and not going into the misunderstanding of only one indicator of motor torque, that is to say, the greater the torque of the motor, the better, and should be considered together with the speed index.

8. Ultra-small drives and micro-drivers are based on the outer casing as a heat sink. They should be fixed on a large, thick metal plate or external fan. If there is no heat dissipation, the drive works at a lower speed. When the drive heats up a lot, you can use a 90-type drive with a fan instead.