Stepper motor no-load maximum speed problem - Database & Sql Blog Articles

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Stepper motors are widely used in precision control systems due to their ability to rotate in precise steps. However, the maximum no-load speed of a two-phase stepper motor is often cited as up to 2000 rpm. While this number may seem impressive, it's important to understand that it's more of a theoretical reference rather than a practical measure. In reality, the torque of a stepper motor drops significantly as speed increases, and at higher speeds, the available torque becomes almost negligible.

When operating without subdivision, the motor moves in full steps, with one complete rotation requiring 200 pulses. Many users encounter issues where the motor stalls when reaching its maximum speed, leading to confusion about whether the system is functioning correctly. This is a common problem and not necessarily an indicator of malfunction. The real challenge lies in understanding how speed and torque interact in a stepper motor setup.

At lower speeds, typically between 300 and 600 rpm, the motor performs much more reliably. This range is where the motor can deliver sufficient torque to drive loads, especially when combined with a mechanical减速 device. For most applications, the motor is designed to operate at tens of revolutions per minute, which ensures high efficiency, stable power supply, and reduced noise levels.

Vibration is another factor that affects performance. To minimize vibration, it’s recommended to increase the subdivision of the driver. Higher subdivision allows for smoother motion and better control, making the motor suitable for precision tasks.

The formula for calculating the maximum no-load speed is as follows:

No-load speed (rev/min) = (60 × Clock Frequency) / (200 × Number of Subdivisions)

For example, if the clock frequency is 150 kHz and the number of subdivisions (M) is 16:

Maximum no-load speed ≈ (60 × 150,000) / (200 × 16) = 2812.5 rpm

This calculation shows that increasing the subdivision can significantly improve the motor’s performance at higher speeds, although it won't compensate for the loss of torque. Understanding these relationships helps in selecting the right configuration for your application.