Stepper motor and its selection
The base numbers of stepper motors mainly include 35, 39, 42, 57, 86, 110, etc.

Construction of stepper motor: composed of rotor (rotor core, permanent magnet, shaft, ball bearing), stator (winding, stator core), front and rear end caps, etc. The stator of the most typical two-phase hybrid stepper motor has 8 large teeth, 40 small teeth, and the rotor has 50 small teeth; The stator of a three-phase motor has 9 large teeth, 45 small teeth, and the rotor has 50 small teeth.

Main parameters of stepper motor:

Phase number: refers to the number of coil groups inside the motor. Currently, commonly used ones include two-phase, three-phase, and five phase stepper motors.

Beats: The number of pulses or conductive states required to complete a periodic change in magnetic field, represented by m, or the number of pulses required for the motor to rotate one pitch angle.

Maintaining torque: refers to the torque at which the stator locks the rotor when the stepper motor is powered on but not rotating.

Step angle: corresponding to a pulse signal, the angular displacement of the motor rotor rotation.

Positioning torque: The locking torque of the motor rotor itself when the motor is not powered.

Out of step: The number of steps taken by the motor during operation is not equal to the theoretical number of steps.

Misalignment angle: The angle at which the rotor tooth axis deviates from the stator tooth axis, and there must be an misalignment angle during motor operation. The error caused by the misalignment angle cannot be solved by using subdivision drive.

Operating torque frequency characteristics: The curve of the relationship between the output torque and frequency measured during the operation of a motor under certain testing conditions.

Characteristics of stepper motors

The accuracy of a general stepper motor is 3-5% of the step angle and does not accumulate;

The maximum temperature allowed on the surface of a stepper motor depends on the demagnetization point of different magnetic materials used in the motor;

The torque of a stepper motor will decrease with the increase of speed (U=E+L (di/dt)+I * R)

Idle starting frequency: refers to the pulse frequency at which a stepper motor can start normally under no-load conditions. If the pulse frequency is higher than this value, the motor cannot start normally and may experience step loss or stalling.

The starting speed of stepper motors is generally between 10-100RPM, while the starting speed of servo motors is generally between 100-300RPM. Depending on the size and load of the motor, larger motors generally correspond to lower starting speeds.

Low frequency vibration characteristics: The stepper motor operates repeatedly while moving in a continuous step state. The movement of its step state will generate a 1-step response.

When the stepper motor is constant, the voltage value supplied to the driver has a significant impact on the motor performance. The higher the voltage, the greater the torque that the stepper motor can generate, which is more conducive to high-speed applications. However, the heating of the motor increases with the increase of voltage and current, so it is important to note that the temperature of the motor should not exceed the maximum limit.