STM28-MC Integrated Stepper Servo Motor

Low‑inertia motors have very low rotor inertia, offering faster acceleration and better dynamic response. High‑inertia motors provide higher torque accuracy, lower speed fluctuation, and smoother operation – they are suitable for applications that prioritise running stability.

Microstepping is essentially an electronic damping technique, primarily designed to reduce or eliminate low‑frequency vibration. Improved positional resolution is a secondary benefit. Different manufacturers’ microstepping drivers can vary greatly in accuracy, and higher microstepping numbers are harder to control precisely.

This is due to the motor’s pull‑in rate – the maximum pulse frequency at which it can start from standstill without losing steps. If the pulse frequency exceeds this rate, the motor cannot start properly and may lose steps or stall. The solution is to use an acceleration ramp: start at a low frequency and gradually increase to the target high frequency. Integrated stepper motors allow you to set acceleration and deceleration parameters freely.

When the motor rotates, the inductance in each phase winding generates a back‑EMF. The higher the frequency, the greater the back‑EMF, which reduces the phase current and thus lowers the torque.

Excessive temperature can demagnetise the magnetic material, reducing torque and causing step loss. The demagnetisation point is generally above 130°C, some up to 200°C. Therefore, a surface temperature of 80‑90°C is perfectly normal for a stepper motor. The most common insulation class is Class B, with a rated operating temperature up to 130°C.