Types of Stepper Motor

Stepper motors come in several distinct types, each engineered to meet specific performance requirements in terms of torque, precision, speed, and application suitability. The three main types of stepper motors are:

1. Permanent Magnet Stepper Motor (PM Stepper)

The Permanent Magnet Stepper Motor uses a permanent magnet rotor and operates based on the attraction and repulsion between the stator’s electromagnets and the rotor’s magnetic field.

Construction:

• Rotor is made of permanent magnets (north and south poles).

Step Angle:

• Typically 7.5° to 15° per step.

Torque:

• Moderate holding torque.

Advantages:

• Simple construction.

• Cost-effective.

• Suitable for low-speed applications.

Applications:

• Consumer electronics, toys, small devices, analog instruments.

2. Variable Reluctance Stepper Motor (VR Stepper)

The Variable Reluctance Stepper Motor operates based on the principle that the rotor moves to a position where the magnetic reluctance is minimum.

Construction:

• Rotor has no magnets—only soft iron laminations with teeth.

Step Angle:

• Typically 5° to 15°, allowing for more steps per revolution.

Torque:

• Lower torque compared to other types.

Advantages:

• High step resolution.

• No permanent magnets—less expensive and lightweight.

Applications:

• Printers, scanners, instrumentation with low torque needs.

3. Hybrid Stepper Motor (HB Stepper)

The Hybrid Stepper Motor combines the features of both PM and VR stepper motors to deliver high performance, precision, and torque.

Construction:

• Rotor has both permanent magnets and toothed structure, improving alignment and magnetic coupling.

Step Angle:

• Usually 1.8° (200 steps per revolution) or 0.9° (400 steps per revolution).

Torque:

• High torque and holding power.

Advantages:

• Excellent resolution and accuracy.

• Smooth rotation and better efficiency.

• Widely compatible with microstepping.

Applications:

• Industrial automation, CNC machines, robotics, 3D printers, medical devices.

Comparison Table

Type	Step Angle	Torque	Precision	Common Use Cases
Permanent Magnet	7.5° – 15°	Moderate	Low	Toys, indicators, small gadgets
Variable Reluctance	5° – 15°	Low	High	Scanners, basic automation
Hybrid	0.9° – 1.8°	High	Very High	CNC, robotics, 3D printers, medical

Summary

Each type of stepper motor has unique strengths:

• Choose Permanent Magnet Stepper Motors for cost-sensitive, low-performance applications.

• Select Variable Reluctance Stepper Motors for higher resolution and light-duty automation.

• Opt for Hybrid Stepper Motors when precision, torque, and reliability are critical.

Selecting the correct stepper motor type ensures your system operates efficiently, accurately, and within budget.