Motion control is at the heart of modern industrial automation. From assembly lines requiring extremely precise positioning to collaborative robots and medical devices, every application demands accurate, repeatable, and time-stable motion. In this context, the stepper motor stands out as one of the most widely adopted technologies, thanks to its ability to achieve precise positioning even in open-loop systems—translating electrical pulses into exact mechanical displacements—offering an excellent performance-to-cost ratio. This guide explores its structure , physical principles , types, and applications, providing a complete overview for engineers, designers, and OEMs seeking to understand the full potential of this technology.
INDEX
1. The role of stepper motors in industrial automation
2. Structure and operating principle
3. Unipolar and bipolar stepper motors
4. Hybrid stepper motor
5. Advantages and limitations of stepper motors
6. Control and driving methods
7. Industrial applications
8. Stepper motor vs. brushless motor
9. Integration with Ever Motion Solutions drivers and control systems
10. Selecting the right motor for your application
11. Trends and innovations in motion control
12. Why stepper motors remain a strategic choice in motion control
1. The role of stepper motors in industrial automation
In industrial automation, motion control is a key factor for ensuring productivity, precision, and reliability. Every automated line, assembly robot, or dosing system relies on the ability to position and move components with consistent accuracy over time. In this context, the stepper motor plays a strategic role: combining structural simplicity, direct load control, and high positioning performance, it is one of the most widespread motion control solutions.
This type of motor is used in a wide range of applications: from pick & place systems and 3D printers , to Cartesian robots compact CNC machines , medical devices , and measuring instruments . Its ability to move in precise angular increments and maintain position without feedback sensors makes it ideal for open-loop systems, where accuracy is required without added complexity or cost. Each pulse sent to the motor corresponds to a defined movement of the shaft—a simple yet powerful principle enabling digital motion control .
2. Structure and operating principle
A stepper motor is a synchronous electric motor in which the shaft rotation occurs in discrete angular increments, called “steps".Unlike DC motors, which rotate freely, a stepper moves in predetermined increments, allowing direct and recise position control
Its basic structure consists of three main elements:
- Stator: composed of multiple electrical windings arranged in phases (typically two or four). Sequential energizing of these windings generates alternating magnetic fields that drive the rotor. The stator features salient poles that align precisely with the rotor;
- Rotor: made of permanent magnets and ferromagnetic materials, with salient poles aligning with those of the stator. Its configuration determines the torque and precision of the motor;
- Control system: the driver or electronic circuit managing the coil excitation sequence, determining direction, speed, and microstepping resolution.
The motor operates based on the magnetic interaction between stator and rotor. When a coil is energized, the rotor aligns with the magnetic field generated. Sequential activation of the coils produces continuous rotary motion divided into discrete steps. Standard stepper motors provide 200 steps per revolution (1.8° per step), but with microstepping technology, resolutions can reach up to 1/256 step (0.007°), ensuring extremely smooth and silent movement.
3. Unipolar and Bipolar Stepper Motors
Stepper motors are generally classified into two types: unipolar and bipolar, differing in how their phases are powered.
The unipolar motor (typically with 6 wires)features a common center tap in each phase, allowing polarity reversal without changing the current direction. This simplifies control and reduces driver complexity, making it a cost-effective and easy-to-integrate solution. However, since only half of each winding is active at a time, available torque is reduced.
The bipolar motor, by contrast, allows current to flow in both directions through the entire winding of each phase. This provides higher torque and better magnetic efficiency but requires more complex electronics, typically using H-bridge circuits for current commutation.
In industrial settings, bipolar stepper motors are the preferred choice where torque, precision, and motion dynamics are critical. Unipolar models remain common in compact or low-cost devices, where ease of control is prioritized.
4. Hybrid Stepper Motor
The hybrid stepper motor represents the most advanced and versatile version of this technology, combining the benefits of variable reluctance and permanent magnet stepper designs. The rotor consists of two toothed sections offset by half a tooth pitch, one magnetized as the north pole and the other as the south pole. This configuration increases magnetic flux density and therefore torque, for the same overall dimensions.
Thanks to their superior performance, hybrid stepper motors are the most commonly used, across applications. Available in standard NEMA sizes (8, 17, 23, 34, 42, etc.), they can integrate incremental or absolute encoders , electromagnetic brakes or gearboxes pallowing adaptation to any control need, including closed-loop configurations. Ever Motion Solutions offers hybrid stepper versions with IP65 protection , suitable for harsh industrial environments where dust or liquid contamination is frequent.
5. Advantages and Limitations of Stepper Motors
Main Advantages:
- Precise position control without encoders
- High torque at low speed
- Excellent repeatability and stability
- Robust construction and long service life
- Easy integration with digital dirvers
Main Limitations:- Torque loss at high speed
- Possible mechanical vibrations and resonances
- No direct position feedback in open-loop systems
- Lower efficiency than brushless motors in certain applications
In recent years, these limitations have been overcome with the introduction of hybrid vector closed-loop, also available with integrated electronics. Ever Motion Solutions systems represent the state of the art in stepper technology, combining the simplicity of stepper motors with the dyanmic performance of servomotors improving overall efficiency and stability even under variable load conditions.
6. Control and driving methods
The dynamic behavior dof a stepper motor depends heavily on the driver and the type of control used. The main operating modes are:
- Full-step: each electrical pulse corresponds to a full 1.8° step, providing maximum torque but more vibration.
- Half-step: the rotor advances by half steps (0.9° per pulse), improving resolution and motion smoothness.
- Microstepping: divides each step into smaller fractions (1/8, 1/16, up to 1/256), reducing vibrations and enabling extremely smooth and precise movements.
Ever Motion Solutions' programmable drivers support all these modes and can be integrated with PLCs or industrial PCs via common interfaces sush as ETHERCAT, PROFINET, ETHERNET IP, POWERLINK, CANopen, MODBUS TCP and RTU . They allow users to configure custom speed, acceleration, and deceleration profiles , optimizing system response according to load and required dynamics. The us of intelligent, programmable drivers is now a key factor for achieving real-time motion performance, especially in multi-axis or high dynamic applications.
7. Industrial Applications
Stepper motors are highly versatile and are used across nearly all automation sectors, including:
- Packaging machinery;
- Linear and rotary labelling systems ;
- Assembly robots and pick&place units; CNC machines;
- Medical devices ;
- Industrial plotters;
- Control valves;
- Format change mechanisms
Their ability to maintain high torque even at zero speed makes them ideal for low-dynamic applications or systems with long static phases. In such cases, the motor can hold position with low current draw, minimizing energy consumption. When paired with advanced digital drivers , stepper systems enable intelligent torque management, reducing vibration, acoustic noise, and total power consumption compared to open-loop solutions.
Ever Motion Solutions designs motors and drivers that deliver smooth, stable, and reliable motion , ensuring direct integration into precision machinery, automated lines, and medical equipment where motion quality equals productivity.
8. Stepper Motor vs Brushless Motor
To better understand the value of stepper technology, it’s useful to compare it with brushless motors, another widely used motion control solution. A brushless motor is a A brushless motor is a synchronous DC motor without brushes, where current commutation is handled electronically. It offers higher efficiency, the ability to operate at high speed, and closed-loop feedback via sensors or encoders—ideal for dynamic or high-duty-cycle movements. However, it requires more complex and expensive control systems, while the stepper motor remains preferable for applications prioritizing open-loop precision, direct drive capability, and cost-effective performance.
The key differentiator is the direct relationship between command signal and mechanical position: unlike brushless or DC motors, which need continuous feedback, a stepper executes the exact number of commanded steps, ensuring consistent repeatability even without sensors. This feature is particularly valued in applications where repeatability matters more than speed—such as fluid dosing, electronic component handling, or small linear axis motion.
| Characteristic | Stepper Motor | Brushless Motor |
| Control | Open-loop or closed-loop | Always closed-loop |
| Torque at low speed | High | Medium |
| Maximum speed; | Limited | High |
| Position accuracy; | High (discrete) | High (Continuous) |
| Energy efficiency; | Medium | High |
| System cost; | Lower | Higher |
These are two different control philosophies: the stepper ensures precision and simplicity in discrete movements, while the brushless motor prioritizes speed and dynamics for continuous motion applications.
9. Integration with Ever Motion Solutions Drivers and Control Systems
Ever Motion Solutions offers a wide range of stepper motor drivers optimized for maximum torque output, low noise, and real-time motion response. The Titanio e Slimline series include programmable, fieldbus-integrated and open-frame - ideal for machine builders and OEMs requiring customized, reliable solutions.
Integrated electronic versions - comibining motor, encoder, driver, and control logic - represent one f the most significant innovations in recent years. They simplify wiring, reduce control cabinet space (especially in multi-axis systems) and speed up installation. This configuration is particularly advantageous in modular systems, mobile robots and portable medical devices , where compactness and low electromagnetic interference are crucial.
10. Selecting the Right Stepper Motor for Your Application
Choosing the right stepper motor depends on several parameters:
- Required torque (Nm);
- Operating speed (rpm);
- Position accuracy;
- Supply voltage and driver type;
- Mechanical size (NEMA standard);
- Ambient temperature and environmental conditions.
Ever Motion Solutions provides dedicated technical support to help designers and system integrators identify the optimal configuration - including waterproof, geared, brake-equippe, incremental encoder, or UL/ATEX-certified versions for demanding industrial environments.
11. Trends and Innovations in Motion Control
The future of motion control is moving toward the integration of smart motors, advanced sensors, and predictive analytics. Smart motion control technologies enable real-time monitoring of parameters such as temperature, vibration, current consumption, and position—allowing preventive maintenance and optimization of production cycles.
At the same time, integration with industrial networks and IoT protocols allows stepper motors to communicate with supervisory systems and dynamically adapt to operating conditions. Ever Motion Solutions is actively developing intelligent drivers capable of implementing automatic compensation algorithms and energy optimization, making motion control more efficient, flexible, and sustainable.
12. Why Stepper Motors Remain a Strategic Choice in Motion Control
Despite the emergence of more complex technologies, the stepper motor remains a cornerstone in motion control thanks to its reliability, simplicity, and versatility. It continues to evolve, perfectly integrating with modern electronics and advanced automation systems.
With nearly 50 years of experience, Ever Motion Solutions designs and manufactures in Italy a complete range of stepper motors, brushless motors, and industrial drivers, delivering high-performance solutions for every application—from packaging to robotics, medical to mechatronics.