Stepper Motors

Stepper motors, also known as stepping motors, are electric DC motors that move in steps. Electricity is converted into rotation, with each pulse of electricity turning the motor by one step. Precise control of how far and how fast the motor moves is easily determined, especially for computer-controlled motors.

For more information, check out our comprehensive guide to stepper motors.

Benefits of Using a Stepper Motor

Excellent Torque at Low Speeds

Stepper motors provide high torque even at low speeds, making them ideal for applications requiring precise, controlled movement without significant speed reduction.

Precise Positioning

Their ability to move in discrete steps allows for highly accurate and repeatable positioning, crucial for applications requiring exact motion control.

Long Lifespan

Due to their brushless design and reliance on electromagnetic forces over physical commutation, stepper motors typically have long operational lifespans and require minimal maintenance.

Flexible Application

Stepper motors are versatile and can be used in a wide range of applications, from CNC machinery to medical devices.

Low-Speed Synchronous Rotation

Electric stepper motors can maintain synchronous rotation at low speeds without the need for complex feedback systems, simplifying control in many applications.

Reliability

Stepper motors are generally very reliable in operation due to their simple design and lack of contact brushes, which significantly reduce wear and tear.

Mechanics of Stepper Motors

Stepper motors operate by converting electrical pulses into precise mechanical movements through the sequential energisation of electromagnetic coils (stator windings) that surround a toothed rotor. Each pulse causes the rotor to advance by a single step, as it aligns with the magnetic field generated by the energised coils. DC stepper motors are suited for accurate and repeatable movements, and are widely used in 3D printers, CNC machines, and robotics.

Types of Stepper Motors

Bipolar Stepper Motors

Bipolar stepper motors contain an onboard driver that uses an H bridge circuit to reverse current flow on a phase-by-phase basis. Bipolar motors are generally better than unipolar motors, in terms of torque and efficiency because they are able to use both AC and DC currents. Bipolar stepper motors use electromagnetic coils which are energised on command, to turn a shaft. Using this system, the shaft can be turned in measured movements, and also be reversed when needed.

Hybrid Stepper Motors

Combining features of permanent magnet and variable reluctance motors, hybrid steppers provide high torque, high step resolution, and good speed performance. This makes them suitable for demanding applications like robotics, medical devices, and industrial automation where both precision and power are critical.

Permanent Magnet Stepper Motors

Permanent magnet stepper motors are electromechanical energy conversion devices that convert electrical energy to mechanical energy. They offer good holding torque even when unenergised and are known for their simplicity and cost-effectiveness. They are commonly employed in printers, scanners, and camera lenses for moderate-precision applications.

Transmission Stepper Motors

Transmission stepper motors are often integrated with a gearbox or transmission system. This combination increases output torque and reduces speed, making them ideal for applications requiring high torque at low speeds, such as in continuously variable transmissions (CVTs) in vehicles, or other systems that require enhanced mechanical advantage.

High Precision Stepper Motors

These advanced motors are utilised in semiconductor manufacturing, precision optical instruments, and scientific equipment where even minute positional errors are unacceptable. Their ability to deliver exceptional accuracy and repeatability comes from their incorporation of finer step angles and advanced microstepping abilities.

Industrial Applications of Stepping Motors

• CNC Machines: Stepper motors control the precise movement of cutting tools and workpieces in CNC mills, lathes, and routers.
• 3D Printers: Electric stepper motors accurately position the print head and control filament extrusion in additive manufacturing processes.
• Robotics: Stepper motors are used for precise joint articulation and end-effector positioning in industrial robots.
• Packaging Machinery: They manage the accurate feeding, sealing, and cutting operations in various packaging lines.
• Textile Manufacturing: Stepper motors control thread tension, needle positioning, and fabric movement in weaving and knitting machines.
• Medical Devices: They provide precise fluid dispensing, sample positioning, and optical alignment in laboratory automation and diagnostic equipment.
• Automated Assembly Lines: Stepper motors enable accurate component placement and indexing in automated manufacturing processes.
• Printing Equipment: They control paper feeding, print head positioning, and ink application in commercial and industrial printers.

How to Choose the Right Electric Stepper Motor

Here's a quick primer on how to choose the correct stepper motor for various applications:

• Determine Required Torque: Calculate the necessary holding, running, and accelerating torque for your application, including friction and load, to ensure the motor can move the intended mass.
• Define Step Angle/Resolution: Select a step angle that provides the required positional accuracy and smoothness of motion for your application's precision needs.
• Evaluate Speed Requirements: Ensure the motor can achieve and maintain the necessary rotational speed for the application's operational demands.
• Assess Environmental Conditions: Choose a motor with the appropriate IP rating and temperature range for the operating environment's dust, moisture, and temperature variations.
• Ensure Driver Compatibility: Select a motor compatible with your stepper motor drivers in terms of voltage, current, and control signals (e.g., bipolar vs. unipolar).
• Account for Inertia Matching: Aim for a motor-to-load inertia ratio that minimises resonance and maximises system performance and stability.
• Consider Physical Size and Mounting: Verify the stepper motor's dimensions and mounting options fit within the available space and mechanical design of the system.
• Budgetary Concerns: Balance performance requirements with cost-effectiveness, as higher precision and torque often come with a higher price tag.

Leading Supplier and Distributor of Stepper Motors in Australia

RS is Australia's top source of 24V stepper motors, stepping motors and stepper electric motors. We are the supplier and distributor of high-quality products from industry stalwarts such as RS PRO, Sanyo Denki and Festo. We also carry electric motor peripherals, such as AC motors and motor starters.

Buy high precision stepper motors online today and enjoy free next day delivery. For more details on our delivery processes, visit our delivery page.