What Is a Stepper Motor?
A stepper motor is a motor that divides its rotation into small fixed-angle steps, turning a certain angle with each electrical pulse. It provides precise position without feedback.
How Does It Work?
The coils around the motor are energized in a certain order; the rotor turns one step with each sequence. The pulse count sets the position, and the pulse rate sets the rotation speed.
Open-Loop Position
Since the step angle is known (e.g. 1.8° → 200 steps/rev), the position is found just by counting pulses; no feedback like an encoder is needed. So it's called "open-loop" position control.
| Property | Value |
|---|---|
| Step angle | Typically 1.8° (200/rev) |
| Type | Bipolar / unipolar |
| Drive | Full / half / microstep |
Microstepping
The driver divides each step into smaller sub-steps by gradually adjusting the coil currents. This gives smoother motion and higher resolution; it reduces vibration and noise.
Where Is It Used?
3D printers, CNC machines, scanners, cameras and systems needing precise positioning cheaply.
Holding Torque
A stepper fixes its position by keeping the coils energized even when stopped (holding torque). This is a strong advantage but, drawing continuous current, it causes heating and energy consumption.
Common Mistakes
- Missing steps: under excess load/speed the motor skips a step and the position is lost.
- Use without a driver: a stepper needs a special stepper driver.
- Heating: continuous current for holding torque creates heating.
Frequently Asked Questions
Why is no encoder needed?+
What's the difference from a servo?+
Search parts related to "What Is a Stepper Motor?"
Find the right part by comparing price, stock and distributors.