Closed-Loop Stepper Motors
Closed-loop stepper motors combine the affordability and simplicity of stepper motor technology with the position feedback and reliability of servo systems. By integrating a 1000-line incremental encoder directly into the motor, these systems provide real-time position verification to the driver, which continuously monitors and corrects the rotor position. This closed-loop feedback eliminates the risk of missed steps — the primary limitation of open-loop stepper systems — while maintaining the high holding torque, smooth low-speed operation, and cost advantages inherent to stepper motors.
Compared to open-loop operation, closed-loop stepper motors offer several significant advantages: up to 50% more usable torque at high speeds, reduced motor heating and vibration, quieter operation, and virtually silent idle holding. The encoder feedback allows the driver to reduce current when the motor is stationary (reducing heating) and instantly detect and correct any position deviation. This makes closed-loop stepper motors ideal for applications where positional integrity is critical but the higher cost of full servo systems is not justified.
Available Models
Closed-Loop Motors (with Encoder)
| Model | Frame Size | Holding Torque Range | Encoder Resolution |
|---|---|---|---|
| NEMA17 (17IE) | 42mm × 42mm | 0.48 - 0.72 N·m | 1000 lines |
| NEMA23 (23IE) | 57mm × 57mm | 1.20 - 2.00 N·m | 1000 lines |
| NEMA24 (24IE) | 60mm × 60mm | 1.50 - 3.00 N·m | 1000 lines |
| NEMA34 (34IE) | 86mm × 86mm | 4.50 - 8.50 N·m | 1000 lines |
Integrated Motors (IG Series)
All-in-one solutions combining motor, driver, and encoder in a single housing — NEMA8 through NEMA34.
RS485/Modbus Integrated (AR Series)
Integrated stepper motors with RS485 or Modbus RTU communication for networked motion control.
Absolute Encoder Motors
Integrated motors with absolute encoders that retain position information after power loss.
Special
- EtherCAT Stepper Motor — Real-time industrial Ethernet communication
- Bluetooth to RS485 Converter — Wireless control over standard RS485 networks
Key Benefits
| Benefit | Description |
|---|---|
| No Missed Steps | Encoder feedback ensures positional integrity at all times |
| Higher Speed Torque | Up to 50% more torque at high speeds compared to open-loop |
| Reduced Heating | Automatic current reduction during hold and low-load conditions |
| Lower Vibration | Smooth microstepping with active damping from encoder feedback |
| Quiet Operation | Near-silent operation, especially at low speeds and hold |
| Drop-in Replacement | Same mounting dimensions as open-loop equivalents |
Related Documentation
Last updated: 2026-05-28