Closed-loop stepper motor
Oriental Motor AlphaStep AZ Series closed-loop stepper motors
Closed-loop stepper motor and driver packages with a battery-free mechanical absolute encoder, AC or 24/48 VDC drivers and EtherCAT, EtherNet/IP or PROFINET options; frames from 28 mm (0.095 N·m) to 85 mm (4 N·m on the motors checked).
Key specifications
| Ingress protection | IP40 (28 mm) to IP66 (85 mm), excluding mounting surface and connector |
|---|---|
| Temperature | 0–40 °C |
| Frame sizes | 28 to 85 (frames checked) |
| Supply | AC drivers 100-120 VAC or 200-240 VAC; DC drivers 24/48 VDC |
| Feedback | battery-free mechanical absolute encoder, +/-900 revolutions from home |
| Fieldbus | EtherNet/IP, EtherCAT, PROFINET; DC types also SSCNETIII/H, MECHATROLINK; RS-485 on some types |
| Holding torque | 0.095–4 Nm |
| Accuracy | stopping accuracy +/-0.05 deg typical (no load) |
Summarised in our own words from ORIENTAL MOTOR CO., LTD.'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2 · Source 3
Notes on this data
Holding torque max (4 N·m) is the largest figure found on the item pages checked (AZM911AC); not confirmed as the series maximum. Geared versions give higher output torque.
Specify Motion is not affiliated with ORIENTAL MOTOR CO., LTD.. Oriental Motor and AlphaStep AZ Series closed-loop stepper motors are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with an Oriental Motor part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
2-phase closed-loop stepper motors with built-in incremental encoders that replace the ES-M easy-servo line; brake, IP65 and imperial-shaft versions.
| Published maximum | AlphaStep AZ Series closed-loop stepper motors | Leadshine CS-M Series |
|---|---|---|
| Holding torque | 4 Nm | 12 Nm meets or exceeds |
| Current | — | 6 A |
3-phase high-voltage closed-loop steppers in NEMA 34/42 (catalogue also lists 17/23) for 220 VAC ES2 drives, 8-20 Nm.
| Published maximum | AlphaStep AZ Series closed-loop stepper motors | Leadshine ES2-MH Series (3-phase high … |
|---|---|---|
| Holding torque | 4 Nm | 20 Nm meets or exceeds |
| Current | — | 6 A |
57/60 mm 2-phase hybrid stepper, 1-4 Nm, mostly 8-lead for series or parallel wiring, for CNC and automation axes.
| Published maximum | AlphaStep AZ Series closed-loop stepper motors | NEMA 23 High Torque (M57STH / M60STH) |
|---|---|---|
| Holding torque | 4 Nm | 4 Nm meets or exceeds |
| Current | — | 4 A |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What a closed-loop stepper motor is
A closed-loop stepper is a hybrid stepper motor fitted with an encoder and run by a drive that uses the feedback to correct position and adjust current. If the load causes the rotor to lag, the drive detects the error and corrects it rather than losing steps silently. Many drives also reduce current when torque is not needed, lowering heat and noise. The motor keeps the stepper's strong low-speed torque but gains some servo-like behaviour.
When engineers choose a closed-loop stepper motor
Choose a closed-loop stepper when an open-loop stepper is nearly right but missed steps, heat or noise are a concern, such as varying loads, fast indexing or machines that must report a fault. It is typically cheaper and simpler than a servo. The trade-offs are high-speed performance and dynamics: torque still falls at speed, and peak acceleration is lower than a servo. For high-speed, high-dynamic axes, a servo remains better.
How to specify the Oriental Motor AlphaStep AZ Series closed-loop stepper motors
Send these with your enquiry and an engineer can confirm the right AlphaStep AZ Series closed-loop stepper motors variant or an equivalent:
- Holding torque and torque at speed (Nm, rpm)
- Frame size (NEMA or mm)
- Encoder resolution (counts per revolution)
- Drive voltage and current (V, A)
- Control interface: pulse, fieldbus or Ethernet
- Fault outputs and alarm handling
- Brake and IP options
Common mistakes to avoid
- Assuming closed loop gives servo performance at high speed
- Not wiring the drive alarm output to the controller
- Using an encoder resolution the drive does not support
- Ignoring tuning settings for heavy loads
Oriental Motor AlphaStep AZ Series closed-loop stepper motors: frequently asked questions
What is the Oriental Motor AlphaStep AZ Series closed-loop stepper motors?
Closed-loop stepper motor and driver packages with a battery-free mechanical absolute encoder, AC or 24/48 VDC drivers and EtherCAT, EtherNet/IP or PROFINET options; frames from 28 mm (0.095 N·m) to 85 mm (4 N·m on the motors checked). Published series figures include temperature 0 °C, temperature 40 °C, holding torque 0.095 Nm, holding torque 4 Nm. It is made by ORIENTAL MOTOR CO., LTD.; Specify Motion can help source it or propose an equivalent.
Who makes the Oriental Motor AlphaStep AZ Series closed-loop stepper motors?
The Oriental Motor AlphaStep AZ Series closed-loop stepper motors is made by Oriental Motor (ORIENTAL MOTOR CO., LTD.) and is listed here for engineers comparing options. Specify Motion is not affiliated with ORIENTAL MOTOR CO., LTD.; brand names are used only to identify the product.
What is the temperature of the Oriental Motor AlphaStep AZ Series closed-loop stepper motors?
The published series minimum temperature is 0 °C. Individual models and sizes in the AlphaStep AZ Series closed-loop stepper motors range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Oriental Motor AlphaStep AZ Series closed-loop stepper motors?
Yes. On published figures, Leadshine CS-M Series and Leadshine ES2-MH Series (3-phase high voltage) are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What is the difference between a closed-loop stepper and a servo?
Both use feedback, but a closed-loop stepper keeps the stepper's high pole count, giving strong low-speed torque and a stepper-style drive, while a servo motor is optimised for high speed and dynamics. Closed-loop steppers are usually cheaper and simpler to set up; servos usually perform better at high speed.
Do closed-loop steppers run cooler?
Often, yes. Many closed-loop drives reduce current when less torque is needed, while open-loop drives run full current regardless. This lowers motor temperature and noise. The benefit depends on the drive and the load profile, so check the drive's current control mode.
Further reading: Closed loop stepper motors explained · Servo vs stepper · Servo and stepper motors
Other closed-loop stepper motor series
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