Hybrid stepper motor
NEMA 11 High Torque (M28STH) hybrid stepper motor
28 mm 2-phase hybrid stepper offered in 28-51 mm body lengths, aimed at small automation and robotics axes where size and cost matter.
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What are you specifying?
Select everything you need. A motor, drive and gearbox can be specified together as one axis.
Key specifications
| Frame sizes | 28 mm |
|---|---|
| Feedback | none (open loop); optical encoder option |
| Current (max) | 0.95 A |
| Holding torque | 0.042–0.118 Nm |
| NEMA sizes | 11 |
| Step angle | 1.8 ° |
| Rated current range | 0.35-0.95 |
| Rated voltage range | 2.52-4.56 |
| Length range | 28-51 |
| Leads | 4, 6 |
| Phases | 2 |
Series ranges as published; individual models vary. The full datasheet, drawings and CAD models are available on request.
Options
- single or double shaft
- optical encoder
- planetary gearbox
- custom windings
- alternative mounting flanges
- extended torque range on request
Typical applications
What a hybrid stepper motor is
A hybrid stepper motor moves in fixed angular steps, typically 1.8° or 200 full steps per revolution, as a drive switches current through its windings in sequence. It combines a permanent-magnet rotor with toothed iron stator and rotor sections, giving high holding torque and fine resolution. With a microstepping drive, each full step is split into smaller steps for smoother motion. Steppers usually run open loop, so position is known by counting steps rather than measured.
When engineers choose a hybrid stepper motor
Choose a hybrid stepper for low-cost, simple positioning at low to moderate speed, such as indexing, dosing, small axes and instruments. It holds position strongly at standstill and needs no tuning. The trade-offs are falling torque at speed, resonance and possible lost steps if overloaded. Where speed is high, loads vary or a missed position would cause a fault, a closed-loop stepper or servo is safer.
How to specify the NEMA 11 High Torque (M28STH)
Send these with your enquiry and an engineer can confirm the right NEMA 11 High Torque (M28STH) variant:
- Holding torque (Nm)
- Torque needed at operating speed (Nm at rpm)
- Frame size (NEMA or mm)
- Step angle (°)
- Phase current and inductance (A, mH)
- Drive voltage (V)
- Shaft, encoder and IP options
Common mistakes to avoid
- Sizing on holding torque instead of the pull-out curve
- Driving with too low a supply voltage, losing high-speed torque
- Leaving out torque margin, typically 30% to 50%
- Ignoring resonance in the mid-speed range
NEMA 11 High Torque (M28STH): frequently asked questions
Can you help replace NEMA 11 High Torque (M28STH) or source the original?
Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.
What is the NEMA 11 High Torque (M28STH)?
28 mm 2-phase hybrid stepper offered in 28-51 mm body lengths, aimed at small automation and robotics axes where size and cost matter. Published series figures include frame sizes 28 mm, current 0.95 A, holding torque 0.042 Nm, holding torque 0.118 Nm. It is available through our supply network, and our engineers can confirm the right variant for your application.
Who makes the NEMA 11 High Torque (M28STH)?
The NEMA 11 High Torque (M28STH) is part of a range available through our supply network. Send us your requirement for pricing, lead time, datasheets and CAD.
What is the frame sizes of the NEMA 11 High Torque (M28STH)?
The published series maximum frame sizes is 28 mm. Individual models and sizes in the NEMA 11 High Torque (M28STH) 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.
Why do stepper motors lose torque at high speed?
Winding inductance limits how fast current can rise each step. As speed increases there is less time per step, so current and torque fall. A higher drive voltage raises current faster and extends the torque curve. Always size from the pull-out torque curve at your drive voltage.
Does microstepping increase accuracy?
Microstepping makes motion smoother and gives finer resolution, but accuracy is not improved in proportion. Each microstep produces only a small torque increment, so load torque can shift the actual position. Accuracy is mostly set by the motor's step accuracy and the load.
Further reading: How to select a stepper motor · Servo vs stepper · Servo and stepper motors
Often compared with
Engineers specifying this series often compare it with:
Other hybrid stepper motor series
Engineer support
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How it works
From enquiry to delivery
Send a part number or describe the application. Our engineers take it from there: the right product, a clear quotation, and delivery and support arranged.
- 01Tell us what you needSend a part number, or configure the application, quantities and timing.
- 02An engineer reviews itWe check the specification and find the original part, a checked equivalent or a complete axis.
- 03Receive your quotationProducts, pricing, lead time and compatibility notes in one reply.
- 04Order and deliveryWhen you are happy, the order is placed and delivery and after-sales support are arranged.