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AW20HS Series — NEMA 8 Closed Loop Hybrid Stepper Motor
The AW20HS series is Apexwell's smallest closed loop stepper motor platform, pairing a NEMA 8 (20mm) hybrid stepper with an integrated encoder for real-time position feedback. Offered across three body lengths from 30mm to 42mm, the series targets applications where board space is tight but silent step loss still isn't acceptable — a common gap for compact robotics and instrument designs that outgrow open-loop steppers.
Shared Specifications (all models)
| Parameter | Value |
|---|---|
| Step Angle | 1.8° |
| Step Accuracy | ±5% |
| Lead Wires | 4 (bipolar) |
| Insulation Class | Class B (130°C) |
| Temperature Rise | 50K Max |
| Ambient Temperature | -20°C to +50°C |
| Insulation Resistance | ≥100 MΩ (500 VDC) |
| Dielectric Strength | 500 VAC, 1 minute |
| Encoder Resolution | 500 / 512 / 1000 / 1024 / 2000 PPR (selectable) |
Model Comparison
| Model | Body Length | Phase Current | Phase Resistance | Phase Inductance | Holding Torque | Rotor Inertia | Mass |
|---|---|---|---|---|---|---|---|
| AW20HS30-0504A | 30 mm | 0.5 A | 4.8 Ω | 1.3 mH | 0.011 N·m | 2.1 g·cm² | 0.05 kg |
| AW20HS38-0604A | 38 mm | 0.6 A | 6.5 Ω | 1.7 mH | 0.018 N·m | 3.0 g·cm² | 0.06 kg |
| AW20HS42-0504A | 42 mm | 0.5 A | 5.2 Ω | 1.8 mH | 0.020 N·m | 3.8 g·cm² | 0.09 kg |
Closed Loop Feedback
Every AW20HS motor ships with an encoder as standard, selectable in five resolutions from 500 to 2000 PPR, letting the driver continuously verify actual rotor position against the commanded position. This is the same feedback principle we covered in our article on why-closed-loop-stepper-motors-are-replacing-traditional-steppers — at NEMA 8 scale, it means micro-precision mechanisms can get stall detection and positioning confidence without moving up to a larger frame size.
Typical Applications
The AW20HS's compact NEMA 8 footprint suits camera and lens focus mechanisms, small robotic grippers, medical instrument positioning, and other micro-precision designs where a NEMA 11 or larger stepper simply won't fit, but open-loop step loss risk isn't acceptable either.
Why Choose the AW20HS Series
At this frame size, few suppliers offer closed loop feedback at all — most compact steppers are open-loop only. The AW20HS closes that gap, giving designers encoder-verified positioning in one of the smallest closed loop stepper packages Apexwell offers. Custom shaft length and connector configurations are available on request.
We can customize the electrical parameters of the motor and geometric dimensions such as the motor output shaft size according to customer requirements. Accessories including pulleys, eccentric gearboxes, planetary gearboxes and encoders can also be added. For more products and detailed specifications, please download the product catalog from the Download Center.
