Pinout
Stepper motor (NEMA 17, bipolar, 4-wire) pinout
Pins
- A+ / A− — coil A (one winding)
- B+ / B− — coil B (the other winding)
Specifications
| Type | Bipolar hybrid stepper, 2 phases, 4 wires |
|---|---|
| Step angle | 1.8° (200 steps/rev) on most models; 0.9° versions exist |
| Rated current | Model-dependent, typically 0.4–2 A per phase |
| Holding torque | Model-dependent, typically 0.2–0.6 N·m |
| Face size | 42 × 42 mm (NEMA 17 standard) |
| Mounting holes | 4 × M3 on a 31 mm square |
| Pilot boss | 22 mm diameter |
| Shaft | 5 mm diameter |
| Body length | Model-dependent, roughly 20–60 mm |
| Driver needed | Bipolar current-limiting driver (A4988, DRV8825, TMC2209…) |
Notes
- Swapping A+/A− (or B+/B−) reverses that coil's direction — never connect a coil pair to two different phases. Find the pairs with an ohmmeter: the two leads of one coil read a few ohms, leads of different coils read open.
- Wire colours and the plug order are NOT standardised across makers (black/green + red/blue is common, but not universal) — the ohmmeter test beats the colour chart.
- NEMA 17 only fixes the face: 42 mm square, four M3 holes on a 31 mm square, 22 mm boss, 5 mm shaft. Length, current and holding torque vary with the model.
