The 42mm Two Phase Hollow Shaft Stepper Motor comes in Two different specifications. The specific parameters are shown in the table below. You can download the corresponding PDF to view the product dimension drawings below the table.
| Specification | SMK1702 | SMK1704 |
|---|---|---|
| Phase | 2 | 2 |
| Step Angle | 1.8° | 1.8° |
| Step Angle Error (No Load) | ±0.09° or below | ±0.09° or below |
| Current | 1.5 A | 2.5 A |
| Resistance (Phase) | 1.56 Ω ±10% | 0.8 Ω ±10% |
| Inductance (Phase) | 2.4 mH ±20% | 1.4 mH ±20% |
| Holding Torque | 0.26 N·m | 0.5 N·m |
| Rotor Inertia | ≈ 38 g·cm² | ≈ 77 g·cm² |
| Weight | ≈ 0.2 KG | N/A |
| Radial Runout | 0.025 mm (Load 450g) | 0.025 mm (Load 450g) |
| Axial Runout | 0.005 mm (Load 920g) | 0.075 mm (Load 920g) |
| Rated Operating Status | Continuous | Continuous |
| Lifetime (Hours) | Above 5000 H | Above 5000 H |
| Temperature Rise | Below 80 K | Below 80 K |
| Insulation Withstand Voltage | 500 V A.C. | 500 V A.C. |
| Insulation Resistance | Above 100 MΩ | Above 100 MΩ |
| Insulation Class | B | B |
| Operating Temperature Range | 0°C ~ +50°C | -20°C ~ +50°C |
| Operating Humidity Range | 20% RH ~ 90% RH | 20% RH ~ 90% RH |
| Storage Temperature Range | -20°C ~ +70°C | -20°C ~ +70°C |
| Storage Humidity Range | 15% RH ~ 95% RH | 15% RH ~ 95% RH |
| Technical parameter drawing |



