Hobby servo (RC)
| Control | 50 Hz PWM, pulse 1–2 ms (1.5 ms = center) |
|---|---|
| Range | ~180° typical (360° continuous variant loses position feedback) |
| Power | Micro 4.8–6 V / ~100 mA; standard 6 V / 1 A peak |
| Wiring | Orange=signal, red=+V, brown/black=GND |
Stepper motor
| Step size | Typical 1.8°/step (200 steps/rev); 0.9° in high-precision |
|---|---|
| Microstepping | 16× or 32× common — smoother, slightly lower torque |
| Unipolar vs bipolar | Bipolar is standard for CNC (4 wires, full coil use) |
| Common size | NEMA 17 for 3D printers, NEMA 23 for CNC |
| Drivers | A4988 (1.5 A), DRV8825 (2.5 A), TMC2209 (silent, StealthChop) |
| Torque drop | Falls with speed — holding torque spec is at zero RPM |
BLDC
| Control | Three-phase, ESC or FOC driver — commutation by hall or sensorless |
|---|---|
| Kv rating | RPM per volt under no load |
| Typical use | Drones, e-bikes, HDD spindles, modern appliance fans |
When to pick
| Need | Motor type |
|---|---|
| Precise position, hold power | Stepper (open-loop) or servo |
| Smooth continuous rotation | BLDC or DC brushed |
| Small angle, fast | Hobby RC servo |
| High torque at low speed | Stepper with gearbox |
| Low EMI, quiet | BLDC with FOC / stepper with StealthChop |
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