360° Continuous Rotation Servo
Modified servo that spins continuously like a geared motor.
A servo modified for full continuous rotation rather than fixed-angle positioning, useful as a simple speed-controlled wheel drive.
Specifications
| Operating voltage | 4.8V - 6V DC (5V typical) |
| Control signal | PWM, 50Hz, 1ms-2ms pulse width — but the pulse now sets speed and direction, not angle |
| Neutral point | ~1.5ms pulse = stopped; shorter/longer pulses spin one way or the other, further from 1.5ms = faster |
| Positioning | None — fully open-loop, no feedback on shaft angle, only continuous rotation |
| Typical no-load speed | ~50-60 RPM, varies by donor servo and how it was modified |
| Weight | ~9g-55g depending on donor servo (SG90-based vs MG996R-based) |
Pinout
| Pin | Name | Description |
|---|---|---|
| 1 | GND | Ground — usually the brown or black wire |
| 2 | VCC | Power, 4.8V-6V DC — usually the red wire |
| 3 | Signal | PWM control input — usually the orange or yellow wire |
Every unit's stop point drifts slightly from the textbook 1.5ms. Sweep 1.3ms-1.7ms in code once and hard-code the value that actually stops your specific servo.
Variants
A continuous rotation servo is convenient because it uses the exact same single-wire PWM signal as a positional servo, making it an easy drop-in for simple wheeled robots without adding a separate motor driver. For anything beyond a basic two-wheel rover, though, a dedicated gear motor and driver combo gives finer speed control and better efficiency than a servo that's been hacked to spin continuously.
| Variant | Price |
|---|---|
| Continuous rotation servo (this listing) | ~$2-5 |
| Standard SG90/MG90S servo | ~$1-4 |
| TT/N20 gear motor + driver | ~$3-8 (motor) + ~$2-5 (driver) |