Continuous Rotation Servos

Continuous rotation servos are standard hobby RC servos that have been modified to offer open-loop speed control instead of their usual closed-loop position control. The modification effectively turns them into motors with integrated motor drivers in a compact, inexpensive package. Just throw on a wheel and you have a drive system for your robot that can be controlled using an RC signal or a simple direct connection to a single microcontroller I/O line. The following table shows how our continuous rotation servos compare to each other.

Continuous rotation servo size comparison. From left to right: SpringRC SM-S4303R, Power HD AR-3606HB, FEETECH FS5106R, Parallax Feedback 360°, Parallax (Futaba S148), and FEETECH FS90R.

6 V 4.8 V Weight (g) Size (mm) Direction
vs pulse
(1ms → 2ms)
Digital? Feed­back? Price
Max speed
(RPM)
Stall torque
(oz·in)
Max speed
(RPM)
Stall torque
(oz·in)
SpringRC SM-S4303R 54 71 43 46 41  41.3 × 20.7 × 40.2  CW→CCW $15.95
SURPLUS SpringRC SM-S4303R 2-Pack 54 71 43 46 41  41.3 × 20.7 × 40.2  CCW→CW $19.95 for a pair of servos
FEETECH FS5106R 95 83 78 70 39  40.8 × 20.1 × 38.0  CW→CCW $15.95
Parallax Feedback 360° 140 35 41  40.0 × 20.0 × 37.2  CW→CCW yes yes $27.99
FEETECH FT90R 135 21 108 18 9  22.9 × 12.1 × 26.5  CW→CCW yes $8.95
FEETECH FS90R 130 21 100 18 9  22.5 × 12.1 × 23.4  CW→CCW $5.95

Products in category “Continuous Rotation Servos”

Pololu item #: 1248
Brand: SpringRC
Out of stock.
Quantity:

The SM-S4303R is a standard-sized servo that has been built by SpringRC specifically for continuous rotation, making it an easy way to get your robot moving. It features two ball bearings on the output shaft for reduced friction, and it offers easy access to the rest-point adjustment potentiometer.

Key specs at 6 V: 54 RPM (no-load), 71 oz-in (5.1 kg-cm), 41 g, CCW rotation for pulse widths above the rest point.

Pololu item #: 3448
Brand: SpringRC supply outlook
Out of stock.
Quantity:

These are surplus SM-S4303R standard-sized servos continuous rotation servos that we are able to offer at specially discounted pricing. They are functionally identical to our stock SM-S4303R servos except for the direction of rotation, which is reversed, and we are selling them in pairs to help differentiate them. This product is a two-pack of servos, so ordering one unit will get you two servos.

Key specs at 6 V: 54 RPM (no-load), 71 oz-in (5.1 kg-cm), 41 g, CW rotation for pulse widths above the rest point.

Pololu item #: 3430
Brand: FEETECH
RoHS 3 compliant
Out of stock.
Quantity:

The FS5106R is a standard-sized servo that has been built by FEETECH specifically for continuous rotation, making it an easy way to get your robot moving. It features two ball bearings on the output shaft for reduced friction, and it offers easy access to the rest-point adjustment potentiometer. This servo can work with both 5 V and 3.3 V servo signals.

Key specs at 6 V: 95 RPM (no-load), 83 oz-in (6 kg-cm), 40 g, CCW rotation for pulse widths above the rest point.

Pololu item #: 3432
Brand: Parallax
RoHS 3 compliant
Out of stock.
Quantity:

The Parallax Feedback 360° provides the functionality of a light-duty standard servo, a continuous rotation servo, a high-speed servo, and encoder feedback in one convenient package. Its speed is controlled with standard RC servo pulses, just like a typical continuous rotation servo, and it provides a return signal line from an internal Hall effect sensor that provides digital angular position feedback. An external microcontroller can use this signal to make the servo hold any angle, much like a standard servo except without any limits on the range of motion, or it can use it for closed-loop speed control. Recommended operating voltage range is 5.8 V to 8.4 V

Key specs at 6 V: 140 RPM (no-load), 35 oz-in (2.5 kg-cm), 41 g, CCW rotation for pulse widths above the rest point.

Pololu item #: 2820
Brand: FEETECH
RoHS 3 compliant
Out of stock.
Quantity:

The FS90R is a micro servo that has been built by FEETECH specifically for continuous rotation, offering an inexpensive and easy way to get your small turret spinning or miniature robot moving, especially when paired with our 60×8mm wheels designed specifically for this servo. This servo can work with both 5 V and 3.3 V servo signals.

Key specs at 6 V: 130 RPM (no-load), 21 oz-in (1.5 kg-cm), 9 g, CCW rotation for pulse widths above the rest point.

Pololu item #: 2817
Brand: FEETECH
RoHS 3 compliant
Out of stock.
Quantity:

The FT90R is a digital micro servo that has been built by FEETECH specifically for continuous rotation, offering an inexpensive and easy way to get your small turret spinning or miniature robot moving, especially when paired with our 60×8mm wheels designed specifically for this servo. This servo can work with both 5 V and 3.3 V servo signals.

Key specs at 6 V: 135 RPM (no-load), 21 oz-in (1.5 kg-cm), 9 g, CCW rotation for pulse widths above the rest point.

Related Categories

RC Servos
Pololu Wheels for Servos
RC Servo Controllers
Servo Cables
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