SpringRC SM-S4303R Continuous Rotation Servo

The SpringRC SM-S4303R is a standard-sized servo for continuous rotation up to 70 RPM at 6 V. It is a strong continuous rotation servo with a specification of 4.8 kg-cm/67 oz-in at 6 V. Two ball bearings are featured on the output shaft for reduced friction, and it offers easy access to the rest-point adjustment potentiometer. The servo can be controlled using a direct connection to a single microcontroller I/O line without any additional electronics, which makes it a great actuator for beginner robotics projects.

This continuous rotation servo works by converting standard RC servo position pulses into continuous rotation speed. The default rest point or neutral position is 1.5 ms, but this can be adjusted by using a small slotted screwdriver to turn the middle-point positioner. Pulse widths greater than 1.5ms will result in counterclockwise rotation, with speed increasing as the pulse width increases; pulse widths below 1.5ms result in clockwise rotation, with speed increasing as the pulse width decreases. Note that this is the reverse of what is described in the datasheet.

The servo has a 270 mm lead that is terminated with a JR-style connector and comes with the included hardware as shown in images.

This robotics servo is compatible with Futaba-compatible servo wheels.

SM-S4303R datasheet (635k pdf)