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. We got them through a one-time purchase of surplus new inventory, and we do not expect to restock them once they are sold out. This product is a two-pack of servos, so ordering one unit will get you two servos.

These servos have been built by SpringRC specifically for continuous rotation. At 6 V, they have a maximum rotation speed of 54 RPM (no-load) and can each produce up to 71 oz-in (5.1 kg-cm) of torque. They each feature two ball bearings on the output shaft for reduced friction, and they offer easy access to their rest-point adjustment potentiometers. They can be controlled using a direct connection to a single microcontroller I/O line without any additional electronics, which makes them great actuators for beginner robotics projects.

The SM-S4303R continuous rotation servo converts standard RC servo position pulses into continuous rotation speed. The default rest point is 1.5 ms, but this can be adjusted by using a small screwdriver to turn the middle-point positioner. Pulse widths above the rest point result in clockwise rotation, with speed increasing as the pulse width increases; pulse widths below the rest point result in counterclockwise rotation, with speed increasing as the pulse width decreases.

Specifications:

• Digital?: N
• Speed @ 6V: 54 rpm
• Stall torque @ 6V: 71 oz·in
• Speed @ 4.8V: 43 rpm
• Stall torque @ 4.8V: 46 oz·in
• Hardware included?: Y
• Lead length: 11 in

Package Includes:

• 1 x Pololu 3448 Surplus SpringRC SM-S4303R Continuous Rotation Servo Pair (Two Servos)