Need some basic information about servos? Check out our “What is a Servo?” page here:
Hope you are ready for some confusion… Um, I mean clarification.
Analog Standard Size Servos.
180° out of the box.
Responds to aprox: 500uS - 1500uS - 2500uS.
HS-422 - 57oz.in. - $12.99
HS-475HB - 76oz.in. - $17.99
HS-645MG - 133oz.in. - $39.99
Analog Standard Size Continuous Rotation Servo.
360° (non-positional)
Responds to aprox: 1300uS - 1500uS - 1700uS.
Stop Value = ~1500
Deadband = 20uS
Full CW = (Stop + 200uS)
Full CCW = (Stop - 200uS)
HSR-1425CR - 57oz.in. - $12.99
Digital Standard Size Servos.
Capable of ~140° out of the box. Can be programmed for 180° with the HFP-20 servo programmer.
Responds to 1100uS - 1500uS - 1900uS.
HS-5475HB - 76oz.in. - $34.99
HS-5645MG - 168oz.in. - $54.99
Digital Standard Size Robot Servos.
Capable of 180° out of the box, and the HMI Servo Programmer can alter the parameters.
Responds to: 600uS - 1500uS - 2400uS.
HSR-5980SG - 417oz.in. - $109.99
HSR-5990TG - 417oz.in. - $124.99
Digital Robonova Robot Servos.
Capable of 180° out of the box, and the HMI Servo Programmer can alter the parameters.
Responds to: 600uS - 1500uS - 2400uS.
HSR-8498HB - 103oz.in. - $59.95
HSR-5498SG - 188oz.in. - $69.99
thanks…
Sigh… yes the sentence above is accurately written to say the 645 responds to pulses in the range of aprox: 500uS - 1500uS - 2500uS. 
Additional info:
Anatomy of a Servo
Servos consist of four basic components: a motor, gear reduction, feedback device (typically a variable resistor potentiometer), and a control board. The motor, using a series of gears, turns the output shaft and the potentiometer simultaneously. The potentiometer is fed into the servo control circuit and when the control circuit detects that the position is correct, it stops the motor.
Centering
Speed and Torque
Types of servos:
How servos can be used:
Nice info. Where did you find all of it?
Alan KM6VV
its been on my system for a while now so im not sure were i got it from. i hope it is of use to anyone? 