Quote Originally Posted by Tenson View Post
Sorry to keep this off topic from the sale, but what is the difference between a servo motor and this? Servo really just means a feedback loop which is what the optical encoder provides. Also is the smoothness Jazz mentioned not simply to do with the motor? I wouldn't think the encoder will be responsible for that.
The term 'servo motor' is generally used for DC or brushless DC motors, which tend to have a low pole count compared to a stepper motor, so they are quite different in that respect, however the control systems are similar. The 'smoothness' is greatly dependent on the resolution of the encoder, which is where 'genuine' servo motors are likely to be better since good ones come with much higher resolution encoders - 16-bit and 20-bit are common, compared to only 10-bit (1000ppr) on the stepper motor linked to. To put it simply, with a higher resolution encoder the controller is getting more information about the motor, so is able to compensate for errors, and smaller positional errors.