Servo Encoders vs Steppers

> I can see that any motor with an encoder would offer much higher
> positional accuracy, but since there are so many machines without it,
> I don't think it matters for many of them.

Actually, there's a limit to positional error there also. Servos have a
dead band in which they won't move even if the table moves. One of the
settings of a servo amplifier has to do with setting that dead band. If
you set it too large, you can have large positional errors. If you set
it too small, the servo will continually hunt back and forward (CW and
CCW motion) looking for the deadband.

-- Jerry Jankura
Strongsville, Ohio
So many toys.... So little time....