Re: These servo motors worth a darn?

batwings@... wrote:

> That should be the most accurate way to use them; connected
> directly to screws the only errors you'll get would be in screws
> themselves.

I'm not concerned with physical accuracy here. Surely having the encoder
directly attached to the screw is optimimum for accurate measurement of
what the screw is doing. What I am not sure of is if having the motor
and the encoder separated by a timing belt might introduce any sort of
servo error. If there is even the slightest wrapup or lag between the
belt and screw (most noticable when accelerating a heavy load from a
stop) will the controller see no motion for the given output and start
ramping in more current than really required. This is a big difference
between stepper and servo systems. The encoder tracks motor velocity as
well as position.

Jon