Re: Timing Pulley Accruacy and Servo shaft runout

Hello,

Yes, you've got it.

There is also the possibility that the tightening and loosening
Effect will Affect the system in subtle ways. Not likely a problem
in this case, but in optical and semicondctor fab stuff like this
DOES matter... (The load is changing cyclicly, and therefore a
stepper or servo is not "following" as well as it could/should.

Now I'm going to disagree with an original reply here; which said
you did not want to try to compensate for your shaft runout with the
pulley--by turning it upon the shaft before locking it down.

It is a VERY good idea to do such things when you can. Tolerances
are tolerances, and they DO stack up. If you can adjust some part of
that stackup to reduce its overall value, it's a good thing.

Ballendo

>In CCED, "Polaraligned" <polaraligned@...> wrote:
>I do not really understand how an eccentric shaft will cause error.
>I see it as the belt just getting a bit tighter, and a bit looser
>as the pulley goes around.<snip>
>Now I think I understand: The pulley is seen as being a larger dia
>when the error moves the motor pulley away from the opposite
>pulley, and as a smaller diameter when the motor pulley is closer
>to the opposite pulley. Correct me if I am wrong.