Re: Timing Pulley Accruacy and Servo shaft runout

Hi Les,
Yes the one that measured .005 at the end of the shaft was a
new motor and appeared undamaged. But it was by far the worse
one. The other motors measured in the .002 range. Still more
than I expected.
When you say anything below .0005" should be fine, did you mean
anything below .005"??
.0005" is on the otherside of the spectrum and a very small
runout for a timing pulley. I would have to both turn the motor
shafts and bore the pulleys to keep that.

If I did the math right, using the runout of .005" with the
motor pulley being 1" approx dia., I get an error of almost
.008". This almost sounds like too much error for that runout.

(.005/(3.14*1))*5 = approx .008

Thanks,
Scott

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Les Newell <lesnewell@...> wrote:
>
> Hi Scott,
>
> 0.005" sounds like a lot. To work out what effect it will have you need
> to know the diameter of the driven pulley.
>
> error = (runout / (3.14 * diameter)) * screw pitch
>
> You will probably find the result is extremely small. Unless you have
> some really top end hardware in a temperature controlled environment,
> anything below 0.0005" is probably fine.
>
> Les
>
> > Can anyone quantify the effect that .005" runout would have
> > on the accuracy in a mill setting?
> > What kind of accuracy should I be shooting for as a minimum?
> >
> > Thank You,
> > Scott
> >
> >
> >
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