Re: optical encoders

Jon,
I think the label on the motor says 200 Pulse Per Revolution and
not Cycles Per Rev (CPR) of the encoder. I guess I have to see the
specs on this motor to find out how man cycles/rev the motor itself
can have. I am new to CNC and still need to learn things.

Thanks,

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
> george_barr wrote:
>
> >I have stepper motors with 200 pulses per revolution (ppr)
encoders
> >on them. I would like to upgrade the disc on the encoders to get
> >higher resolutions on them. Does anyone know how high of
resolution
> >or PPR I can go? How much are the discs? Any advice?
> >
> >
> What is the purpose of putting high resolution encoders on low
> resolution motors?
> Do you really think this will increase the resolution of the
system?
> Just because you
> have X100 microstepping drives, do you think the motors can be
> positioned in such
> tiny fractions of a step? You can pretty much rely on getting half
> steps, and probably
> quarter steps, but friction interferes with getting much finer
motion
> than that.
> I suspect you will end up with lots of hunting, but no real
improvement in
> actual positioning if you do this. If the current encoders are 200
> cycle/rev, you
> get 800 counts/rev if you count all transitions. I dislike
pulses/rev
> as it has an
> imprecise meaning.
>
> Jon