Re: [CAD_CAM_EDM_DRO] PIC DRO

james owens wrote:

> I beg to differ as I have the said item at $22.00 which I bought one
> off. The invoice is dated 11.15.1999 and I am quite happy to send you
> a copy.
>
> Check out the site at usdigital.com the prices they publish on the
> site are what they bill. I have nothing to do with the company, just
> found them very easy to deal with. As you know Jon I am resident in
> England, UK.
> ----- Original Message -----
> From: Jon Elson
> To: CAD_CAM_EDM_DRO@egroups.com
> Sent: Wednesday, April 05, 2000 9:08 PM
> Subject: Re: [CAD_CAM_EDM_DRO] PIC DRO
>
>
>
>
> jguenthe wrote:
>
> > And the part number is?
> >
> > Regards
> > John
> >
> > -----Original Message-----
> > From: james owens [mailto:wotisname@...]
> > Sent: Wednesday, April 05, 2000 2:41 PM
> > To: CAD_CAM_EDM_DRO@egroups.com
> > Subject: Re: [CAD_CAM_EDM_DRO] PIC DRO
> >
> > I have in my hand an encoder from USDigital with a 5/8" bore 2000
> > lines per
> > rev with index $22.00
>
> You may rest assured, the catalog price of this item is WAY higher
> than
> $22.
>

Wait a minute, is this 2000 LINES/REV or 2000 COUNTS/REV ? There's a
big difference, a factor of 4! The 2000 count/rev encoder is actually
500 lines/rev,
and decoding all transitions. A 2000 Line/Rev encoder would produce
8000
quadrature counts/rev.

I was thinking of one of the BEI, DRC or such, commercial hermetic or
semi-hermetic
encoders, with index channel. I'm guessing that the one you have is
really a 500 line/rev,
non-sealed, plastic-case (or even open) encoder without the index
channel, and
it has a plastic encoder disc. Do you have any specs for the cyclical
error on the
encoder disc?

You can get 1000 line/rev encoders in 2 pieces from HP. The disc
(metal) is
one piece, the read head is another piece. So, you have to make your
own
housing. You would get 4000 counts/rev from these. They DO cost more
than
the US Digital units, but are probably higher quality.

Thanks,

Jon