RE: Re: Great deals on encoders

I got out of doing the math just by calling US Digital. The tech person
(sorry wish I had written his name down) was very helpful and even looked up
the exact specs and called me back with the answer. I am impressed.

I think I will go ahead and have some films made at a local service bureau
with 184 LPI just to see if it works. If that turns out to work with my
encoders I would be happy to do up a sheet with whatever is appropriate for
the encoders that go to the 2048 CPR for testing purposes if someone that
has one of these encoders would try it out. I don't think the films will
have the required accuracy to use for the linear encoder strips, but I think
they will be good enough for proof of concept before someone shells out $200
in tooling costs on something that we are not sure will work.


Tim
[Denver, CO]

> -----Original Message-----
> From: Tom Kulaga [mailto:tkulaga@...]
> Sent: Wednesday, July 14, 1999 10:01 PM
> To: CAD_CAM_EDM_DRO@onelist.com
> Subject: [CAD_CAM_EDM_DRO] Re: Great deals on encoders
>
>
> From: Tom Kulaga <tkulaga@...>
>
> > From: "Tim Goldstein" <timg@...>
> >
> >I just talked with the tech people at US Digital and the answer
> appears to
> >be that by design and specification it will not work, but they have never
> >tried it and think that if the correct LPI strip was used it may be
> >functional. His calculations are that it would use a strip with
> 183.8 +- 10%
> >LPI. So the best resolution would only be about .0015
> >
> >Based upon the +-10% he thinks the stock 200 LPI strip may work.
>
> Using the same logic, what would happen if we took the HEDS units
> that are for the 2048 CPR encoder disks, and had USD make up linear
> strips to match? I haven't taken the time to sit down and do the
> math to determine the required linear spacing to work with an 11mm
> codewheel, but I'm guessing it's pretty small. If the resulting
> quadrature output gets us past the magical .0005 resolution, I'd be
> willing to kick in cash to pay for USD's tooling costs (about $200
> IIRC).
>
> -Tom Kulaga