Re: Re: Cheap Encoders

> From: mike grady <mgrady@...>
>
> I have been thinking about doing this
> and using small prec, timing belts
> mike
> Matt Shaver wrote:
>
> > > Yes it has been done before. Steve Stallings had a good idea using a wire
> > > set up like a radio dial connected to a encoder. The mechanical part worked
> > > fine but there were problems finds a pc lpt card that would work well. The
> > > linear encoders are much simpler and more positve.

Be warned that the pitch of the belts is certainly not as accurate as a dial
caliper, for instance, and the belt sprockets are not always centered very well.
I got some sprockets from W.M. Berg, and had to do some fancy work,
because the hole was over .010" off center with respect to the OD.
This would have caused some serious cyclical errors in a DRO system
(or servo).

Jon