Re: Trak cnc 2 control replacement

Gentlemen:

I believe Southwest Industries bought Trav-A-Dial which originally
was a mechanical "DRO". It used a wheel pressed against a smooth
plane surface on a machine. The wheel caused a dial type indicator to
turn as well as other geared-down counters so that the linear
position could be displayed. The wheel diameter was slightly oversize
and the axis angle was adjustable to the direction of motion
(normally 90 degrees)so that by tilting the axis slightly, exact
measurements could be obtained. It was a "neat" scheme promoted some
years ago. Likely the same idea could be used with a shaft encoder
being turned instead of a dial indicator.

Regards,
Jack C.
--- In CAD_CAM_EDM_DRO@yahoogroups.com, "seb fontana"
<speedoo51@y...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...>

wrote:

>
>
> Original post 69159
> > Jon reply>
> > Are you sure it has encoders on the motor AND on the axis? That
> presents
> > a "sensor fusion" problem - like the guy with two watches who
> wonders
> > what time it really is? I wonder if the motors have DC

tachometers

> instead.
> > That is a much more common arrangement.
> >
> > Using wheels to get position information from the table sounds
> pretty
> > strange.
> > A little dirt could cause it to skip or jump, and the absolute
> position