Re: Caliper scales

Thank you for the research - this would be an excellent way to get a
cheap DRO for a mill or lathe!

Thank you again!

Brian Collier

--- In CAD_CAM_EDM_DRO@egroups.com, Ron Ginger <ginger@a...> wrote:
> I found the article- PROJECTS IN METAL, August 1993- Vol 6 No4. page
> 17-25
>
> The title is 'DROS under $125 per axis' by Gene Martin.
>
> My memory was not very good!
>
> The pattern is actualy solid copper, with rectangular frames cut
out.
> The rectangles are 0.104 wide by 0.404 tall outside, and 0.096w by
0.396
> high inside the frame- that is the frame width is 0.008". The pitch
> between rectangles is 0.200
>
> He made the part by coating the PC board with resist, then scribing
the
> frames through the resist. The board was then etched, making the
frames.
>
> The article describes a spring loaded scriber he put in the mill,
with a
> point havnig a .006 to .008 round tip. He shows a rather clever
holder
> with a spring behind the scriber.
>
> The article also lists a Gcode routine that cuts a 28" long scale.
He
> also details a set of aluminum blocks miled out to mount the encoder
> head.
>
> I have a Mitutoyo DRO -the ~$700 one, that uses scales that are
also PC
> boards, but they are rectangles of copper on a clear field, not
frames
> like this article. So I re-state the suggestion I made eariler- if
you
> want to do this you better buy the calipers you plan to use first,
and
> take their scale apart and measure it, it may well be different.
>
>
> ron