Re: Make your own linear scales

Jon,

What is your "gut" feeling about a homeshop guy or gal creating glass
scales like this? Could we do the etching necessary?

What other options do we have for creating our own linear scales?
(Besides cable/encoder)

I've always thought the "spherosyn" could be "home-shop-able"
(precision ball bearings in a tube, read capacitively sin/cos)

Also have thought about the old "wire" tape recorders...
What about recording a sine wave (signal generator created), and
reading it with a std. recorder head. Then looking for a way to have
TRUE metal tape. Iron oxide?

Thank you in advance.

Ballendo

Jon Elson wrote:

> Well, with 2460 pixels/inch, you could write every other pixel,
> and get 1230 cycles/inch. With a quadrature read head, that would
> give you 4920 counts/inch, or .0002" resolution (actually,
> .00020325")
>
> This sounds like what the standard commercial linear scale
> does. Of course, this would be a plastic scale, unless you
> printed the master onto a glass plate coated with tungsten
> or similar metal, and then etched it through a resist.
>
> Jon