Re: need axis design idea

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Elliot Burke" <elliot@...>
wrote:

>

<SNIP>

> Another plan might be to have a PC board made with the pattern for

a digital

> caliper on it; the pattern could be repeated a lot of times across

the width

> of the board, then cut up into strips and assembled end to end to

make a

> long travel. If this works I'll report back here.
>
> The mill scales made like that aren't long enough for my project.

I wonder

> if the scales are limited in how far they'll read?
> The external readout boxes for them might read the internal

values, and so

> would have the same limit in travel.
>
> regards-
> Elliot
> --

Scott Shumate has a very definitive writeup of the Chinese scale
protocol on his website ( www.shumatech.com ). They function as
absolute encoders as the transmitted value is the current position
instead of an incremental change like you get from a quadrature
encoder. I recently exchanged an 8" caliper that was trying to
convince me that it was 45" long (straight out of the box), so the
limits are on up there a ways. Based on that, I'd say that the idea
is well worth a try.

Cheers,

Travis