Re: gEDA-user: Universal Turin^H^H^H^H^Hmilling machine

[Karel Kulhavy <clock@twibright.com>]

On Sun, Nov 07, 2004 at 07:58:52PM -0500, Charles Lepple wrote:
> On Sun, 7 Nov 2004 15:14:29 +0000, Karel Kulhavy <clock@twibright.com> wrote:
> > And a Gray-code readout strip (graycode is simple - take a normal binary code
> > and derivate it from left), use it in feedback loop and you get unprecedented
> > performance - or not? :)
> 
> I'm going to hazard a guess that if you build an incremental encoder
> yourself (as the above description reads), you are probably going to
> sacrifice more accuracy than you would lose (due to backlash) by using
> a low-cost X-Y table and gearing down some brush motors. (Unless, of
> course, you can find excellent-quality encoder read heads from some
> surplus catalog.)

What abut exposing the codes on a sheet of document film, epoxying to a glass
plate and using linear CCD for readout?

Cl<
> 
> -- 
> - Charles Lepple