Re: [CAD_CAM_EDM_DRO] Re: Stepper motors as encoders

"M. SHABBIR MOGHUL" wrote:

> Hi all
> i have dro box but not scales. it made from usa. how type encoder will be
> use for this??

It could be ANYTHING! Sony, Teledyne and Accurite (and many others) use
optical
scales. Farrand makes linear inductosyns used in some CNC machines and maybe
some are used in DROs. Newall makes a system based on precision steel balls
stuffed into a tube and sensed by an electromagnetic scheme that interpolates
the
basic quadrature signals from the balls. Someone else makes a
magnetostrictive
sensor that sends an acoustic wave down a steel tape inside a tube, and senses

when it hits a discontinuity caused by magnets in the totally passive read
head.
I guess they have to compensate for thermal effects in that one. Renishaw,
Heidenhain
and maybe others have magnetic tapes that have a pattern of fine magnetic
stripes
recorded on them. the advantage of these is that the tapes can be made VERY
long, up to tens of meters! There are probably other systems beyond this, as
well
as myriad pinouts, voltage levels, direct reading and interpolation schemes,
and so
on!

Jon