Re: Manual Control

If you're interested in a homebrew shaft encoder, I would suggest
reading http://www.dprg.org/projects/2001-09a/. I built one of these
and have been using it for a year with no problem. However, since you
are using hand cranks you might have to worry about jitter when you're
on the edge of a light/dark band. I tried programming my own with a
microcontroller and it's a pain in the *#!. I've beat my head against
a wall playing with this.
What I ended up doing was combine the Hamamatsu photoreflector with a
"quadrature decoder" chip. A little 8 pin dip package chip. Just do a
search on google for it. I'm sure you'll come up with a decent
solution. The output will be two signals - a direction and a pulse to
measure speed. I'm at work so I can't find out what chip it was that I
used. These two in combination should give you rock-solid results. If
you have any more questions, give me a shout.

Regards,
Derek

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "roboticscnc" <gsm42@o...> wrote:
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "James Peck" <jamesgpeck@y...>
> wrote:
> >
> > I can give you a schematic for wiring a remote Handwheel to an encdac
> > card used with OpenCNC.
> >
> > -----Original Message-----
> > From: CAD_CAM_EDM_DRO@yahoogroups.com
> > [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of roboticscnc
> > Sent: Friday, December 16, 2005 7:49 AM
> > To: CAD_CAM_EDM_DRO@yahoogroups.com
> > Subject: [CAD_CAM_EDM_DRO] Manual Control
> >
> > Hi guys. My lathe retrofit is almost complete but I would like the
> > option of manually controlling the servos using an input from encoders
> > mounted on handwheels. Does anyone have wiring information to set up
> > this function ? Thanks, Glen.
> >
> >
> >
> >
> >
> >
> > Thanks James, a schematic is exactly what I'm after. What I had in
> mind was somehow converting the quad signal from the encoders to a
> step / direction signal ( using a switch to select either manual or
> cnc control ). Maybe there is a simple circuit to do this. This way
> the computer doesn't have to be switched on. Any information anyone
> can send me would be greatly appreciated.
> Thanks, Glen.
>