Re: [CAD_CAM_EDM_DRO] Encoder on spindle question

On 7/26/2011 9:24 PM, David G. LeVine wrote:

>
> On 07/26/2011 02:32 PM, Ron Thompson wrote:
> > If I use the index, Mach never sees it. If I use either channel, the
> > index light (on the diagnostics page of Mach3 turn) will pulse slowly.
> >
> > The spindle speed dro stays at 0. Do I need to turn it on somewhere?
> >
> > I am guessing the pulse width is too narrow for mach to read. My
> > thoughts for a cure are to add a couple of decade counter chips to
> > divide by 40 or so.
> >
> > I'd like to use the existing encoder, but as a last resort I will remove
> > it and install a SB5B to give one pulse per rev.
> >
> > Thanks for any help!
>
> To find out if it is a pulse width problem, you may need to add a "one
> shot", but, as I understand it, Mach relies on 1 PulsePerTurn encoder
> operation for threading, otherwise there is no way to be sure that the
> thread starts in the same place.
>
> Adding a counter won't help, it will still not set the phase of the
> index pulse. Add a single pulse per turn encoder and it MAY work, but
> for it to work either the spindle must be a closed loop system (for
> constant speed) or be massive (so it doesn't change speed as the tool
> contacts the work.)
>
> Dave 8{)
>

Fixed. Sort of. I found that the pin I was using on the C-10 breakout
board was bad. I switched to pin 13 and it's working. I was able to use
any output of the encoder to send pulses to Mach3, but the numbers were
way too high. I then used the pulley setup as a programmable divider to
get the numbers in the ball park. There is still some jitter in the
readout. Maybe noise? I played with the debounce settings to no avail. I
really didn't think the encoder output would need debouncing, anyway.
Every time I try to use this breakout board, I have problems. I ordered
a straight breakout board to see if that makes a difference. I may need
to replace all the chips on this one.

Thanks for your help.

--


Ron Thompson
On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

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