Re: EMC Homing Switches

["Ian Wright" <Ian-at-iw63.freeserve.co.uk>]

I'm still a bit confused here - are we saying that position 0,0,0 should not
be the same as 'home'? Its this clever thing of EMC making all the axes
arrive at the desired end point at the same time (which, of course, is
essential if it's to cut accurate angled lines and curves). If the machine
is commanded to 'go to 0,0,0', say at the end of a program as seems to be
fairly common, then the limits will be tripped but how will EMC know which
axis to then reverse to back it out to release the switch again? Also,
presumably, when one axis trips the home switch, the whole machine stops,
but what happens when that axis then backs out to it's 'home offset'
position - does the machine start up again to try to home the rest of the
axes. If so I would imagine that all you would get would be an oscillation
on the first axis to have homed as it repeatedly homed and then backed out.
I hadn't realised that this was a 'feature' of EMC and I would certainly
feel happier with separate switches for each axis even if that meant putting
them on the second port.

Ian

--
Ian W. Wright
Sheffield  UK


----- Original Message -----
From: William Scalione <scalione-at-netarrant.net>
> >
> > You are correct. about the nature of pin 12.  Only one switch connected
to
> > it can be activated at a time.   These switches are expected to be
> > wired in parallel if you are using normally open switches and in series
if
> > you are using normally closed.
> >
> > But the process of touching the switch and then moving the axis enough
to
> > reset that switch can be set up in the ini file.  It's HOME_OFFSET and I
> > set mine to 0.1000.
> >
> Ray
>
> OK, That makes sense. It didn't seem like I should have to home X, then
move
> X manually off of home in order to home Y or Z.
>