Re: Learning BDI Emc - Outputs

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

HI,

Ray, I think the clue is in the original question - our friend is wanting to
site his home switch near the centre of the axes travel distance which I
think is a no-no with EMC. With the switch at mid distance it will not be
possible to preset a homing direction as this will depend on which side of
the switch the travelling part is. The only way to get the machine to 'home'
to the centre of its travel would be to site the home switch at one end of
the travel and set the 'home offset' to half the travel distance so that the
carriage runs right to one end of the machine and then returns to the half
way point. Unless the machine is to be used purely for engraving on circular
disks or something similar, I cannot see the purpose of homing to the centre
and I would favour putting the home switches on the left hand end of the
x-axis and the back of the y-axis so that the cutter finishes up hovering
over the 'bottom left-hand corner' of a workpiece fixed to the table.

Ian
--
Ian W. Wright
Sheffield  UK
www.iw63.freeserve.co.uk
----- Original Message -----
From: "Ray" <rehenry-at-up.net>
> >  How does EMC know which way to travel to look for home.  Or
> > would it be better to locate it near one end of travel and offset
> > home to somewhere near the center.  That way one could always be
> > fairly certain of not going in the wrong direction because the table
> > would usually be away from an end.
>
> The first thing you need to do is set the input and output scale positive
or