Re: Re: Learning BDI Emc - Outputs

[Ray <rehenry-at-up.net>]

Ian

I've no doubt but that intuitive logic is on your side.  It would be possible 
however to center the switch and apply a home offset that shifts the axis in 
the opposite direction to that taken when the home sequence is initiated.  
Then you have only to be certain that you home out the machine each time 
before shutting it down.  Of course it would also be wise to look before you 
press the home siwtch and to be ready to press abort.

Ray 


On Wednesday 09 January 2002 03:52 pm, Ian wrote:
> 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