Re: EMC Homing Switches

[Dan Falck <dfalck-at-sprynet.com>]

On Sat, 22 Jul 2000, you wrote:
> Ok I'm finally getting around to putting homing switches on my machine.
> Problem is
> the EMC web site shows only pin 12 for homing all 3 axis'. If 3 switches
> are all
> connected to pin 12 in parallel, and I home the X axis, how do I then
> home the
> other two axis'? Do I need to add a 3 position switch to connect proper
> switch
> to the homing input when I'm ready to home that axis?
> 
> Thanks, Bill
> scalione-at-netarrant.net

I always have to home one axis at a time.  It's a real pain and makes it kind
of slow.  You have to trip one and then back off.  Then do the next axis.  
With an old program called "Dancam" one could home all three in sequence -
without having to back off the last one.  It would also run across the switch
several times -running past the switch in smaller increments with each pass (
and also slowing down with each subsequent pass).  I can't remember exactly how
it was hooked to the parallel port, but it was still pretty simple.

As a side note, I had to work on a Komo router this last week.  The machine had
lost it's home position and the operator couldn't get it back in sync.  I found
that the machine used a prox switch to get course home position, and then
relied on the one revolution mark on the motor encoder to find the exact home. 
It would run past the prox switch, then slow down until it hit the one rev
mark.  We ended up having to turn the power off to the machine, move the table
via the ballscrew by hand to the absolute home postition (thank god it had
pnuematic locks that lock in place at home) and then turn the power back on.  

Dan