home switches

Hi

I'm a bit confused about the whole concept of home switches. How do
you get any degree of accuracy and repeatablity based on mechanical
contact of a switch closing? What sort of things have people done
for this? Just wondering because I'm at the stage in my micro mill
CNC project where all I have remaining is wiring up the
home/limit/stop switches. The stop switch was easy - just connected
the switch to the output-enable pins of the allegro-micro 5804 (maybe
some pull-up resistors were used to, I forget exactly). I am using
EMC on linux.

cnc project page http://www.margrave.com/static/cnc/

Dave