Hi,
  I am having a look at making a auto tool changer along the lines
of the simple Router type i.e. the head moves to a number of places on the
table where tools are located and picks them up.
I really need the coordinates for this process to be done in the machine coord system.
otherwise its a bit of a nightmare setting up.
 How can i change the machine to work in these coord.s during my tool change,
and then come back out to fixture coordinates to machine?
    Tony

If you use G53 these are absolute machine coordinanates relative to the zero return position.

e.g. G53 x-5. y-5. z-5.

And this is your standard work offset

G54 x0 y0 z0

Graham.

Remember to make sure you REF home the machine when you first fire it up to set the machine coordinate base the same each time. (;-) TP