@droftarts Thanks for your help Ian,
Yes I manually turn on my router. I've added the M563 lines as suggested (makes sense now, and I realize I had a ;tools section in my config.g just commented out and not defined).
Now when I run the macro it moves to the bit to touch the side of the cavity in the X direction then then the Y direction but sometimes fails, i think depending on the starting location of the 5mm bit in the 15mm hole. I then get "error:G0/G1: target position out of machine limits" Is this due to the G0 Z15 line in the macro? if I enter this at the command line it sends the bit down into the stock.
I've looked at the wikki for configuring CNC machines, would be great if it had a section on setting up touch probes. I tried to start with using a G38.2 to set my Z zero but couldn't figure it out. My method was to enter G38,2 Z F100 and I assumed the spindle/bit would descend until the bit and plate made contact. Instead the bit descends a couple of mm and stops, am I missing something here?