CNC solder paster dispenser - how do I approach this.

[HankMcSpank]

Ok didn't realise that.! . . . If theres something to probe against then It's very easy to find the centre of a square or circle.

There's no need to auto probe to get the cnc machine to find the SMD pad centre , my pcb software can either give me those coordinates or I can export the smd pad as a gerber file & import into a cad program & get the cad software to mark the centres of each SMD pad. (which I can then use cam software to use this coords with)

Ok so using this brain melarkey....my z plane lowers & once at say 0.2mm, a trigger happens....but what is the output here? Mach 3 has control of the printer port, presumably once the 0.2mm threshold is breached a nominated pin will change state?