Touching on

[Clive S]

To make a touch off tool system you just need a small bit of pcb with a wire soldered to it and you then can make a simple circuit with a battery and led with a resistor in series with it. Then the -ve wire will connect to the machine frame and the led wire to the pcb. You need to know the exact thickness of the pcb, Just put the pcb on the top of the job and bring the z down very slowly until the led lights up.

Then Zero Z then add the thickness of the pcb to the zero and re zero. If all that make sense. >Clive

(Neil beat me to it)