A number of years ago, I successfully made a Tool Height Sensor for a home made CNC. Having sold that one and have recently built a new 3 axis machine, I have forgotten how I did the first one.

It consisted a steel plate mounted on a light spring. This plate was connected to Pin 15 of Mach3. When the tool touched the plate, the sensor worked fined. It was a simple continuity function, not an electrical switch.

I now have a Kress spindle with an auto tool-changer. I cannot get a continuity system to function with the Kress and ATC. I purchased a switch type tool sensor but have been told that they can be unreliable?

Any ideas how I can get a continuity system to function?

Also, on the previous Tool,Sensor, I had a simple macro to operate the Tool Sensor. This consisted just a few lines of code, that when called for, moved the X and Y, then Z slowly over the sprung plate until continuity was made and Zero'd out.

Thanks. Keith