Originally Posted by
dharmic
1. Connect a bit of wire from one of the GND terminals and a bare end you can tap on the screws of the IN terminals to work out what's what.
2. In Mach3 under the Config menu, select Ports and Pins.
3. Go to the Inputs tab.
4. Set up the Probe input. Enable it and set the right pin number. Which one it is will depend on the board. If you can't get find that out, it's an input - no harm in just going up the numbers one by one until you find it. Skip any input pin numbers that are already used by other enabled inputs because you know it ain't them. If the first three inputs are used by homing switches on your machine, you'll probably be able to work out the next number in the sequence and use the 4th pin and its ID.
5. You can verify good connection by going to the diagnostics page. Touching the wire to the IN terminal of choice should turn the digitize indicator ON and removing it should turn it off. If it's the other way around, check the inverted box on the PROBE input and try again.
6. Now you have your config setup.
7. Cut the alligator clip from the probe and strip both sides of the wire.
8. Get some twin core flex - thin speaker wire works fine. Attach the alligator clip to one wire and the other end of that wire goes into the GND terminal. Attach the probe wire to the other wire and run its other end into the IN terminal.
9. Verify that the DIGITIZE indicator is off on the diagnostics page.
10. Clip the alligator clip onto your tool bit. Touching it to the probe should turn the DIGITIZE indicator on.
11. Now you have your wiring!
To use (manually):
1. Accurately (micrometer?) measure the height of the tool probe.
2. Jog your tool roughly down to 3mm / 1/8" off the probe.
3. Set Z to zero on the main screen's DRO.
4. From the MDI window enter
G31F30Z-10
5. The tool should come down slowly and stop when it contacts the probe.
6. Back to the main screen, set Z on the DRO to the height of the probe.
7. Jog the tool up off the probe and unclip, remove the probe from the area.
Your Z in the current workspace is now set so that zero corresponds to the tool tip sitting on the surface upon which you were resting the tool.
Note - you can script this as a button script on the "auto tool zero" button on the front page. There are examples kicking around the net.
Hope this helps.