M31 tool length help...

[krsykes23]

I'm asking for help with simple Tool Length probing. I'm using the M31 macro supplied with UCCNC, as I cannot figure out the Probe facility and all I need to do is measure the length of the tool. I did change the supplied M31 macro, from G44 to G43.

I have a fixed tool length probe/sensor positioned at X98.2 and Y1.8. It triggers at exactly 7.0 in Z (LOWER) from the height of the spoilboard. On my previous Mach3 setup, I would run the M31 Tool Length macro if I changed a cutter or skimmed the spoilboard. Obviously, after skimming the spoilboard, I would adjust the difference in Z to the exact trigger point of the sensor.

The macro works as it should, by moving to the X and Y coordinates of the sensor and it probes twice. I have a field (169 Tool Offset Z) on the screenset and after running the M31, this field updates to 8.0. I'm puzzled as to where is this figure 8.0 coming from? I ran three tools with the M31, all of which are different lengths, so I was expecting different values to be updated in the Tool Offset Z field but the field always returns a value of 8.0.

I appreciate that I haven't yet set the spoilboard to sensor trigger point in the macro (as I don't know how or where to add this!) but if could someone can assist me with this, I'd be grateful. Thanks.