OK I will review that .

Are you sure you are not seeing error from the probe trip itself. Lower end 3point pivot probes CAN be inaccurate when moving in certain directions such as not in line with a pivot ball. They are 3 point most accurate and 3 points worse accurate. It between it can vary as well.

** The probe is not being used at this moment, Just trying to find the source of the erroneous error**

Also are you sure it is not a step resolution problem where it cannot get to the position because of step resolution. It will add the remainder of the lost step value into the next move.

** You will see that the only step I use in the program is the actual resolution and multiples of it in the Wizard**

Just a thought, (;-) TP

The background for this was that I was probing a ground internal Diameter to get ready for a cut and I noticed a discrepancy in the numbers coming back on the dro's.

At first i thought there was contamination on the probe tip or job surface causing loss of electrical continuity. I eliminated this, then went on to Backlash, Steps per Axis etc etc. Eventually all that was left was an error in the actual program. In the MDI I couldn't find it, so I went back to the Wizard and that's were I found the error occurring.

Hence this Forum Discussion. I believe the error is specifically the G31 command has problems with large decimal place numbers and is truncating them using some method. Or it is simply missing the first microstep/step, either way there is an error in the G31 coding or my installation of Mach3. The issue doesn't raise its head unless you have large decimal place numbers, so 0.0125 or 0.0250 etc will work but 0.00208333333 or

**odd** multiples of this don't. These are actual step values I use so im really baffled as they are "all" multiples of the smallest step value

Wes