We have recently started to replace our ruby tip probes with silicon nitride tips. However, we haven't been able to use any of them because we keep getting the "probe calibration exceed limit" error. All of our ruby tips calibrate fine. Has anyone else ran into this issue? Any trouble shooting ideas? I've done everything I can think of.
Some vendors define distance from the probe shoulder to the ruby differently. Unfortunately Hexagon shrank its probe inventory so bad our QC team had to source probes elsewhere with predictable issues regarding probe lengths. We have probes from Hexagon, itp, Q-Mark & Renishaw!
Another issue is what kind of probe module you have. Is it a scanning or touch probe? Because I ran into a problem where I would attach 1mmx20mm Renishaw probe to the Renishaw extended force module & it would not pass calibration standard deviation. By attaching it to the low force module it passed standard deviation with no difficulty.
Yet another issue might be calibration touchspeeds. For probes less than 2mm in diameter we set the touchspeed at 1% (we work with percentages).
Some vendors define distance from the probe shoulder to the ruby differently. Unfortunately Hexagon shrank its probe inventory so bad our QC team had to source probes elsewhere with predictable issues regarding probe lengths. We have probes from Hexagon, itp, Q-Mark & Renishaw!
Another issue is what kind of probe module you have. Is it a scanning or touch probe? Because I ran into a problem where I would attach 1mmx20mm Renishaw probe to the Renishaw extended force module & it would not pass calibration standard deviation. By attaching it to the low force module it passed standard deviation with no difficulty.
Yet another issue might be calibration touchspeeds. For probes less than 2mm in diameter we set the touchspeed at 1% (we work with percentages).
We don't have the ability to change to a low force module. We are working with an HH-MI so the tips just twist in. I changed the touch speed from 2 to .5 and it still failed. its possible that the distance from shoulder to tp is defined differently. still waiting to hear back from Reinshaw.
it will correct the length after the first calibration, even if it fails. The length might not be perfect in the results (yet), but a 3rd calibration will correct for any length different less than 2x the ball size.
SO, STDDEV tol is set to 0.0003937" and the size tol is set to 0.0006". Is this correct? And you are using a TTP (touch trigger probe)? 0.0006" is too small for the size tolerances. IMO the STDDEV is too high. STDDEV of 0.0002" is plenty big (half of what you are using). AND, the size tol is way too small. The calibrated SIZE will always be small on a TTP. For that 1mm ball on a 27mm long probe, you are going to be 'REALLY' small due to the flex of the shank. I would expect to see it small by 0.010" or so. The STDDEV is the critical result. You need to calibrate then check a known 'standard' (ring gage, micrometer standard, etc.) and see what your results are.
