How would one calculate pitch diameter for external threads on a CMM and verify that the results are correct. I need to check some pretty large acme threads im not too sure about the nominal dimensions.
I just did a test on a 2mm cylinder stylus yesterday.
Calibrated the tip using 5 shank points 5mm up the shank.
Then I measured the calibraiton sphere as a sphere and zero XY&Z axis to it.
Then I measured an autofeature circle at zero and dimension the diameter and a true position.
Diameter was within -0.0004mm TP was 0.001mm.
Next autofeature circle at -1mm
Diameter +0.0004 TP 0.0114
Next autofeature circle at -2mm
Diameter +0.0012 TP 0.0234
Next autofeature circle at -3mm
Diameter +0.0022 TP 0.0357
Next autofeature circle at -4mm
Diameter +0.0028 TP 0.0478
Mind you the next stylus build could be completely different.
I just did a test on a 2mm cylinder stylus yesterday.
Calibrated the tip using 5 shank points 5mm up the shank.
Then I measured the calibraiton sphere as a sphere and zero XY&Z axis to it.
Then I measured an autofeature circle at zero and dimension the diameter and a true position.
Diameter was within -0.0004mm TP was 0.001mm.
Next autofeature circle at -1mm
Diameter +0.0004 TP 0.0114
Next autofeature circle at -2mm
Diameter +0.0012 TP 0.0234
Next autofeature circle at -3mm
Diameter +0.0022 TP 0.0357
Next autofeature circle at -4mm
Diameter +0.0028 TP 0.0478
Mind you the next stylus build could be completely different.
