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.
Test on Global Advantage with an SP600
Yep, the shank calibration is a half-made, half-finished, botched job of programming. What use is there is a shank calibration when you can not tell Pcdmis to USE that info? ALL data comes from the center of the ball, NONE comes from the shank of the probe. Absolutly useless addition to the software that too many people think means "something"....
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.
Test on Global Advantage with an SP600
Yep, the shank calibration is a half-made, half-finished, botched job of programming. What use is there is a shank calibration when you can not tell Pcdmis to USE that info? ALL data comes from the center of the ball, NONE comes from the shank of the probe. Absolutly useless addition to the software that too many people think means "something"....
