The purpose of tip calibration is to calculate the distance from the second joint's center point (the A joint’s center) to the star probe’s tip center. You may want to measure more than one AB combination so that PC-DMIS can average the star tip offsets computed, resulting in better accuracy in reaching the sphere when the CJoint calibration cycle is performed.
Before proceeding, verify the following:
You should already have calibrated the AB wrist device; and the files named acomp(s).dat and wrist(m)(s).dat should exist on your computer’s hard drive.
You need to mount a star probe on the CJoint device with the tip pointing in the X+ direction. PC-DMIS uses this tip to calibrate the CJoint. Tip calibration in this case does need to be done.
You can also obtain the AB calibration map with the CJoint mounted on the wrist. This increases the accuracy of angle position computations for any A, B, and C angle combinations.