Tip calibration assumes that you have already calibrated the wrist. It does not need to be done for the tip that is used to calibrate the wrist. Tip calibration is done automatically for the tip used to calibrate the wrist.
The purpose of tip calibration is to calculate the distance from the last joint's center point (A joint) to the tip center. Theoretically, measuring one tip AB combination is sufficient for PC-DMIS to compute this distance once the wrist is calibrated. However, to get better accuracy, it's a good idea to measure more than one AB combination so that PC-DMIS can average the computed tip offsets.
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