hexagon logo

Avoiding the Bottom of the Sphere during Calibration

Hi all-

I have had many calibration questions recently.

Here is the issue:

There are two machines, running the same exact probe and build. The only difference between the two calibration setups is that on the new one, we are using a calibration sphere that is at a 30 degree angle pointing towards the front of the machine. We have set the shank vector accurately so that PC-DMIS is aware of the direction the shank is approaching from.

The probe we are attempting to calibrate is an L probe. It is a 1x10 probe pointing towards the front of the machine on a 50+35mm extension. There is no problem calibrating the A0B0 angle for the probe, but when we get to the A0B180 side (front of the sphere), the probe goes too close to the bottom of the sphere and shanks out on the sphere. This is because PC-DMIS knows that it can take hits on the bottom in this orientation because the sphere is most exposed on the front side. Is there any way I can have it avoid the bottom half of the sphere when calibrating these angles of the L probe?

Thanks.

Parents Reply Children
  • If I remember correctly, the sphere is pointing forward 30 degrees from straight up. I am almost positive my vectors are correct, it's just that because PC-DMIS knows the angle of my sphere, it knows that the sphere is most exposed on the front side. When it calibrates the A0B180 angle for the L PROBE, it goes around the bottom of the sphere, which it does not have clearance to do. I know I can significantly limit my start and end angle but it's only for this angle and the ones close to it and I would prefer to not limit my calibration accuracy.  

  • If I'm understanding correctly then you have this sort of situation...



    You could always re-position / re-orientate the sphere for this problematic tip.  You just need to make sure you use the same "master" tip to define both sphere positions/orientations.