Calibration spheres

[Angie Thomas]

Ok so I'm fairly new to all of this. I had to have a new fixture made to hold my calibration spheres. One of the spheres sticks up in the Z axis and the other sticks out in the Y. When I am trying to calibrate the top tip of a star probe on the sphere in the y axis the probe starts to come towards the sphere and then crashes into the table. It wants to go about 15mm into the granite surface! I don't have anything on that would tell it to move that far from the sphere. What could I possibly be missing?

[Matthew D. Hoedeman]

Are your tools defined properly? Straight up in Z would have a vector of 0,0,1 and the 'Y' tool should have a vector of 0,1,0 or 0,-1,0, depending on which way it points.

[Angie Thomas]

Yes that is all correct. I have 2 tool racks on the cmm. It calibrates 7 of the probes without a problem. The only tip that gives me a problem is tip one of the star probe.

[slesholdofthreep]

Try selecting MAN+DCC prior to measuring. This should clear up any problem caused by the tips not being properly related to one another.

[Angie Thomas]

When I did a MAN+DCC it worked for the first probe angle A0B0, but when it rotated to A0B90 it crashed into the table before trying to go to the sphere. Is there some other setting that there could be except for prehit and retract that could be throwing something off?

[slesholdofthreep]

I can't think of any other setting. Are you sure your probe build is correct? Sometimes probe and qual sphere files get buggy and if thats the case you'll need to delete the existing ones and recreate them.

[Matthew D. Hoedeman]

Yeah, try making a 'new' profile file that is exactly the same (different name) and see if it will calibrate.

Another thing you CAN do is to manually calibrate ALL the tips (no DCC at all!). This will 'force' Pcdmis to 'see' them where they really are, even if the file is bugged out.

[Bill **********]

Qualification spheres are backwards from every other vector used in PCDmis. The shank vector of the qual sphere points toward the ball. Is it possible that the vector for you qual sphere is backward? A quick way to tell is use a regular stylus and pick up the shank of your qual sphere as a manual cylindar. Start away from the sphere and move toward it using at least 3 rows and 3 hits per row. Dimension that cylinder with V and see that your qual sphere vectors match or are very close to the vector of the cylinder.

Bill

[AuRules]

Is it crashing on the way to calibrate and if it is there are some setting the will shorten your move around the sphere.

[JIM HARRIS]

Did you look in the probe utilitys under setup.There are some settings in there you can change.

[Angie Thomas]

It's crashing as it goes towards the sphere, but I think I'll have to start over with that probe. Thanks so much for the advice.

[Wes Cisco]

If that fails, as I think Matt said, try manually calibrating each tip angle, then try dcc calibration.