Unable to calibrate 2mm ball probe

Reboot everything, machine and all, so you can re-home the machine also clean the scales real good before you Home the machine. also make sure there isn't some other calibration sphere chosen.

1) Turn everything off and then back on again

2) Clean everything (scales and all)

3) Select a tip to be your MASTER. Your 2X20 should work well. Say YES sphere has moved and do the manual point. ONLY CALIBRATE T1A0B0 IN THIS STEP. Because you said yes and only did T1A0B0, it is now your master.

4) Now calibrate all other probes and make sure you say NO SPHERE HAS NOT MOVED. Now, all of these subsequent calibrations are related back to your master.


If your machine is calibrated and in good working order AND you followed the above sequence correctly, then you should be good.

If you're still failing, then F9 the probe and verify that all of the components are correct and match your physical build. If the build is correct and you're still failing, check back.

If you're just hitting "mark all" and saying YES THE SPHERE HAS MOVED, then you're confusing DMIS and not setting up an appropriate master/slave relationship for your probe files. This seems like it might be your problem.

1) Turn everything off and then back on again

2) Clean everything (scales and all)

3) Select a tip to be your MASTER. Your 2X20 should work well. Say YES sphere has moved and do the manual point. ONLY CALIBRATE T1A0B0 IN THIS STEP. Because you said yes and only did T1A0B0, it is now your master.

4) Now calibrate all other probes and make sure you say NO SPHERE HAS NOT MOVED. Now, all of these subsequent calibrations are related back to your master.


If your machine is calibrated and in good working order AND you followed the above sequence correctly, then you should be good.

If you're still failing, then F9 the probe and verify that all of the components are correct and match your physical build. If the build is correct and you're still failing, check back.

If you are still having an issue after following these steps, you could have a corrupted probe file or cal sphere file. I have had both of them become corrupted before (not at the same time... yet). These files becoming corrupted is not very common but it does happen. I've had a corrupted probe file maybe 10 times in the 6 years I've been doing this. I've had a corrupted cal sphere file only once.

In addition to what everyone else said, double check your probe build and verify you have all the correct components. I've had a very similar issue before and it was because I had built the probe up with the incorrect head and the program thought the ball was 2mm lower than it actually was.

I tried all of that stuff and it helped, but still didn't completely fix the issue. I did find a very old backup probe file that I was able to get the calibration to take with. I will definitely be more careful with making sure to not be reckless with my calibration in the future, and with keeping regular backups of probe files.

Thank you so much!

I did that when I went to the Level 3 class. Their machines use the Leitz probe heads and I use a PH20MQ at work... oops...

Things not mentioned include:

1) Check to see how far THEO and MEAS is in the results file for that probe... if calibration error is encountered and the difference is big, check the 'reset to theo before calibration' box and it will likely calibrate
2) That old probe file that worked, this does not mean your probe file was corrupt at all, it might have just had the above issue and the old file had meas values closer to theo and it worked.
3) For your master probe, THEO and MEAS values must always be exactly the same for x,y,z values... if there is any difference at all it is error. A small difference in diameter offset is expected.
4) If theo and measured values are the issue it can also work to increase prehits in the measure window... but better to reset to theo.
5) It is best to use a dedicated master probe, never measure with it only set the ball. If you do measure with your master tip and want to re-calibrate it... tell pcdmis the ball moved even if you did not move the ball and calibrate only that tip not along with other tips/angles, then you must recal everything to be certain. If the master tip gets bent in use then only doing this will correct it and maintain other tip correlations to it.
6) If the machine was homed after the last time the ball was moved, consider it invalid and tell pcdmis the ball has moved. You will always need to use the master to set sphere location after machine was homed, every time you home it the ball location is lost so to speak

NEVER CALIBRATE THE MASTER TIP WHILE SAYING THE BALL DID NOT MOVE. Never recal the master tip and say the ball did not move, you need to lie to pcdmis and say the ball moved for the master tip even if you did not move it