CMM calibration

[jpelletier2005]

Hello,
We have multiple CMMs on our site. One of them recently a Global Advantage is not repeating its calibrations. Example is , I can calibrate ,run my master part ( Which is normally around .002 deviation on average. 9 T-values that is checking for height ) and get -.0013 deviation on average. I recalibrate again and re-run the master part again and get .004 deviation. So just from recalibrating I have a .005 swing. I have shut down, cleaned , inspected the machine, tips, calibration sphere. We have re -run the same part 5 times loading and unloaded with same operator and get the same results 5 times in a row.
We did just have our yearly calibration done.
If I check my run charts they show before the calibration was done that we didn't have this issue.
What could cause this issue?

[JEFMAN]

Maybe the operator who made the calibration changed some parameters (sphere diameter, probing params...) and didn't re-changed them ?

[Jackarroo]

I have a 3° C Temperature swing in my "controlled climate", and my measurements can vary 4-6 Microns That I can easily see while measuring..

[Douglas]

no offense to calibration techs, but I've found probes/bodies left loose after calibrations, typically they like to remove the probe body to put their own on for calibration and I find mine put back less than finger tight, look for loose stuff would be my start

[BKulpa]

How do you setup your initial alignments?
Do you need to do an new manual alignment? Have you reset tip to nominal and recalibrated?

[jpelletier2005]

Please explain a little more about RESETING TIP TO NOMINAL !

[JEFMAN]

It's a checkbox in the calibration window.
You can select it or not.
If you don't work in english, the text can be different !

[JEFMAN]

Or here :



Reset Tips
The Reset Tips button resets any selected tips in the Active Tip List so that they are no longer calibrated. This provides you with a quick way to reset tip data back to their theoretical values. Previously, you had to delete and then add the tip back in to accomplish this same thing.
If you do not have any tips selected when clicking this button, you will be prompted to confirm whether or not you want to reset all the tips. If you choose Yes, then all the tips will be reset, otherwise no action will be taken.

[jpelletier2005]

So I found this in Active Tip List *T1A60B0 . The problem I have is that no matter how many times I calibrate , the * next to the angle doesn't go away. I have tried to delete this angle but get an error message that say " One or more selected tips cannot be deleted due to being explicitly referenced in at least one named set ". Does anyone have any clue as to what is going on? Every other angle in the list calibrated just fine and along with this angle the results look fine.
This angle is the first angle of the program I am having an issue with.

[Sora5]

That error means that tip is saved in one of your parameter sets. Cycle thru all your parameter sets and see which one has it selected and unselect/save. Then you can delete that angle.

When in doubt, delete that probe file and recreate it. It doesn't take long (unless you have a lot of parameter sets you have to recreate) and might fix a lot of underlying issues that isn't obvious.

[jpelletier2005]

To update There are 2 of those angles in the active tip list. 1 with an * and 1 without.