probe won't stay calibrated

[kendo]

I dialed in the probe stylus 3 times today and each time I check it, its off again

yesterday, the machine alarmed out in the middle of a toolchange due to low air pressure
The probe was in the ATC pocket and during the recovery process it dropped to the floor. The stylus broke and when I installed a new one and calibrated it, this problem started.
Other than this calibration problem, the probe is working perfect with no visible damage or sloppy loose-ness anywhere

something else that may or may not be related:
the spindle is leaking air
you can hear it and feel it whether theres a tool in the spindle or not
the air is leaking directly out through the spindle taper
this was noticed 1st just today, just like the probe problem

[wcbob]

Whats not staying calibrated the length or dia? Is the probe head moving in the holder are the jack screws tight? can you spin the probe body? How do you know it's not staying calibrated.

[kendo]

by calibrated I mean "dialed in"
its the TIR thats supposed to be .0002 or less measured at the center of the ball tip
the screws are all tight, the stylus is tight, and no the probe body isn't spinning in the holder.
I can tell because when I walk up and spin the probe in the spindle I can see the ball tip wobbling about

[kendo]

OK think I figured it out
thought I was going crazy there for a minute
the probe body had worked its way out of the holder a little bit
I could just barely see a gap of light between the two when looking directly at the side
I noticed while dialing in the stylus that if I barely layed a finger on the probe body, the indicator needle would swing all over the place
so I took the whole thing out of the spindle, removed the two upper setscrews, loosened the four lower screws until the probe body was free and then re-installed and tightned all the screws.
When I did that I noticed the gap was gone and then when I re-calibrated it the TIR stayed the same after multiple tool changes

[Mic6]

Nothing like some aggravation relief

[Cory]

by calibrated I mean "dialed in"
its the TIR thats supposed to be .0002 or less measured at the center of the ball tip
the screws are all tight, the stylus is tight, and no the probe body isn't spinning in the holder.
I can tell because when I walk up and spin the probe in the spindle I can see the ball tip wobbling about

I don't have my manual in front of me, but I'm pretty sure Renishaw only calls out the TIR to be 0.010 or less. As long as you don't take the probe out of the machine and rotate it 180* when you put it back, when you calibrate the probe the software will account for any runout in the probe tip.