Probe verification results

[[Ma...]]

Howdy, I was wondering if these are generally decent number for a probe verification program or if something is wrong with our XTR head. Master reads zero.

Vertical probe DK3 L58

[[Ma...]]

I personaly dislike form value - cleaned probe and sphere? Run more than once?

[[Ch...]]

I only know such values from defective dirty probes or maybe a disc probes. Maybe you can mak a scan over the ref. sphere? Than you can see whats wrong.

If the cz-ref probe is good I think your head is ok.

 

Once we also had a loose ruby ball.

[[Ma...]]

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Cleaned probe and sphere yes, From 5 runs it averages the following;

X: -0.0003    High -0.0001   /   Low -0.0004

Y: 0.0016    High 0.0017  /  Low 0.0016

Z: 29.99965     High0.0018  /  Low 0.0014

Form: 0.0358    High 0.0338  /  Low 0.0336

My suspicion came from a program that I have been developing that has been in the work for the last few months, Same part, same program, same characteristic. The last run a 3 weeks ago reported a radial runout of 0.038mm, When ran last night I received a result of 1.084mm. I had found that the datum bore diameter was measuring 0.8xxxmm bellow nominal, no clue why. The inspection report from 3 weeks ago shows the diameter in spec and nothing was changed in the program sense then. No memorable Hard crashes in the last 3 weeks, just slow bumps. 

[[Ma...]]

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I do have an identical sister probe on my desk ill swap on to see if that changes any. In my eyes this looks like a pretty decent PD, minimal masking. 

[[No...]]

I once had a stylus that was loose on the threaded end of the shaft. The movement was barely noticeable but resulted in similar effects

.

[[Je...]]

What Norbert says.
Is this a probe with a carbone-shaft? I use 3mm-probes with an overall-length of 75 mm, and I often found, that this shafts can be broken, without seeing it by looking on it.

Martins suggestion also is not wrong, but I woult think, that a dirty probe or sphere shoult result in a higher diameter value, not a lower. In your case I would first change the probe, just to be save about

Edited March 3

[[Ma...]]

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Carbide shafts with ruby tips. Changed probes and got similar results. Have checked for broken shafts and found nothing yet.

[[Ma...]]

If I was you I would definitely look for graphical evaluation with form instead of profile to see if that form is from some random bumps or it shows some sort of shape ( like diameter in shaft axis is wider and perpendicular will be smaller ). That could possibly show where are that form or other deviations comming from.

Form will ignore nominal values. In some cases can be profile more benefitial.

[[Cl...]]

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I measure daily and track several "master parts", to verify the probes/cmm. The "master part" is initially measured several (20-30 times)

and all that data is used to calculate an average with a min & max in which the master part must fall within.