Calibration of style d 0.3 mm

[[Di...]]

(There is head CMM Vast Gold, )How can I calibrate style with d=0.3 mm(feature)?
I think: Stress (about 30% mH) and Taper angle of Sphere (less 80). I have never done it, who know something about it...

[[SH...]]

First check whether your machine is capable of working with 0.3mm probe..

[[Ro...]]

With a vast gold, i have difficulty with a 0.5mm.

[[Is...]]

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I used to have problems, but were related to the quality of the probe… no issues with Zeiss probes (0.3 , 0.4 & 0.5)

[[Cl...]]

We successfully use a 0.3 with our Vast XT Gold. You must reduce the probing dynamic to 25%

[[To...]]

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Not sure if (less 80) is a typo but using less than 180° is quite common in this scenario especially since you probably have a 30mm reference sphere which will likely cause the stylus shank to get in the way. You'll know it's interfering due to the higher sigma (S) values. I typically reduce the the sphere coverage in 5° increments until the sigma falls to an acceptable value. Of course, this is not possible with passive qualification on an XXT sensor.

[[Da...]]

I have used 100mN with 50% probing dynamic and 150 degree coverage on a 30mm diameter reference sphere with no problems.

[[Di...]]

Thanks All. I'm going to use 50mN dinamic probe 25% (when I calibration d=0.5 with 100 coverage of sphera (d=30 mm) and stress 100mN ).

[[Gr...]]

We have a RDS VAST TL1 head on our Contura G2 and a RDS VAST TL3 head on an ACCURA II.
Until we purchased a 8 MM reference sphere we had a 30 MM reference sphere we used for all our stylus.
We have qualified stylus as small as 0.25 MM and would get good results by changing Sphere Coverage in the Probing system qualification window.
I noticed Tom Oakes posted this was not possible with a passive sensor. My question is why is it not possible?
We done it for 9 years until we got the 8 MM sphere.
Greg Kozera

[[To...]]

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The passive qualification uses 180° of the sphere, not matter what your coverage angle is set to. The geometry qualification CAN use less than 180°. However, the bending parameters are based on the scanning portion so if your probe is shanking out, the bending parameters could be skewed. Now, to be fair, I have not tested this in years but I still believe it to be true.

[[Ri...]]

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This is a true statement.

[[Gr...]]

Thank you for the explanation as to why this does not work with passive sensors. What confuses me is we were able to qualify and use the tiny stylus with good results. We set the Sphere Coverage to 120° for the 0.25 MM stylus using the 30 MM reference sphere and while watching it qualify never saw the machine go beyond the 120°. The R value came out at .129 and S value at .0013. Subsequent qualifications using the 8 MM reference sphere yielded near identical results.

[[To...]]

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During the scanning portion, too?

[[Gr...]]

Yes sir. We started at the 180° and kept dropping the angle until we hit 120° as the working angle.
I must tell you Tom you have been a great source for answers to a number of questions I have had over the years, and I need to thank you for that.
Greg Kozera

[[Ca...]]

Hello,

I use D0.2 / D0.3 / D0.5 probes with a R15 Sphere.

I use as calibration settings 145° , 65Nm / 10% works fine for me and stable.