Evaluate cylindricity

[[Jo...]]

Hi, 

I'm evaluating a cylindricity, as can see, I'm trying all methods, and the diameter change is what is expected to be, but the cylindricity always gives the same result.

The evaluation of cylindricity should change depending on the method I choose to evaluate the cylinder, or not? 

Can anyone have an explanation for that?

[[Ch...]]

Changeing the parameter for the used fitting element should NOT change the results of a GD&T computation (exception is the usage of the geometry parameter that is available for location and position check but not for form checks like a cylindricity) Please have a look onto the GD&T introduction in the Zeiss Inspect Techguide to get more information about how GD&T computation works in the Zeiss Inspect Software (https://techguide.zeiss.com/en/zeiss-inspect-2023/article/introduction_to_gdat.html)

Reason for the behaviour can be found in the mentioned introduction:

"The construction of a fitting element is based on a selection on the actual data. The software includes this selection in the GD&T analysis of the fitting elements. Based on this selection, the software computes the tolerance or the datum. During computation, the software ignores the computation method (e.g. Gaussian, Chebyshev, constraints) that was used to create the fitting element. This procedure ensures that the software always complies with the prescribed fitting methods of the standards (Defaults)."

We are aware, that the current issue of the standard introducing a new modifier allowing you to change the computation method but this modifier is not (yet) supported.

 

Hope this helps

Christoph Schult