Position/ISO/New GD&T

[[Ed...]]

Hi,

I have this on the drawing!

Feature is plane from 18 points and A-A is plane from 16 points.

 

 

 

 

This is how I evaluate it, would it be right way?

How to evaluate this with New GD&T? 

[[Ma...]]

I would evaluate it as surface profile, but you did it correctly.

It should be "PlaneRoot" from 18x planes and A-A should be tangential element, which should be by default once applied here as datum.

[[Ed...]]

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Thanks,

I have another question, here I should use inner tangential for A-A?

 

[[Ma...]]

I am curious how you want to measure this, but your only option here is either make many lines and do tangential feature ( radius between lines ) or curves.

Then form a plane from each circle's center. But still it should be tangential element - in this case vector of that plane should be outwards from material.

[[Ed...]]

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I measured Datum A with 16 self centering points (ball Ø3.5), also checked with tangential feature, result was the same, so I chose faster measurement with self centering.

Thanks for help 🙂

Is there any source where I can read about LSQ, tangential etc. how and when to use them?

[[Ma...]]

I have just recently discovered from ZEISS Inspect software due strange behaviour.

According to ASME and ISO - datums are always as tangential element and elements used for axis are always perpendicular to previously defined element.

At least that's how i interpret it now.

[[ni...]]

Calypso_basic_ISO 5459 Section.pdf

good questions about best practices, for me I use inscribe and circonscribe only to have diameters values, for GD&T and datum I use Gauss wich is more stable (even with ISO I should use tangentiel for datum).

LEAST SQUARES DATUM DEFINITION.pdf

the least squares datum definition article explain some behaviors of the differents methodes (even it give me a headache, it's realy interesting)