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"Default" Math Vs "Legacy"?

Cumofogabriel
What are we calling the new default Geo-Tol math? "New Math"? "Default Math"?
I remember this gun fight a loooong time ago, it ended up bad for Hexagon and us also.
what I mean is:
The "New Math" best fits a little too aggressive for me compared to "Legacy". Last time I had reports coming out with perfect true position our customer Lockheed Martin mopped the floor with Pc-Dmis and started the whole ISO Best-Fit shootout, disallowing us to use Pc-Dmis best fit algorithms. The "New Math" best fits also. Here is a comparison:



What do you think?
and can we come up with a disparaging term like "New Math" other than "Geo-Tol"? or "Geo out-of Tol"?

thx
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  • #26.1
    commented
    Yesterday, 06:06 PM
    It seems like the "I can't validate its output" is a function of your level of experience and knowledge.
    You don't use your gut to validate confidence in a process, you use math.​

    Well said and I totally agree.

    For the record, we recently went through a validation process with a well known US aerospace OEM. They have their own, internal process for software validation which they perform every couple of years to inform their decision on which metrology software packages they use and whether they update to a new version or not. They fully approved our new math and GD&T capabilities and are in the process of disseminating that information to their in-house CMM programmers and suppliers. Hexagon is also working closely with NIST in an effort to have them verify our "new math" - constrained L2 (which, incidentally, they supported as the default datum math solution when proposed to both ASME and ISO) . Historically, NIST have only offered certification for Least Squares calculations. I believe PTB (Germany) offer Least Squares and Chebyshev certification but, to date, nobody has been able to provide certification for GD&T.​
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  • #26.1
    commented
    Yesterday, 06:06 PM
    It seems like the "I can't validate its output" is a function of your level of experience and knowledge.
    You don't use your gut to validate confidence in a process, you use math.​

    Well said and I totally agree.

    For the record, we recently went through a validation process with a well known US aerospace OEM. They have their own, internal process for software validation which they perform every couple of years to inform their decision on which metrology software packages they use and whether they update to a new version or not. They fully approved our new math and GD&T capabilities and are in the process of disseminating that information to their in-house CMM programmers and suppliers. Hexagon is also working closely with NIST in an effort to have them verify our "new math" - constrained L2 (which, incidentally, they supported as the default datum math solution when proposed to both ASME and ISO) . Historically, NIST have only offered certification for Least Squares calculations. I believe PTB (Germany) offer Least Squares and Chebyshev certification but, to date, nobody has been able to provide certification for GD&T.​
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