PR 253175 GD&T "position" is per standard not confo

huangyhg

<< Lothar Schafer  --  02/07/08  18:09:32>>
Our curtomer reclaims that with the new GD&T he gets different results for position tolerances. For further information see the attached PDF file. The results in version 3.5 and 3.7 (made in 4.2 with legacy dimensions) are reasonable and conform with the ISO norm we use in Europe. The last result in 4.2 is not reasonable. this has to do with the evaluation type "rectangular to axis", that is default in this calculation type. If you activate this in 3.7 (legacy) then you get the same WRONG result.
I found in the help file that you have only one chance to switch off this rectangular evaluation, by evaluating just a point or a sphere. We tried this and there is no change of the values, so this seems to do not work. Anyway it is stupid, because how can you evaluate a circle with sample hits in 3 dimensional position using MMC?
What is needed is the possibility to switch off the rectangular evaluation with a toggle box. Please remember, not the whole world measures in ASME standard, we need to have an easy way to choose, otherwise whole Europe will cry very loud. The customer does not accept this solution, from their point of view they cannot use PC-DMIS with new GD&T because of this restrictions.

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huangyhg

<< Don Turcotte  --  05/06/08  16:52:31>>
I have modified the feature control frame command using Frank Herr's suggestion such that if the registry setting Option/UseISOCalculations is true (1), the FCF true position will be done with PerpToCenterline false (ISO 1101).  If Option/UseISOCalculations is false (0), the FCF true position will be done with PerpToCenterline true (Y14.5).  The registry setting Option/UseISOCalculations is by default false (0).

I have made this change to V42R MR2, V43R, as well as V42 beta, V43B, V44B.

Files inserted to server
------------------------
V42\DIMENS\FEATCTRLFRM.CPP
V42R\DIMENS\FEATCTRLFRM.CPP
V43B\DIMENS\FEATCTRLFRM.CPP
V43R\DIMENS\FEATCTRLFRM.CPP
V44B\DIMENS\FEATCTRLFRM.CPP
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huangyhg

T:\V44B\DIMENS\FEATCTRLFRM.CPP(26398):        BOOL bPerpToCenterline = (global_UseISOCalculations ? FALSE: TRUE); // PR253175 - never use perp to centerline with ISO
  T:\V44B\DIMENS\FEATCTRLFRM.CPP(26426):        BOOL bPerpToCenterline = (global_UseISOCalculations ? FALSE: TRUE); // PR253175 - never use perp to centerline with ISO