http://gdtseminars.com/blog/2008/03/06/dimensions-with-datum-targets/ Geometric Dimensioning & Tolerancing tips, questions and issues Fri, 21 Nov 2008 20:41:33 +0000 http://wordpress.org/?v=2.3.1 http://gdtseminars.com/blog/2008/03/06/dimensions-with-datum-targets/#comment-208 John-Paul Belanger Tue, 27 May 2008 22:34:38 +0000 http://gdtseminars.com/blog/2008/03/06/dimensions-with-datum-targets/#comment-208 Sorry for the delay in replying, Mario. Basic dimensions themselves have no tolerance, but they point to a feature that usually does have a tolerance. That tolerance is shown in the form of a GD&T "feature control frame." So for quality control tracking, any statistical data are not really looking at the basic dimension, but at the tolerance given in the feature control frame. It's a minor point, but remember that the purpose of the basic dimension is merely to avoid having us mistakenly apply title block tolerances to that number. My blog entry about basic dimensions and datum targets emphasized that there is no direct tolerance, but the datum targets would never be measured or tracked by quality control. Sorry for the delay in replying, Mario. Basic dimensions themselves have no tolerance, but they point to a feature that usually does have a tolerance. That tolerance is shown in the form of a GD&T “feature control frame.” So for quality control tracking, any statistical data are not really looking at the basic dimension, but at the tolerance given in the feature control frame. It’s a minor point, but remember that the purpose of the basic dimension is merely to avoid having us mistakenly apply title block tolerances to that number. My blog entry about basic dimensions and datum targets emphasized that there is no direct tolerance, but the datum targets would never be measured or tracked by quality control.

]]> http://gdtseminars.com/blog/2008/03/06/dimensions-with-datum-targets/#comment-202 Mario Varela Thu, 01 May 2008 21:42:18 +0000 http://gdtseminars.com/blog/2008/03/06/dimensions-with-datum-targets/#comment-202 I work in Quality Control and sometimes we are required to prepare dimensional reports that have Basic Dimensions. How can that be done if they have no tolerances? I work in Quality Control and sometimes we are required to prepare dimensional reports that have Basic Dimensions. How can that be done if they have no tolerances?

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