AndrewTT
Mechanical
- Jul 14, 2016
- 261
4.2 APPLICATION
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I understand that the note does not allow me to leave off the datum references in a FCF. I have no idea what the note does for me though. Can someone shed some light on what the intent of this note is? Can anyone provide a drawing that utilizes this note and explain what it accomplishes?
Thank you!!
Orientation and location controls require one or more datum reference frames established by datum targets or datum features (see Fig. 4-1).
Dimensions may be directly toleranced or indirectly toleranced in the case of basic dimensions and geometric tolerancing. Where directly toleranced dimensions are used to locate or orient features, and it is necessary to relate the dimensions to a datum reference frame, the desired order of precedence shall be indicated by a note such as
UNLESS OTHERWISE SPECIFIED, DIMENSIONS ARE RELATED TO DATUM A (PRIMARY), DATUM B (SECONDARY), AND DATUM C (TERTIARY)
This note is not to be used in lieu of indicating datum feature references in a feature control frame for geometric tolerancing applications.
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I understand that the note does not allow me to leave off the datum references in a FCF. I have no idea what the note does for me though. Can someone shed some light on what the intent of this note is? Can anyone provide a drawing that utilizes this note and explain what it accomplishes?
Thank you!!