Datum Reference Frames fo Composite Tolerences
Datum Reference Frames fo Composite Tolerences
(OP)
Question: Can you have the following callout? First tier - Profile of a surface w/in .030 to A-B-C. Second tier - Profile of a line w/in .010 to A-B-C.
I believe that the second tierwould cancel out the top. Please give me your thoughts.
Tim Martinez
Anaheim, Ca
I believe that the second tierwould cancel out the top. Please give me your thoughts.
Tim Martinez
Anaheim, Ca





RE: Datum Reference Frames fo Composite Tolerences
Marcelino Vigil
GDTP T-0377
RE: Datum Reference Frames fo Composite Tolerences
Profile of surface w/in .030 to A-B-C
Profile of a line w/in .010 to ?
Which datums do we need to use to lock the rotation but allow it to move positionally?
Thanks in advance,
Tim Martinez
RE: Datum Reference Frames fo Composite Tolerences
I can see the possibility of profile of a surface to A,B & C which controls the shape and location of the surface and is usually perpendicular to datum A.
Profile of a line is two dimensional and controls the shape of the shape and the location of the feature at its edge. One usually should never see profile of a line referencing three datums.
Yes, one could see profile of a surface .030 to A,B and C while the second level is profile of a line .010 (component of profile of a surface) to B & C. (not datum A).
Dave D.
www.qmsi.ca
RE: Datum Reference Frames fo Composite Tolerences
What you are describing sounds like exactly what this GD&T tip addresses. Go to this link and study what it says and it would be a good idea to bookmark the link too. There's a lot of good information there. From what I can see, there is no need for a "Profile of a line" specification. Just refining the lower tier as required while still using the Profile of a surface callout.
http://www.tec-ease.com/tips/may-03.htm
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