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Recent content by pmarc

  1. pmarc

    RMB for width as tertiary

    Burunduk, greenimi, I don't know what the right answer is. What I do know, though, is that the community is divided, with each side having valid arguments. I would also say that the decision on whether to stop or continue inspection when the datum features are nonconforming may depend on the...
  2. pmarc

    RMB for width as tertiary

    I wasn't thinking about reversing the order of inspection. I was thinking about whether the inspection needs to be stopped if a datum feature turns out to be non-conforming, or it can be continued.
  3. pmarc

    RMB for width as tertiary

    It's important, for example, if one wants to ensure that inspection of the part is not continued when the RAME size of the datum feature is greater than its MMB size. If it makes sense to stop inspection at this point is a whole different conversation though.
  4. pmarc

    RMB for width as tertiary

    7.11.4 Datum Features Applicable RMB When a datum feature or collection of datum features applies RMB in a feature control frame, the true geometric counterpart geometry originates at the MMB and progresses proportionally through the tolerance zone to make maximum possible contact with the...
  5. pmarc

    RMB for width as tertiary

    Isn't the requirement stated in para. 4.11.4 in the 2009 or para. 7.11.4 in the 2018?
  6. pmarc

    RMB for width as tertiary

    After giving it some more thought, I take back what I said. The illustration in the book is correct and I was wrong. Sorry for the confusion.
  7. pmarc

    RMB for width as tertiary

    I don't know. To me, the simulator should clearly touch both surfaces of datum feature C.
  8. pmarc

    RMB for width as tertiary

    The illustration on the left in the book does not look right to me. It correctly shows the tertiary datum feature simulator at RMB as a pair of two parallel planes perpendicular to A and centered on B, but the planes are not at the smallest possible separation from each other. The planes should...
  9. pmarc

    nX / nSURFACES notation can be used for all the GD&T character?

    The SEP REQT is used when multiple feature control frames are involved. The case being mostly discussed here is a single feature control frame with nX application.
  10. pmarc

    Datum Modifier Effects - Planar Surface

    If the artificial requirement is removed, there will have to be a contact between datum feature B and its simulator. So this will basically be return to what the 2009 version defined. But this would require accepting the fact that in certain cases of referencing datum feature at MMB (or LMB)...
  11. pmarc

    nX / nSURFACES notation can be used for all the GD&T character?

    Adding 2X in front of a flatness tolerance applied to a pair of nominally coplanar features does not make the features a pattern per Y14.5. In fact, the meaning of such a callout would ne no different than defining two separate flatness feature control frames - one for each feature. If the two...
  12. pmarc

    Datum Modifier Effects - Planar Surface

    greeinimi, I believe I've already answered the question in my last reply to Burunduk.
  13. pmarc

    nX / nSURFACES notation can be used for all the GD&T character?

    greenimi, That depends on what type of feature controlled by a runout tolerance we are talking about. If we are talking about cylindrical features, then yes, I would agree that there is a location component in the runout control. However, even then, at least per the 2009 and prior versions of...
  14. pmarc

    nX / nSURFACES notation can be used for all the GD&T character?

    It is OK to use nX/n SURFACES for form, orientation, and runout tolerances. The thing to remember, though, is that unlike for position and profile tolerances, the nX/n SURFACES notation applied to form, orientation, and runout does not create a pattern of tolerance zones. That is, each...
  15. pmarc

    Perpendicularity to 3 datums

    greenimi, Yes, I agree that the location of the interrupted feature is not clearly controlled. In my response, I tried to focus only on providing an answer to the original question.
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