Profile callout, again

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  • Profile callout, again

    Guys, is this a legit callout having a SR .812 +0-.002 and a unilateral profile .002 ?

    They want me to measure the profile, I just think it completely contradicts the SR callout. SR should be a BASIC. How can I have both?
    B&S One
    PC-DMIS CAD v2014

    Romer Infinity

  • #2
    To me it seems that the SR is to define the spherical curve (radius) and the profile is to center the spherical curve about -A-.

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    • #3
      Originally posted by Nano Vujkovic View Post
      To me it seems that the SR is to define the spherical curve (radius) and the profile is to center the spherical curve about -A-.
      I see what you saying, I didn't even think about that. So, the profile is only in one direction, along the center, and it will not interfere with the SR callout
      B&S One
      PC-DMIS CAD v2014

      Romer Infinity

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      • #4
        Nano, Profile is a unilateral toll, so in theory if the SR is .813, the profile would be still good if the SR is right on center?
        B&S One
        PC-DMIS CAD v2014

        Romer Infinity

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        • #5
          Are the blood spatters on the print from you or the engineer?

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          • #6
            Originally posted by Josh Carpenter View Post
            Are the blood spatters on the print from you or the engineer?
            Lol i wish!
            B&S One
            PC-DMIS CAD v2014

            Romer Infinity

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            • #7
              In my opinion 0.812 rad. should be basic.
              sigpicIt's corona time!
              737 Xcel Cad++ v2009MR1....SE HABLA ESPAƑOL

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              • #8
                What makes you think the profile is unilateral? There are no modifiers in the FCF or other indications on the print that would establish this. Equal bilateral is the default condition unless otherwise specified.

                You have a basic dimension from the shoulder and then the spherical radius +0/-.002 struck from that. This controls size and axial position. This does not control orientation or radial position relative to axis A. The surface profile control is intended or handle that. Since you have no basic radial dimension and only an implied "0" relative to A it could be argued that this control does not contradict the +0/-.002. I think they would lose this argument in court since it isn't specifically supported by the standard but it does pretty much make sense logically.
                Last edited by DaSalo; 05-06-2015, 09:24 PM. Reason: Thought about it more..
                2013MR1 SP6
                Global Frames, Tesastar-M Heads, LSP-X1M/H Probes

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                • #9
                  Yes, I dont know what I was thinking, Bileteral is what I meant.

                  Here is what I don't quite understand, since its Bileteral Profile, meaning the SR can be .001 in both directions, right? Or not, because it to -A- only??
                  Originally posted by DaSalo View Post
                  What makes you think the profile is unilateral? There are no modifiers in the FCF or other indications on the print that would establish this. Equal bilateral is the default condition unless otherwise specified.

                  You can think of the spherical radius tolerance as a refinement of the surface profile. They could have written it like this (SP = Surface Profile):

                  [SP|.002|A]
                  [SP|.002 U -.001]
                  B&S One
                  PC-DMIS CAD v2014

                  Romer Infinity

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                  • #10
                    The intent seems to be that you evaluate the radius first to establish that the size and axial location meets the +0/-.002 requirement. Then you evaluate the radial location and orientation of the surface relative to axis A. You are right that surface profile has the likely unintended consequence of controlling the size again after it has already been controlled. My best guess is that they intended size to be controlled by the +0/-.002 dimension only and intended the surface profile dimension to control radial location and orientation relative to A. Since there is no basic dimension provided it can be argued (perhaps not legally) that the surface profile zone is not at a fixed radius but rather floats at the mercy of the +0/-.002 dimension.

                    I think they could have covered it better if they had identified the shoulder as B, set the radius as basic, and then applied this control:

                    [SP|.002 U -.002|A|B]
                    Last edited by DaSalo; 05-06-2015, 09:30 PM.
                    2013MR1 SP6
                    Global Frames, Tesastar-M Heads, LSP-X1M/H Probes

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                    • #11
                      Originally posted by Roberto View Post
                      In my opinion 0.812 rad. should be basic.
                      +1
                      sigpic...engineering

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                      • #12
                        That is illegal call out, you have moving target (SR .812+0-.002) for Profile of the surface.
                        sigpic...engineering

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                        • #13
                          So If I wanted to check the profile to the print, how would I do it with Legacy? How would I indicate that I only want a Profile to -A- and not the shoulder?
                          Originally posted by DaSalo View Post
                          The intent seems to be that you evaluate the radius first to establish that the size and axial location meets the +0/-.002 requirement. Then you evaluate the radial location and orientation of the surface relative to axis A. You are right that surface profile has the likely unintended consequence of controlling the size again after it has already been controlled. My best guess is that they intended size to be controlled by the +0/-.002 dimension only and intended the surface profile dimension to control radial location and orientation relative to A. Since there is no basic dimension provided it can be argued (perhaps not legally) that the surface profile zone is not at a fixed radius but rather floats at the mercy of the +0/-.002 dimension.

                          I think they could have covered it better if they had identified the shoulder as B, set the radius as basic, and then applied this control:

                          [SP|.002 U -.002|A|B]
                          B&S One
                          PC-DMIS CAD v2014

                          Romer Infinity

                          Comment


                          • #14
                            Originally posted by Roberto View Post
                            In my opinion 0.812 rad. should be basic.
                            I agree with you, and I also think the Profile should have been unilateral since they want the Rad -.002
                            B&S One
                            PC-DMIS CAD v2014

                            Romer Infinity

                            Comment


                            • #15
                              This print does a few things that make little sense.

                              First, the .500 basic is irrelevant. Neither the shoulder or the SR are datums, so the .500 goes from nothing to nothing. It can't define anything. It should have been datum B on the shoulder to use that .500.

                              Who wants to do some CAD math and see what max and min size radius can fit within the .002 wide profile tolerance zone?

                              Either way, I think it should be one or the other. Just like the argument of toleranced Radius versus Profile of a radial surface.

                              A spherical radius has no orientation, if you spin it, it is always a sphere. The control then is its location to cylinder A and form.
                              "This is my word... and as such is beyond contestation."

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