Concentricity error on Pc-Dmis 2020R2

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  • Concentricity error on Pc-Dmis 2020R2

    Hello, I'm having trouble switching to R2. I have three all with Pcdmis 2020R1. When I opened Pcdmis r2 anything with concentricity gave me errors.

    The error message I get is : Concentricity tolerances require input features that are concentric with the datum reference frame.

    Now I did not write these programs and I'm afraid to change anything with out knowing if it will change the results. These are all programs that are used for production checks.

    Also I noticed the profiles don't have a plus or minus tolerance. Is the result still the same?

    Any help understanding this change will help me greatly Thanks in advance!

  • #2
    Check your considered feature and datum feature THEO values. It is possible that your nominal (THEO) values are not perfect, which would cause this error. For example, if your primary datum is a cylinder with axis along Z, make sure that the THEO vector is <0, 0, 1> and not <0.000034, -0.000430, .99999987> or something along those lines.


    • #3
      I did check all of these just now and it still giving me the same error .


      • #4
        the is what it looks like on my screen
        Attached Files


        • #5
          Can you show the groove diameter and datum B in the edit window?


          • #6
            yes here they are
            Attached Files


            • #7
              Your circle has a THEO vector along I (<1, 0, 0>) and your datum has a THEO vector along K (<0, 0, 1>).

              In essence, you are asking PC-DMIS to compute the concentricity of two "perpendicular" circles, which is undefined.

              As far as your profile tolerance is concerned, the actual value for profile has been changed with ASME Y14.5.1-2019 such that the actual value is the quantity (t + 2g) where t is the size of the tolerance zone and g is the growth parameter. The tolerance zone expands or contracts about the nominal surface to fully enclose the measured surface. The amount that it expands or contracts is equal to g. Thus, a conforming part will have a negative value of g and a nonconforming part will have a positive value of g. The reported (MEAS) value in PC-DMIS is equal to the actual value of (t + 2g). This new interpretation does not change conformance, but rather yields a single actual value instead of the older definition which required two values (max/min).
              Last edited by JacobCheverie; 12-01-2020, 08:32 AM.


              • #8
                I had this on a new part.

                My original alignment datum plane was Z+, rotational line was Y+, and origin point was a circle on the y- work plane. I created a perpendicular plane, using my datum plane, and the origin point for the angle of rotation. My rotational line was (basically) to the Y axis, so, I took a single hit on the origin point at the planar end of the part. I called the created plane, as a double datum (my planar datum was Datum A, So, I called the perpendicular plane Datum AA), so as not to confuse that it was a planar datum not called out on the print.

                Then, in the middle of reporting, I created a new 3-2-1 alignment, using that plane AA, the rotational line, and the datum y origin point. I took the dimension, and afterward, recalled the previous alignment.

                This worked for me.


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