What is the proper way to measure profile per asmey14.5-2008?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • What is the proper way to measure profile per asmey14.5-2008?

    What is the proper way to measure profile and does pcdmis do it properly per ASMEY14.5?

    PER THE EXAMPLE BELOW, WHAT IS THE REPORTED PROFILE MEASUREMENT?
    Attached Files
    Che Guevara is a communist scumbag.

  • #2
    Per ASME Y14.5.1M-1994, the "actual value" for a profile tolerance is actually two values, those being the farthest deviation from nominal on each side (into the material, out of the material).
    Per ASME Y14.5.1-2019, the actual value for a profile tolerance is the single farthest deviation from nominal (either direction) multiplied by 2.

    Comment


    • #3
      Like JacobCheverie said, per 2009 or earlier you would need the value of the least material point on the surface plus the 0.001" most material point for the profile measurement.

      Per 2018, if the point shown is the largest deviation from nominal, then the measured profile would be 0.002".
      153010 Global Advantage w/ LSPX1H_T Analog Probe
      7107 Global Classic TP20
      2019R1 SP1 CAD++

      Comment


      • BIGWIG7
        BIGWIG7 commented
        Editing a comment
        so how much is the profile out of tolerance in my example?

    • #4
      so does pcdmis give me the wrong answer when I select ASME for profile?
      Che Guevara is a communist scumbag.

      Comment


      • #5
        You get +/-0.00075 tolerance for a single point, so OOT by 0.00025
        sigpic
        Originally posted by AndersI
        I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

        Comment


        • BIGWIG7
          BIGWIG7 commented
          Editing a comment
          but how is that possible? I thought you doubled the deviation. so if my deviation is .001'' x 2= .002''
          with profile of .0015 = +/-.00075
          out of tolerance = 1.00025
          right?

      • #6
        profile to datum(s) is form & location. TOTAL tolerance of 0.0015" gives 0.00075" in each direction (form only is like position, only a positive value, and not what we have here).

        Profile reporting has changed with just about every version of Pcdmis is seems. First one way, then another way (and them saying, old way wrong, new way right) then next version (3rd) goes back to what it was in the first version. If his deviation is 1.001" then he needs a minimum of 0.002" for his profile tolerance for it to be in tolerance, and that is what it reports for PROFILE dimension, the deviation is what is NEEDED to be in tolerance, not a 'real' number that tells you how much in/out. So it would appear that it is 0.0005" OOT, but that isn't correct. That single point is only 0.00025" OOT. But, that is a unidirectional deviation (not a PROFILE deviation), if you double the deviation (to get the tol zone size) you must double the OOT value.

        This is why it has been said for YEARS that PROFILE dimension isn't enough BY ITSELF, you also need the MIN/MAX values, and the MIN/MAX compare to 1/2 of the total tolerance zone (for form & location)
        sigpic
        Originally posted by AndersI
        I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

        Comment


        • #7
          Just a note, your answer will depend on which standard you are working to. You mention ASME Y14.5-2008 but there is no such standard. Do you mean 2009? Or perhaps 2018?

          Comment


          • #8
            Measuring Profile is pretty straight forward. You just take enough hits along the surface to satisfy yourself that you have enough coverage to capture the highs and lows. Reporting has always been a problem. You can't reduce it down to a single meaningful number. If the profile met size and shape requirements, the single number could be meaningful. But when you are out of tolerance there are a lot possibilities. Shape could be right but too much material, Shape could be right but not enough material, Shape could be right but skewed to the datums or Shape is way out of shape.

            Comment


            • BIGWIG7
              BIGWIG7 commented
              Editing a comment
              ok so what is the correct way to report it? is pcdmis's way correct or not?

          • #9
            Originally posted by kingsld1 View Post
            Measuring Profile is pretty straight forward. You just take enough hits along the surface to satisfy yourself that you have enough coverage to capture the highs and lows. Reporting has always been a problem. You can't reduce it down to a single meaningful number. If the profile met size and shape requirements, the single number could be meaningful. But when you are out of tolerance there are a lot possibilities. Shape could be right but too much material, Shape could be right but not enough material, Shape could be right but skewed to the datums or Shape is way out of shape.
            This is why (IMO) reporting "T" for each point is superior for seeing if the part is good or bad and where it is bad if it is bad. PROFILE 0.0015" = +/-0.00075" all day long for each point, no possibility of not understanding it.
            sigpic
            Originally posted by AndersI
            I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

            Comment


            • VinniUSMC
              VinniUSMC commented
              Editing a comment
              This for sure. T values instead of "Profile" (reporting in PC-DMIS).

          • #10
            Originally posted by Matthew D. Hoedeman View Post

            This is why (IMO) reporting "T" for each point is superior for seeing if the part is good or bad and where it is bad if it is bad. PROFILE 0.0015" = +/-0.00075" all day long for each point, no possibility of not understanding it.
            Graphical Reporting is almost a must as well. A column of numbers can be hard to visualize.

            Comment


            • #11
              Originally posted by kingsld1 View Post

              Graphical Reporting is almost a must as well. A column of numbers can be hard to visualize.
              Mine IS all graphical (w/ numbers). Small example:

              Last edited by Matthew D. Hoedeman; 04-23-2021, 08:55 AM.
              sigpic
              Originally posted by AndersI
              I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

              Comment


              • #12
                Originally posted by JacobCheverie View Post
                Just a note, your answer will depend on which standard you are working to. You mention ASME Y14.5-2008 but there is no such standard. Do you mean 2009? Or perhaps 2018?
                yes, is there a difference between 1994, 2009, and 2019?
                Che Guevara is a communist scumbag.

                Comment


                • #13
                  ASME Y14.5.1 sets the definition of the actual value of a profile measurement. There are only two editions, namely 1994 and 2019, and each edition has a different definition of the actual value of a profile dimension.

                  If your drawing is to Y14.5-1994 or Y14.5-2009, then you must use the actual value definition from Y14.5.1-1994.
                  Now Y14.5-2018 is a bit ambiguous about which math standard to use, but the only technical reference is to Y14.5.1-1994.

                  Unless I am missing something, Y14.5 does not point to Y14.5.1-2019 as of yet. Therefore, unless there is some default requirement to use the latest revision of a referenced standard, I guess you should use the actual value definition from Y14.5.1-1994 which is min and max deviation.
                  Last edited by JacobCheverie; 09-30-2020, 01:46 PM.

                  Comment


                  • #14
                    Originally posted by Matthew D. Hoedeman View Post

                    This is why (IMO) reporting "T" for each point is superior for seeing if the part is good or bad and where it is bad if it is bad. PROFILE 0.0015" = +/-0.00075" all day long for each point, no possibility of not understanding it.
                    agreed, but reporting the T value does not calculate profile truly per the standard. technically the worst T value should be doubled according to the spec.
                    Che Guevara is a communist scumbag.

                    Comment


                    • Matthew D. Hoedeman
                      Matthew D. Hoedeman commented
                      Editing a comment
                      depending on the spec. For the PROFILE (total, over-all, all-inclusive part profile) but for individual points, the "T" is correct

                    • BIGWIG7
                      BIGWIG7 commented
                      Editing a comment
                      T is correct in seeing the deviation, but it does not correctly report actual profile measurement. you would have to double your worst T to report profile correctly.

                    • VinniUSMC
                      VinniUSMC commented
                      Editing a comment
                      No, not for ASME before 2018/9. There is no doubling.

                  • #15
                    Originally posted by JacobCheverie View Post
                    ASME Y14.5.1 sets the definition of the actual value of a profile measurement. There are only two editions, namely 1994 and 2019, and each edition has a different definition of the actual value of a profile dimension.

                    If your drawing is to Y14.5-1994 or Y14.5-2009, then you must use the actual value definition from Y14.5.1-1994.
                    Now Y14.5-2018 is a bit ambiguous about which math standard to use, but the only technical reference is to Y14.5.1-1994.

                    Unless I am missing something, Y14.5 does not point to Y14.5.1-2019 as of yet. Therefore, I guess you should use the actual value definition from Y14.5.1-1994 which is min and max deviation.
                    I know i'm asking a lot, but can you show me in the spec where it states that?
                    Che Guevara is a communist scumbag.

                    Comment


                    • JacobCheverie
                      JacobCheverie commented
                      Editing a comment
                      In Y14.5-2018: Para. 1.1 states "For a mathematical explanation of many of the principles in this Standard, see ASME Y14.5.1M".

                      In Y14.5.1M-1994: Para. 6.5(c) states "For both unilateral and bilateral profile tolerances two actual values are necessarily calculated: one for surface variations in the positive direction and one for the negative direction. For each direction, the actual value of profile is the smallest intermediate tolerance to which the surface conforms. Note that no single actual value may be calculated for comparison to the tolerance value in the feature control frame, except in the case of unilateral profile tolerances."

                  Related Topics

                  Collapse

                  Working...
                  X