Extracting Theoretical Points from a Cone?

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  • Extracting Theoretical Points from a Cone?

    On my drawing I have specific points called out on a cone's surface at it's center line. I would just measure the individual points but out of 7 points 1 is at the very top, 1 is at the very bottom, and 1 is off the part entirely. I made 7 offset planes and I'm trying to construct points with the offset planes and the cone but nearly every way puts the point in the center instead of on the surface of the cone. What can I do to properly inspect these points?
    I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

  • #2
    You could...

    1) measure the cone
    2) construct generic lines that touch the cone at the correct height or radial value AND that do so at the correct vector
    3) construct point at int of cone and each line
    4) dimension the point

    If you show us a snippet of your drawing we'll be able to totally understand your situation and then offer you a higher level of help.
    SF7107(PCD), SF454(PCD), 152614(Quindos), 9159(Quindos), 7107(Quindos), B&S Manual, M&M Gear Checker

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    • #3
      Construct circles at the intersect of the cone and planes. Create an offset point at the coordinate specified. Create a line from the circle to the offset pint. Construct a point by piercing the cone with the line.
      sigpicHave a homebrew

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      • #4
        cone_points.PNG
        I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

        Comment


        • #5
          Something weird happened. When I first constructed the final points, they were in generally the right area. I reran my program (the only thing I changed was the measurement strategy of the cone to default from adaptive concentric circle scan) now all the points are on the opposite side of the cone. I went thru and checked my vectors and nothing seems out of place. I tried changing the order I picked the cone and lines for my pierce point construction. What do you think I'm doing wrong?

          pierce_points.PNG
          I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

          Comment


          • #6
            Make a reverse line from the lines you generated, pierce the cone with those instead.
            sigpicHave a homebrew

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            • #7
              Something's not adding up. When I construct my circles at the right height, the diameter nominal is way bigger than it should be. When I construct my circles using the right diameter, the nominal height is way off. I made auto vector points typing in the coordinates (only points 3-6) given by the chart, they come out pretty close.
              Code:
              CIR_PNT3 =FEAT/CIRCLE,CARTESIAN,IN,NO
              THEO/<0,0,0.835>,<0,0,-1>,34.1566
              ACTL/<0.0011,0.0037,0.833>,<0.0002681,0.0009136,-0.9999995>,34.1566
              CONSTR/CIRCLE,CONE,CON1,HEIGHT,-4,REF_POINT = ORIGIN,REF_VECTOR = WORKPLANE
              CIR_PNT4 =FEAT/CIRCLE,CARTESIAN,IN,NO
              THEO/<0,0,1.835>,<0,0,-1>,33.2385
              ACTL/<0.0008,0.0027,1.833>,<0.0002681,0.0009136,-0.9999995>,33.2196
              CONSTR/CIRCLE,CONE,CON1,HEIGHT,-3,REF_POINT = ORIGIN,REF_VECTOR = WORKPLANE
              CIR_PNT5 =FEAT/CIRCLE,CARTESIAN,IN,NO
              THEO/<0,0,2.835>,<0,0,-1>,32.3205
              ACTL/<0.0005,0.0018,2.833>,<0.0002681,0.0009136,-0.9999995>,32.2826
              CONSTR/CIRCLE,CONE,CON1,HEIGHT,-2,REF_POINT = ORIGIN,REF_VECTOR = WORKPLANE
              CIR_PNT6 =FEAT/CIRCLE,CARTESIAN,IN,NO
              THEO/<0,0,3.835>,<0,0,-1>,31.4025
              ACTL/<0.0003,0.0009,3.833>,<0.0002681,0.0009136,-0.9999995>,31.3455
              CONSTR/CIRCLE,CONE,CON1,HEIGHT,-1,REF_POINT = ORIGIN,REF_VECTOR = WORKPLANE
              point_chart.PNG
              Last edited by S_Cliff; 03-22-2021, 02:41 PM.
              I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

              Comment


              • S_Cliff
                S_Cliff commented
                Editing a comment
                Ok I changed the construction to cone_start and cone_vector and the nominals didn't change. I tried constructing the circles as intersection circles of the cone and offset planes at the correct height and the nominals are the same.

              • UKCMM
                UKCMM commented
                Editing a comment
                Why not do as the drawing states and use datum E with the offset set at .835 from the Origin, the print is not asking you to set an offset from the cone start or any other point.

              • S_Cliff
                S_Cliff commented
                Editing a comment
                I created offset planes from E and then constructed intersection circles from the offset planes and my cone. See #9.

            • #8
              Create planes at the correct height. Create the circles at the intersect of the cone with each plane
              sigpicHave a homebrew

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              • #9
                I got the same nominals. I put the auto vector points at the end for comparison.

                Code:
                OFF_PLN1 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,-1.165>,<0,0,-1>
                ACTL/<-0.4208,16.3676,-1.165>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = 1.165
                INT_CIR1 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,-1.165>,<0,0,-1>,35.9926
                ACTL/<0.0016,0.0055,-1.1718>,<0.0002681,0.0009136,-0.9999995>,36.0352
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN1
                OFF_PLN2 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,-0.165>,<0,0,-1>
                ACTL/<-0.4208,16.3672,-0.165>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = 0.165
                INT_CIR2 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,-0.165>,<0,0,-1>,35.0746
                ACTL/<0.0013,0.0046,-0.1718>,<0.0002681,0.0009136,-0.9999995>,35.0981
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN2
                OFF_PLN3 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,0.835>,<0,0,-1>
                ACTL/<-0.4208,16.3668,0.835>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = -0.835
                INT_CIR3 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,0.835>,<0,0,-1>,34.1566
                ACTL/<0.0011,0.0037,0.8282>,<0.0002681,0.0009136,-0.9999995>,34.1611
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN3
                OFF_PLN4 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,1.835>,<0,0,-1>
                ACTL/<-0.4208,16.3664,1.835>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = -1.835
                INT_CIR4 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,1.835>,<0,0,-1>,33.2385
                ACTL/<0.0008,0.0027,1.8282>,<0.0002681,0.0009136,-0.9999995>,33.224
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN4
                OFF_PLN5 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,2.835>,<0,0,-1>
                ACTL/<-0.4208,16.366,2.835>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = -2.835
                INT_CIR5 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,2.835>,<0,0,-1>,32.3205
                ACTL/<0.0005,0.0018,2.8282>,<0.0002681,0.0009136,-0.9999995>,32.287
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN5
                OFF_PLN6 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,3.835>,<0,0,-1>
                ACTL/<-0.4208,16.3655,3.835>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = -3.835
                INT_CIR6 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,3.835>,<0,0,-1>,31.4025
                ACTL/<0.0003,0.0009,3.8282>,<0.0002681,0.0009136,-0.9999995>,31.35
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN6
                OFF_PLN7 =FEAT/PLANE,CARTESIAN,TRIANGLE,NO
                THEO/<-0.5909,16.3734,4.835>,<0,0,-1>
                ACTL/<-0.4208,16.3651,4.835>,<-0.0000024,0.0004133,-0.9999999>
                CONSTR/PLANE,OFFSET
                ID = PLN_E,,
                OFFSET = -4.835
                INT_CIR7 =FEAT/CIRCLE,CARTESIAN,IN,NO
                THEO/<0,0,4.835>,<0,0,-1>,30.4845
                ACTL/<0,0,4.8282>,<0.0002681,0.0009136,-0.9999995>,30.4129
                CONSTR/CIRCLE,INTOF,CON1,OFF_PLN7
                AV_PNT6 =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                THEO/<0,15.692,3.835>,<0,-0.8989281,-0.4380962>
                ACTL/<0,15.6838,3.8308>,<0,-0.8989281,-0.4380962>
                TARG/<0,15.692,3.835>,<0,-0.8989281,-0.4380962>
                SNAP=NO
                SHOW FEATURE PARAMETERS=NO
                SHOW CONTACT PARAMETERS=NO
                AV_PNT5 =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                THEO/<0,16.173,2.835>,<0,-0.9029734,-0.4296965>
                ACTL/<-0.0002,16.1652,2.831>,<0,-0.9029734,-0.4296965>
                TARG/<0,16.173,2.835>,<0,-0.9029734,-0.4296965>
                SNAP=NO
                SHOW FEATURE PARAMETERS=NO
                SHOW CONTACT PARAMETERS=NO
                AV_PNT4 =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                THEO/<0,16.639,1.835>,<0,-0.911655,-0.4109564>
                ACTL/<0,16.6307,1.8308>,<0,-0.911655,-0.4109564>
                TARG/<0,16.639,1.835>,<0,-0.911655,-0.4109564>
                SNAP=NO
                SHOW FEATURE PARAMETERS=NO
                SHOW CONTACT PARAMETERS=NO
                AV_PNT3 =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                THEO/<0,17.073,0.835>,<0,-0.9224157,-0.3861984>
                ACTL/<-0.0002,17.0646,0.8308>,<0,-0.9224157,-0.3861984>
                TARG/<0,17.073,0.835>,<0,-0.9224157,-0.3861984>
                SNAP=NO
                SHOW FEATURE PARAMETERS=NO
                SHOW CONTACT PARAMETERS=NO
                I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

                Comment


                • #10
                  It's odd that the vectors to your vector points are all different. Are you using a CAD model? If so create the cone with model but don't measure it. Use the same methods to get your points using "model" cone and I'd bet your nominal would be what you're expecting.
                  sigpicHave a homebrew

                  Comment


                  • #11
                    I am using a CAD model. I used quick feature to create my cone. I'm beginning to think it's not an exact cone but not really a sphere either. I'll try to create everything without measuring. Also I'm beginning to doubt how I'm reading the print. I originally thought the profile FCF referred to the whole surface. But maybe they just wanted the profile at the center line. I created a scan at the center line, checked it's profile, and it's good. The profile of the cone is way out of tolerance. And it won't let me put a unilateral tolerance on the cone. Am I correct in interpreting it's asking for a unilateral tolerance?

                    cone_points3.PNG
                    I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

                    Comment


                    • Matthew D. Hoedeman
                      Matthew D. Hoedeman commented
                      Editing a comment
                      I don't think so, 0.010" = [0.25mm]. They are just giving you the same tolerance in both units

                    • S_Cliff
                      S_Cliff commented
                      Editing a comment
                      I was referring to the leader lines not the brackets. I cut of my screenshot a little short. There are two arrows, one pointing to the surface and one pointing to the dotted lined inside the surface.

                  • #12
                    I interpret that as unilateral from the target surface "into" the part or the leader would only point to the surface.
                    sigpicHave a homebrew

                    Comment


                    • Matthew D. Hoedeman
                      Matthew D. Hoedeman commented
                      Editing a comment
                      You need one of the signifiers for unequally disposed, and they are both lacking. The [brackets] tell me it is just inch & [metric]. The offset line is NOT part of either (current) standard.

                    • tking
                      tking commented
                      Editing a comment
                      I'll not say the FCF is correct, still I can see the intent on the print is unilateral as drawn.

                  • #13
                    How would I dimension that? Using the dynamic profile modifier? I also went to the project manager. We concluded it's not a true cone so I'm gonna gather point data and compare it to the model and to the datums rather that to the center of the "cone".
                    I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

                    Comment


                    • tking
                      tking commented
                      Editing a comment
                      I'd probably report the T values of the point data with the appropriate +/- tolerances.

                  • #14
                    So the shaped was indeed not a cone. The profile of the auto cone measured around.05. I did a patch scan of the surface and profile measured .0024. I can't dimension all the points on the chart properly but since they're basic I'll just report what I have for them. Thanks for your help everyone!
                    I'm programming on a Global S 15.30.10 with a HP-S-X1H Scanning Probe, and using 2020 R2.

                    Comment

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