Position measurement using GD&T callout VS a Distance Dimension

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

  • Position measurement using GD&T callout VS a Distance Dimension

    Good Afternoon,
    I have an issue where I am building out a part that has an ABC datum structure when I set up a hole position measurement using the GD&T on the drawing and run the program it shows the holes as deviating in the range of 0.005" to 0.009" depending on the hole. When I dimension the part using the distance measurement and the same datum plane with the same circle it measures pretty near nominal. When I physically measure the part it comes up the same as the distance measurement within my routine. I'm using 2019 R1 with a Romer Arm 7525 6 axis, Perpendicular to centerline is on, use datum structure is on, and my alignment and my datum alignment line up.
    Thanks for any help,
    Richard

  • #2
    I'm using a CAD model as well

    Comment


    • Schlag
      Schlag commented
      Editing a comment
      If you are using LEGACY, the USE DATUMS checkbox does not do what you think its supposed to. Uncheck it. What is your distance doing ??? So many ways to use this.. // to AXIS, perp to feature ? So many possibilities. Are you checking the feature and dimensioning it in the same alignment ? Post some code

  • #3
    Distance dimensions currently line up with physical measurements.

    Comment


    • #4
      I apologize, this is also done using Xactmeasure

      Comment


      • #5
        It would be more understandable if you can copy the code and post in the reply section. it will post the code as you see on pc-dmis screen. right now the word file is creating it in broken sections and hard to understand. also please post the code from the command mode instead of summery mode.

        Comment


        • aliptpatel
          aliptpatel commented
          Editing a comment
          also paste the results of dimensional measurement as well as true positions you get.

        • Richardbeyer87
          Richardbeyer87 commented
          Editing a comment
          I fixed the code posting, I blanked out my current report on accident, however the distances were varying by approx 0.010" from each other. The distance dimension was done in 3D from cylinder to plane (Datum) and was approximately nominal which is how it turned out with a height stand and pin gage. The position was throwing a +0.010" deviation and showing OOT.

      • #6
        STARTUP =ALIGNMENT/START,RECALL:USE_PART_SETUP,LIST=YES
        ALIGNMENT/END
        MODE/MANUAL
        FORMAT/TEXT,OPTIONS, ,HEADINGS,SYMBOLS, ;NOM,TOL,MEAS,DEV,OUTTOL, ,
        LOADPROBE/6MM_RUBY
        TIP/TIP1, SHANKIJK=0, 0, 1, ANGLE=0
        PLN1 =FEAT/PLANE,CARTESIAN,OUTLINE
        THEO/<0.7702,-0.4949,9.7087>,<0,0,-1>
        ACTL/<11.0759,-15.3892,3.6348>,<-0.0018293,-0.0002399,0.9999983>
        MEAS/PLANE,21

        ENDMEAS/
        A1 =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
        ALIGNMENT/LEVEL,ZPLUS,PLN1
        ALIGNMENT/TRANS,ZAXIS,PLN1
        ALIGNMENT/END
        LIN1 =FEAT/LINE,CARTESIAN,UNBOUNDED
        THEO/<4.7491,0.0767,0>,<0,1,0>
        ACTL/<11.8033,-10.9741,0>,<-0.999249,0.0387473,0>
        MEAS/LINE,3,FEATURE=PLN1
        HIT/BASIC,NORMAL,<4.7491,0.0767,-0.2794>,<1,0,0>,<11.8033,-10.9741,-0.2015>,USE THEO=YES
        HIT/BASIC,NORMAL,<4.7491,0.5866,-0.3486>,<1,0,0>,<11.2372,-10.9522,-0.2151>,USE THEO=YES
        HIT/BASIC,NORMAL,<4.7491,1.2857,-0.3513>,<1,0,0>,<10.7409,-10.9329,-0.2322>,USE THEO=YES
        ENDMEAS/
        LIN2 =FEAT/LINE,CARTESIAN,UNBOUNDED
        THEO/<-2.7205,1.4739,0>,<1,0,0>
        ACTL/<10.2131,-18.43,0>,<0.0379602,0.9992793,0>
        MEAS/LINE,5,FEATURE=PLN1
        HIT/BASIC,NORMAL,<-2.7205,1.4739,-0.3123>,<0,1,0>,<10.2125,-18.43,-0.2118>,USE THEO=YES
        HIT/BASIC,NORMAL,<-1.2182,1.4739,-0.27>,<0,1,0>,<10.2991,-16.1765,-0.28>,USE THEO=YES
        HIT/BASIC,NORMAL,<0.7345,1.4739,-0.2809>,<0,1,0>,<10.3301,-15.3708,-0.1813>,USE THEO=YES
        HIT/BASIC,NORMAL,<3.0449,1.4739,-0.2378>,<0,1,0>,<10.4882,-11.1894,-0.1606>,USE THEO=YES
        HIT/BASIC,NORMAL,<4.5504,1.4739,-0.3196>,<0,1,0>,<10.448,-12.2318,-0.1574>,USE THEO=YES
        ENDMEAS/
        PNT1 =FEAT/POINT,CARTESIAN,NO
        THEO/<4.7491,1.4739,0>,<0,1,0>
        ACTL/<10.4983,-10.9235,0>,<-0.999249,0.0387473,0>
        CONSTR/POINT,INT,LIN1,LIN2
        A2 =ALIGNMENT/START,RECALL:A1,LIST=YES
        ALIGNMENT/ROTATE,XPLUS,TO,LIN2,ABOUT,ZPLUS
        ALIGNMENT/TRANS,XAXIS,PNT1
        ALIGNMENT/TRANS,YAXIS,PNT1
        ALIGNMENT/END
        PLN2 =FEAT/PLANE,CARTESIAN,OUTLINE
        THEO/<-11.2087,-3.3107,-0.2484>,<-1,0,0>
        ACTL/<-11.2085,-3.2537,-0.2702>,<-0.9999974,-0.0000508,0.0022694>
        MEAS/PLANE,11
        HIT/BASIC,NORMAL,D=-0.0001,<-11.2087,-3.4094,0.5019>,<-1,0,0>,<-11.2068,-3.3849,0.4695>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0001,<-11.2087,-3.0568,0.5558>,<-1,0,0>,<-11.207,-3.1821,0.3793>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0001,<-11.2087,-3.1073,-1.3462>,<-1,0,0>,<-11.2088,-3.1597,-0.3381>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0,<-11.2087,-3.4966,-1.3343>,<-1,0,0>,<-11.2087,-3.3794,-0.3732>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0001,<-11.2087,-3.4875,0.5695>,<-1,0,0>,<-11.2104,-3.3538,-1.0721>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0003,<-11.2087,-3.1758,0.1906>,<-1,0,0>,<-11.21,-3.0909,-1.0393>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0001,<-11.2087,-3.312,-0.9382>,<-1,0,0>,<-11.2092,-3.3164,-0.6351>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0,<-11.2087,-3.4148,-0.637>,<-1,0,0>,<-11.2085,-3.2617,-0.2331>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0002,<-11.2087,-3.2154,-0.4623>,<-1,0,0>,<-11.2069,-3.2486,0.3449>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0002,<-11.2087,-3.3971,-0.0908>,<-1,0,0>,<-11.2084,-3.1075,-0.1249>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0002,<-11.2087,-3.3452,0.2587>,<-1,0,0>,<-11.2089,-3.3055,-0.3503>,USE THEO=YES
        ENDMEAS/
        PLN3 =FEAT/PLANE,CARTESIAN,OUTLINE
        THEO/<-10.3939,-3.5356,-0.4616>,<0,-1,0>
        ACTL/<-10.5564,-3.5284,-0.2983>,<-0.0000351,-0.9999998,-0.0006949>
        MEAS/PLANE,13
        HIT/BASIC,NORMAL,D=0.0002,<-9.6345,-3.5356,-0.6194>,<0,-1,0>,<-9.731,-3.5282,-0.8116>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0,<-9.6938,-3.5356,-1.3409>,<0,-1,0>,<-9.6742,-3.5278,-1.1156>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0001,<-11.1178,-3.5356,-1.2858>,<0,-1,0>,<-11.0088,-3.5276,-1.1899>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0001,<-11.1299,-3.5356,0.527>,<0,-1,0>,<-11.0326,-3.5284,-0.3214>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0002,<-10.3082,-3.5356,0.5355>,<0,-1,0>,<-10.4566,-3.5282,-0.3944>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0,<-10.6002,-3.5356,-0.2487>,<0,-1,0>,<-10.4703,-3.528,-0.9101>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0002,<-10.4918,-3.5356,0.3345>,<0,-1,0>,<-10.4241,-3.5287,0.4116>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0002,<-9.7935,-3.5356,-1.068>,<0,-1,0>,<-11.0693,-3.5291,0.4894>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0001,<-10.4044,-3.5356,-0.6987>,<0,-1,0>,<-10.4649,-3.529,0.4435>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0.0002,<-10.9245,-3.5356,-0.5044>,<0,-1,0>,<-10.5545,-3.5286,-0.3441>,USE THEO=YES
        HIT/BASIC,NORMAL,D=0,<-10.8409,-3.5356,0.3071>,<0,-1,0>,<-11.102,-3.5284,-0.3154>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0002,<-10.1893,-3.5356,-1.0917>,<0,-1,0>,<-10.6201,-3.5283,-0.0821>,USE THEO=YES
        HIT/BASIC,NORMAL,D=-0.0001,<-9.9922,-3.5356,-0.8479>,<0,-1,0>,<-10.6247,-3.5287,0.2616>,USE THEO=YES
        ENDMEAS/
        DATDEF/FEATURE=PLN1,A
        DATDEF/FEATURE=PLN2,B
        DATDEF/FEATURE=PLN3,C
        CYL1 =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
        THEO/<-6.8291,-0.75,0>,<0,0,1>,0.419,0.5354
        ACTL/<-6.8285,-0.7346,0>,<-0.0026633,0.0006093,0.9999963>,0.42,0.5354
        TARG/<-6.8291,-0.75,0>,<0,0,1>
        START ANG=0,END ANG=360
        ANGLE VEC=<-1,0,0>
        DIRECTION=CCW
        SHOW FEATURE PARAMETERS=NO
        SHOW CONTACT PARAMETERS=YES
        NUMHITS=3,NUMLEVELS=3,DEPTH=0,END OFFSET=0,PITCH=0
        SAMPLE METHOD=SAMPLE_HITS
        SAMPLE HITS=0,SPACER=0
        FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
        SHOW HITS=NO
        CYL2 =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,MAX_INSC
        THEO/<-5.8291,-0.75,-0.5354>,<0,0,1>,0.419,-0.5354
        ACTL/<-5.8285,-0.7348,-0.5354>,<0.0011902,0.0004299,0.9999992>,0.4201,-0.5354
        TARG/<-5.8291,-0.75,-0.5354>,<0,0,1>
        START ANG=0,END ANG=360
        ANGLE VEC=<-1,0,0>
        DIRECTION=CCW
        SHOW FEATURE PARAMETERS=NO
        SHOW CONTACT PARAMETERS=YES
        NUMHITS=3,NUMLEVELS=3,DEPTH=0,END OFFSET=0,PITCH=0
        SAMPLE METHOD=SAMPLE_HITS
        SAMPLE HITS=0,SPACER=0
        FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
        SHOW HITS=NO

        FCFLOC1 =POSITION : CYL1,CYL2,CYL3,...
        FEATCTRLFRAME/SHOWNOMS=NOSHOWPARAMS=YES,SHOWEXPANDED=YES
        CADGRAPH=OFF,REPORTGRAPH=OFF,TEXT=OFF,MULT=10.00,A RROWDENSITY=100,OUTPUT=BOTH,UNITS=IN
        COMPOSITE=NO,FIT TO DATUMS=YES,DEV PERPEN CENTERLINE=ON,OUTPUT ALIGNMENT=Datum Reference Frame
        CUSTOMIZED DRF=NO
        STANDARDTYPE=ASME_Y14_5
        SIZE TOLERANCES/7DIAMETER,0.413,0.009,0
        PRIMARY DIMENSION/POSITION,DIAMETER,0.02,MMC,<PZ>,<len>,A,B,C
        SECONDARY DIMENSION/POSITION,DIAMETER,0.012,<MC>,<PZ>,<len>,A,<dat>,<d at>
        NOTE/FCFLOC1
        FEATURES/CYL1,CYL2,CYL3,CYL4,CYL5,CYL6,CYL7,,
        DIM DIST1= 2D DISTANCE FROM CYLINDER CYL1 TO PLANE PLN3 PAR TO YAXIS,NO_RADIUS UNITS=IN,$
        GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
        AX NOMINAL +TOL -TOL MEAS DEV OUTTOL
        M 2.7856 0.0390 0.0390 2.7938 0.0082 0.0000 -----#---
        DIM DIST3= 3D DISTANCE FROM CYLINDER CYL1 TO PLANE PLN3,SHORTEST=OFF,NO_RADIUS UNITS=IN,$
        GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
        AX NOMINAL +TOL -TOL MEAS DEV OUTTOL
        M 2.7856 0.0390 0.0390 2.7941 0.0086 0.0000 -----#---
        FCFLOC2 =POSITION : CYL1
        FEATCTRLFRAME/SHOWNOMS=NOSHOWPARAMS=YES,SHOWEXPANDED=YES
        CADGRAPH=OFF,REPORTGRAPH=OFF,TEXT=OFF,MULT=10.00,A RROWDENSITY=100,OUTPUT=BOTH,UNITS=IN
        COMPOSITE=NO,FIT TO DATUMS=YES,DEV PERPEN CENTERLINE=ON,OUTPUT ALIGNMENT=Datum Reference Frame
        CUSTOMIZED DRF=NO
        STANDARDTYPE=ASME_Y14_5
        SIZE TOLERANCES/1DIAMETER,0.419,0.009,0
        PRIMARY DIMENSION/POSITION,DIAMETER,0.02,MMC,<PZ>,<len>,A,B,C
        SECONDARY DIMENSION/,0.012,<MC>,<dat>,<dat>,<dat>
        NOTE/FCFLOC2
        FEATURES/CYL1,,
        A3 =ALIGNMENT/START,RECALL:A2,LIST=YES
        ALIGNMENT/LEVEL,ZPLUS,PLN1
        ALIGNMENT/TRANS,ZAXIS,PLN1
        ALIGNMENT/ROTATE,XPLUS,TO,PLN2,ABOUT,ZPLUS
        ALIGNMENT/TRANS,XAXIS,PLN2
        ALIGNMENT/TRANS,YAXIS,PLN3
        ALIGNMENT/END
        DIM LOC1= POSITION OF CYLINDER CYL1 USE AXIS=AVERAGE REF LENGTH=0.0000 UNITS=IN ,$
        GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH FIT TO DATUMS=OFF DEV PERPEN CENTERLINE=ON DISPLAY=DIAMETER
        AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL
        X -4.3795 -4.3809 -0.0014
        Y -2.7856 -2.7934 -0.0079
        DF 0.4190 0.0260 0.0260 0.4200 0.0010 0.0000 ----#----
        TP RFS 0.0260 0.0000 0.0160 0.0160 0.0000 -----#---
        END OF DIMENSION LOC1

        Comment


        • #7
          I got rid of a few of the cylinders as they were all taken the same way and i could not copy and paste 10,500 words

          Comment


          • #8
            After you define your 3 Datums. Create a new alignment with those 3 datums. PLN 1 is primary. When you do distance you are doing shortest distance to PLN 3. So your measurement is PERP or // to your datum C. Well...... your postional callout is using A as the primary. CMM and GD&T are 100% 3-D spatial relations. When plane 1 and 3 are out of sq. to each other this may be the difference you are seeing. You are comparing apples to oranges.

            Comment


            • #9
              Im going to play with a new program to test this out, the explanation makes sense if I am understanding correctly when I am creating the dimension distance it is off my original alignment and comparing that to the new position alignment is comparing apples to oranges? Thank you so much for the response I have a direction to head into now.

              Comment


              • Schlag
                Schlag commented
                Editing a comment
                NO. DISTANCE is a dimension and alignment in 1. Notice how your distances are measuring different. 1 is // to Y wich since you are rotated to plane 2 . this distance is really PERP from plane 2 and the second is shortest dist. to pln 3. SO really perp to PLN 3 ( I didnt look at vectors of cylinders so I am guessing on a few // and perp ) I would see what the PERP of B and C is to A as a reference. Distance is the hardest concept to get right. So many possibilitites. you will make of break a measurement routine doing this incorrectly. 3D SPATIAL RELATIONS. Wehn doing distance you have to know what you want to be // to or PERP to. This can effect the outcome so drasticailly.
                Last edited by Schlag; 09-25-2019, 01:08 PM.

              • Richardbeyer87
                Richardbeyer87 commented
                Editing a comment
                I think (hope) Im following here, within my distance dimensions I can control what feature Im measuring perpendicular or parallel to, thus calling it an alignment and dimension in one. I guess my one question is how do I control that within the position Xactmeasure it seems once you put the datum structure and nominals in the software kind of takes over at that point, is there something Im missing? (I cant upload prints but this part has an odd location for datums and knowing our machinists B and C most likely arent perpendicular to A) I have a few tried and true programs on simpler parts that I measure using position and they always line up with an actual physical measurement. Again thank you for your patience and help.
                Richard

            • #10
              I really like this illustration of "distance in reality" (and that is only 2D - 3D adds volumes of alternatives more):

              dist_reality.PNG
              Last edited by AndersI; 09-26-2019, 03:30 AM.
              AndersI
              SW support - Hexagon Metrology Nordic AB

              Comment


              • Richardbeyer87
                Richardbeyer87 commented
                Editing a comment
                I mean it makes sense looking at the picture, not always so easy making the arm do what i want it to.

            Related Topics

            Collapse

            Working...
            X