Alignment strategy

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  • Alignment strategy

    Hello All
    I received one part to measure in CMM with PCDMIS platform, and I am bit confused to alignment strategy on this.
    Attached drawing snap for your understanding

    Here Datum A is bottom face, Datum B represented to 4 holes.
    In program I followed by below steps

    The part is in XY plane
    • Measure datum A
    • Measure 4 holes
    • Connect holes 1 & 4 with Line 1
    • Connect holes 2 & 3 with Line 2
    • Intersect Line 1 & 2 and get a IntPoint
    • Construct MidPoint between holes 2 & 4
    Alignment:
    • Datum A - Spatial alignment in Z
    • MidPoint - Planar alignment in X
    • IntPnt - Origin XY

    My concern,
    • Is my alignment strategy is correct? please suggest
    • How we can apply MMC to B datum?

    I need help on this please

    Thanks












    Attached Files

  • #2
    You need to use XactmMeasure dimensioning. Measure datum A as a plane and define it as datum A. Then measure the four datum B holes as cylinders, construct a feature set from them and define the set as datum B. Dimension the four holes in one XactMeasure position command. Measure datum C as a cylinder. Dimension datum C to datums A & B. Example code below...

    Comment


    • #3
      Code:
      Code:
      pln1 =feat/contact/plane/default,cartesian,outline,least_sqr
      theo/<95,47.5,0>,<0,0,-1>
      actl/<95,47.5,0>,<0,0,-1>
      targ/<95,47.5,0>,<0,0,-1>
      angle vec=<-0.0079997,0,0.999968>,square
      show feature parameters=yes
      void detection=no
      surface=thickness_none,0
      measure mode=nominals
      rmeas=none,none,none
      auto wrist=no
      circular moves=straight
      graphical analysis=no
      feature locator=no,no,""
      show contact parameters=yes
      numhits=3,numrows=2
      spacer=95
      show hits=yes
      hit/basic,<190,0,0>,<0,0,-1>,<190,0,0>
      hit/basic,<95,0,0>,<0,0,-1>,<95,0,0>
      hit/basic,<0,0,0>,<0,0,-1>,<0,0,0>
      hit/basic,<0,95,0>,<0,0,-1>,<0,95,0>
      hit/basic,<95,95,0>,<0,0,-1>,<95,95,0>
      hit/basic,<190,95,0>,<0,0,-1>,<190,95,0>
      endmeas/
      cyl1 =feat/contact/cylinder/default,cartesian,in,least_sqr
      theo/<20,85,10>,<0,0,1>,12,10
      actl/<20,85,10>,<0,0,1>,12,10
      targ/<20,85,10>,<0,0,1>
      start ang=0,end ang=360
      angle vec=<0,0,1>
      direction=ccw
      show feature parameters=yes
      void detection=yes
      remeasure=no,use theo=no
      surface=thickness_none,0
      measure mode=nominals
      rmeas=none,none,none
      auto wrist=no
      circular moves=straight
      graphical analysis=no
      feature locator=no,no,""
      show contact parameters=yes
      numhits=5,numlevels=3,depth=2,end offset=2,pitch=0
      sample method=sample_hits
      sample hits=0,spacer=0
      find hole=disabled,onerror=no,read pos=no
      show hits=yes
      hit/basic,<26,85,2>,<-1,0,0>,<26,85,2>
      hit/basic,<21.854,90.706,2>,<-0.309017,-0.9510565,0>,<21.854,90.706,2>
      hit/basic,<15.146,88.527,2>,<0.809017,-0.5877853,0>,<15.146,88.527,2>
      hit/basic,<15.146,81.473,2>,<0.809017,0.5877853,0>,<15 .146,81.473,2>
      hit/basic,<21.854,79.294,2>,<-0.309017,0.9510565,0>,<21.854,79.294,2>
      hit/basic,<21.854,79.294,5>,<-0.309017,0.9510565,0>,<21.854,79.294,5>
      hit/basic,<15.146,81.473,5>,<0.809017,0.5877853,0>,<15 .146,81.473,5>
      hit/basic,<15.146,88.527,5>,<0.809017,-0.5877853,0>,<15.146,88.527,5>
      hit/basic,<21.854,90.706,5>,<-0.309017,-0.9510565,0>,<21.854,90.706,5>
      hit/basic,<26,85,5>,<-1,0,0>,<26,85,5>
      hit/basic,<26,85,8>,<-1,0,0>,<26,85,8>
      hit/basic,<21.854,90.706,8>,<-0.309017,-0.9510565,0>,<21.854,90.706,8>
      hit/basic,<15.146,88.527,8>,<0.809017,-0.5877853,0>,<15.146,88.527,8>
      hit/basic,<15.146,81.473,8>,<0.809017,0.5877853,0>,<15 .146,81.473,8>
      hit/basic,<21.854,79.294,8>,<-0.309017,0.9510565,0>,<21.854,79.294,8>
      endmeas/
      cyl2 =feat/contact/cylinder/default,cartesian,in,least_sqr
      theo/<170,85,10>,<0,0,1>,12,10
      actl/<170,85,10>,<0,0,1>,12,10
      targ/<170,85,10>,<0,0,1>
      start ang=0,end ang=360
      angle vec=<0,0,1>
      direction=ccw
      show feature parameters=yes
      void detection=yes
      remeasure=no,use theo=no
      surface=thickness_none,0
      measure mode=nominals
      rmeas=none,none,none
      auto wrist=no
      circular moves=straight
      graphical analysis=no
      feature locator=no,no,""
      show contact parameters=yes
      numhits=5,numlevels=3,depth=2,end offset=2,pitch=0
      sample method=sample_hits
      sample hits=0,spacer=0
      find hole=disabled,onerror=no,read pos=no
      show hits=yes
      hit/basic,<176,85,2>,<-1,0,0>,<176,85,2>
      hit/basic,<171.854,90.706,2>,<-0.309017,-0.9510565,0>,<171.854,90.706,2>
      hit/basic,<165.146,88.527,2>,<0.809017,-0.5877853,0>,<165.146,88.527,2>
      hit/basic,<165.146,81.473,2>,<0.809017,0.5877853,0>,<1 65.146,81.473,2>
      hit/basic,<171.854,79.294,2>,<-0.309017,0.9510565,0>,<171.854,79.294,2>
      hit/basic,<171.854,79.294,5>,<-0.309017,0.9510565,0>,<171.854,79.294,5>
      hit/basic,<165.146,81.473,5>,<0.809017,0.5877853,0>,<1 65.146,81.473,5>
      hit/basic,<165.146,88.527,5>,<0.809017,-0.5877853,0>,<165.146,88.527,5>
      hit/basic,<171.854,90.706,5>,<-0.309017,-0.9510565,0>,<171.854,90.706,5>
      hit/basic,<176,85,5>,<-1,0,0>,<176,85,5>
      hit/basic,<176,85,8>,<-1,0,0>,<176,85,8>
      hit/basic,<171.854,90.706,8>,<-0.309017,-0.9510565,0>,<171.854,90.706,8>
      hit/basic,<165.146,88.527,8>,<0.809017,-0.5877853,0>,<165.146,88.527,8>
      hit/basic,<165.146,81.473,8>,<0.809017,0.5877853,0>,<1 65.146,81.473,8>
      hit/basic,<171.854,79.294,8>,<-0.309017,0.9510565,0>,<171.854,79.294,8>
      endmeas/
      cyl3 =feat/contact/cylinder/default,cartesian,in,least_sqr
      theo/<20,10,10>,<0,0,1>,12,10
      actl/<20,10,10>,<0,0,1>,12,10
      targ/<20,10,10>,<0,0,1>
      start ang=0,end ang=360
      angle vec=<0,0,1>
      direction=ccw
      show feature parameters=yes
      void detection=yes
      remeasure=no,use theo=no
      surface=thickness_none,0
      measure mode=nominals
      rmeas=none,none,none
      auto wrist=no
      circular moves=straight
      graphical analysis=no
      feature locator=no,no,""
      show contact parameters=yes
      numhits=5,numlevels=3,depth=2,end offset=2,pitch=0
      sample method=sample_hits
      sample hits=0,spacer=0
      find hole=disabled,onerror=no,read pos=no
      show hits=yes
      hit/basic,<26,10,2>,<-1,0,0>,<26,10,2>
      hit/basic,<21.854,15.706,2>,<-0.309017,-0.9510565,0>,<21.854,15.706,2>
      hit/basic,<15.146,13.527,2>,<0.809017,-0.5877853,0>,<15.146,13.527,2>
      hit/basic,<15.146,6.473,2>,<0.809017,0.5877853,0>,<15. 146,6.473,2>
      hit/basic,<21.854,4.294,2>,<-0.309017,0.9510565,0>,<21.854,4.294,2>
      hit/basic,<21.854,4.294,5>,<-0.309017,0.9510565,0>,<21.854,4.294,5>
      hit/basic,<15.146,6.473,5>,<0.809017,0.5877853,0>,<15. 146,6.473,5>
      hit/basic,<15.146,13.527,5>,<0.809017,-0.5877853,0>,<15.146,13.527,5>
      hit/basic,<21.854,15.706,5>,<-0.309017,-0.9510565,0>,<21.854,15.706,5>
      hit/basic,<26,10,5>,<-1,0,0>,<26,10,5>
      hit/basic,<26,10,8>,<-1,0,0>,<26,10,8>
      hit/basic,<21.854,15.706,8>,<-0.309017,-0.9510565,0>,<21.854,15.706,8>
      hit/basic,<15.146,13.527,8>,<0.809017,-0.5877853,0>,<15.146,13.527,8>
      hit/basic,<15.146,6.473,8>,<0.809017,0.5877853,0>,<15. 146,6.473,8>
      hit/basic,<21.854,4.294,8>,<-0.309017,0.9510565,0>,<21.854,4.294,8>
      endmeas/
      cyl4 =feat/contact/cylinder/default,cartesian,in,least_sqr
      theo/<170,10,10>,<0,0,1>,12,10
      actl/<170,10,10>,<0,0,1>,12,10
      targ/<170,10,10>,<0,0,1>
      start ang=0,end ang=360
      angle vec=<0,0,1>
      direction=ccw
      show feature parameters=yes
      void detection=yes
      remeasure=no,use theo=no
      surface=thickness_none,0
      measure mode=nominals
      rmeas=none,none,none
      auto wrist=no
      circular moves=straight
      graphical analysis=no
      feature locator=no,no,""
      show contact parameters=yes
      numhits=5,numlevels=3,depth=2,end offset=2,pitch=0
      sample method=sample_hits
      sample hits=0,spacer=0
      find hole=disabled,onerror=no,read pos=no
      show hits=yes
      hit/basic,<176,10,2>,<-1,0,0>,<176,10,2>
      hit/basic,<171.854,15.706,2>,<-0.309017,-0.9510565,0>,<171.854,15.706,2>
      hit/basic,<165.146,13.527,2>,<0.809017,-0.5877853,0>,<165.146,13.527,2>
      hit/basic,<165.146,6.473,2>,<0.809017,0.5877853,0>,<16 5.146,6.473,2>
      hit/basic,<171.854,4.294,2>,<-0.309017,0.9510565,0>,<171.854,4.294,2>
      hit/basic,<171.854,4.294,5>,<-0.309017,0.9510565,0>,<171.854,4.294,5>
      hit/basic,<165.146,6.473,5>,<0.809017,0.5877853,0>,<16 5.146,6.473,5>
      hit/basic,<165.146,13.527,5>,<0.809017,-0.5877853,0>,<165.146,13.527,5>
      hit/basic,<171.854,15.706,5>,<-0.309017,-0.9510565,0>,<171.854,15.706,5>
      hit/basic,<176,10,5>,<-1,0,0>,<176,10,5>
      hit/basic,<176,10,8>,<-1,0,0>,<176,10,8>
      hit/basic,<171.854,15.706,8>,<-0.309017,-0.9510565,0>,<171.854,15.706,8>
      hit/basic,<165.146,13.527,8>,<0.809017,-0.5877853,0>,<165.146,13.527,8>
      hit/basic,<165.146,6.473,8>,<0.809017,0.5877853,0>,<16 5.146,6.473,8>
      hit/basic,<171.854,4.294,8>,<-0.309017,0.9510565,0>,<171.854,4.294,8>
      endmeas/
      group_of_holes=feat/set,cartesian
      theo/<95,47.5,10>,<0,0,1>
      actl/<95,47.5,10>,<0,0,1>
      constr/set,basic,cyl1,cyl2,cyl3,cyl4,,
      datdef/a,features=pln1,,
      datdef/b,features=group_of_holes,,
      cyl5 =feat/contact/cylinder/default,cartesian,in,least_sqr
      theo/<95,47.5,45>,<0,0,1>,10,10
      actl/<95,47.5,45>,<0,0,1>,10,10
      targ/<95,47.5,45>,<0,0,1>
      start ang=0,end ang=360
      angle vec=<0,0,1>
      direction=ccw
      show feature parameters=yes
      void detection=yes
      remeasure=no,use theo=no
      surface=thickness_none,0
      measure mode=nominals
      rmeas=none,none,none
      auto wrist=no
      circular moves=straight
      graphical analysis=no
      feature locator=no,no,""
      show contact parameters=yes
      numhits=5,numlevels=3,depth=2,end offset=2,pitch=0
      sample method=sample_hits
      sample hits=0,spacer=0
      find hole=disabled,onerror=no,read pos=no
      show hits=yes
      hit/basic,<100,47.5,37>,<-1,0,0>,<100,47.5,37>
      hit/basic,<96.545,52.255,37>,<-0.309017,-0.9510565,0>,<96.545,52.255,37>
      hit/basic,<90.955,50.439,37>,<0.809017,-0.5877853,0>,<90.955,50.439,37>
      hit/basic,<90.955,44.561,37>,<0.809017,0.5877853,0>,<9 0.955,44.561,37>
      hit/basic,<96.545,42.745,37>,<-0.309017,0.9510565,0>,<96.545,42.745,37>
      hit/basic,<96.545,42.745,40>,<-0.309017,0.9510565,0>,<96.545,42.745,40>
      hit/basic,<90.955,44.561,40>,<0.809017,0.5877853,0>,<9 0.955,44.561,40>
      hit/basic,<90.955,50.439,40>,<0.809017,-0.5877853,0>,<90.955,50.439,40>
      hit/basic,<96.545,52.255,40>,<-0.309017,-0.9510565,0>,<96.545,52.255,40>
      hit/basic,<100,47.5,40>,<-1,0,0>,<100,47.5,40>
      hit/basic,<100,47.5,43>,<-1,0,0>,<100,47.5,43>
      hit/basic,<96.545,52.255,43>,<-0.309017,-0.9510565,0>,<96.545,52.255,43>
      hit/basic,<90.955,50.439,43>,<0.809017,-0.5877853,0>,<90.955,50.439,43>
      hit/basic,<90.955,44.561,43>,<0.809017,0.5877853,0>,<9 0.955,44.561,43>
      hit/basic,<96.545,42.745,43>,<-0.309017,0.9510565,0>,<96.545,42.745,43>
      endmeas/

      Comment


      • #4
        Code:
        FCFLOC1 =POSITION : CYL1,CYL2,CYL3,...
        FEATCTRLFRAME/SHOWNOMS=YES,SHOWPARAMS=YES,SHOWEXPANDED=YES,
        CADGRAPH=OFF,REPORTGRAPH=OFF,TEXT=OFF,MULT=10.00,A RROWDENSITY=100,OUTPUT=BOTH,UNITS=MM,
        COMPOSITE=NO,FIT TO DATUMS=YES,DEV PERPEN CENTERLINE=ON,OUTPUT ALIGNMENT=Datum Reference Frame
        CUSTOMIZED DRF=NO
        STANDARDTYPE=ASME_Y14_5
        SIZE TOLERANCES/4,DIAMETER,12,0.11,-0.11
        PRIMARY DIMENSION/POSITION,DIAMETER,0.05,<MC>,<PZ>,<len>,A,<dat>,<da t>
        SECONDARY DIMENSION/,<tol>,<MC>,<dat>,<dat>,<dat>
        NOTE/FCFLOC1
        FEATURES/CYL1,CYL2,CYL3,CYL4,,
        Set
        <NEW>
        CYL1
        X:NOM=20
        Y:NOM=85
        <NEW>
        CYL2
        X:NOM=170
        Y:NOM=85
        <NEW>
        CYL3
        X:NOM=20
        Y:NOM=10
        <NEW>
        CYL4
        X:NOM=170
        Y:NOM=10
        <NEW>
        FCFLOC2 =POSITION : CYL5
        FEATCTRLFRAME/SHOWNOMS=YES,SHOWPARAMS=YES,SHOWEXPANDED=YES,
        CADGRAPH=OFF,REPORTGRAPH=OFF,TEXT=OFF,MULT=10.00,A RROWDENSITY=100,OUTPUT=BOTH,UNITS=MM,
        COMPOSITE=NO,FIT TO DATUMS=YES,DEV PERPEN CENTERLINE=ON,OUTPUT ALIGNMENT=Datum Reference Frame
        CUSTOMIZED DRF=NO
        STANDARDTYPE=ASME_Y14_5
        SIZE TOLERANCES/1,DIAMETER,10,0.15,-0.15
        PRIMARY DIMENSION/POSITION,DIAMETER,0.2,MMC,<PZ>,<len>,A,B,MMC,<size >,<dat>
        SECONDARY DIMENSION/,<tol>,<MC>,<dat>,<dat>,<dat>
        NOTE/FCFLOC2
        FEATURES/CYL5,,
        CYL5
        X:NOM=0
        Y:NOM=0
        <NEW>
        DATUMS
        D2:NOM=12,+TOL=0.11,-TOL=-0.11

        Comment


        • #5
          Thanks Neil,
          I understand the codes and let me share few clarifications

          Now we are setting plane A as Datum A and 4 holes set as Datum B, is the spatial alignment and origin to B not required as we are doing 3-2-1?

          Location of B holes you referenced to corner of datum face A, any reason please?

          Since this type scenario I came across first time, I need to understand clearly this strategy

          Thanks
          vAp









          Comment


          • #6
            XactMeasure dimensioning works independently from the current alignment. PC-Dmis creates an alignment internally that satisfies the datum reference frame you specify within the command. However, if you did want to construct the alignment in PC-Dmis yourself you would Level to datum A (spatial alignment) and then perform a 2D bestfit on the four datum B cylinders allowing rotation and translation.

            Comment


            • #7
              Its clear now Neil, well appreciated


              Thanks

              Comment

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