Program problems and alignment with only 2 specified datum

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

  • Program problems and alignment with only 2 specified datum

    Hey gals and guys, I've got a new scenario:

    I've got a part that only specifies a 4-way/Datum B/Hole dimension as a datum, a plane around that hole, and a seemingly arbitrary section of the same surface the hole is through as a secondary planar location. Attached picture is a rough, non-identifying depiction.

    Now, I know I can basically just choose another spot to use to rotate, but I also want to make sure the program is easily repeatable.

    Set the part in place, press go, and let it fly on its own.

    One of the faces on the bent tabs specifies an alignment block on the "print" I've been provided with, so I've set the program to measure a line on that feature and I'm aligning as follows:
    2 points taken within A-1 and 1 in the arbitrary plane location on the same surface to level, rotate between L1 and the line measured on the side of the tab, then origin to L1.

    Everything seemed to be fine at first. First two parts measured okay. Third part measured bad. Tried again, removing and resetting part, measured worse.

    Checked for debris on the tip and part, re-measured my tips, part still measures bad.

    Remove and re-set posts and magnets used in part setup. Measure part that previously measured okay. This one also now fails.

    So the questions:

    1. Is my choice of alignment the best option, or should I be going about this differently?
    2. What is the best option here?

    Thanks again.
    example.jpg

  • #2
    2 points for A ? Why 2 for what would be your primary ? What are you doing with those 2 points ? What is a 4-way ... Is it Monday again because this is confusing...
    ....... Post some code...

    Comment


    • #3
      There are 3 total points taken for A. 2 are in A-1, one is in the other seemingly arbitrarily placed plane marked A-2 on the same surface as A-1. I didn't choose the seemingly arbitrary area, it's on what passes for the print I was provided with.

      I'd said I'm using those 2 and the 3rd point to level the alignment.

      I had never heard of a "4-way" prior to my last job, but apparently it's common lingo for some. That's why I also specified it as Datum B, which is what I was previously used to being the feature that played that role. I'm starting to think it might be a Michigan thing.
      Last edited by MUlissi; 07-10-2019, 10:50 AM.

      Comment


      • CodeWarrior
        CodeWarrior commented
        Editing a comment
        https://www.researchgate.net/figure/...e_fig4_3448927

        Is this what you mean by a "4 way hole"? I've never heard that term before. I'm also from Michigan so maybe I'll run into this at some point haha

      • MUlissi
        MUlissi commented
        Editing a comment
        That would be the thing.

        It was never a term that came up in college, or in my previous jobs, but the first two were Japanese owned companies and the last two have been American owned based out of Michigan.

        Took me a moment the first time I heard the term, and my immediate response was 'Oh, you mean Datum B and C.'

    • #4
      Schlag requested code, so here's my alignment code.

      Code:
                  MODE/MANUAL
      MAN A1     =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                  THEO/<2435.389,-43.444,91.1>,<0,0,-1>
                  ACTL/<409.021,-1114.23,-845.299>,<-0.0071393,0.0005619,0.9999744>
                  TARG/<2435.389,-43.444,91.1>,<0,0,-1>
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      MAN A2     =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                  THEO/<2440.819,-32.686,91.1>,<0,0,-1>
                  ACTL/<404.431,-1102.245,-845.339>,<0,0,1>
                  TARG/<2440.819,-32.686,91.1>,<0,0,-1>
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      MAN A3     =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                  THEO/<2418.216,-10.919,91.1>,<0,0,-1>
                  ACTL/<426.308,-1083.434,-845.193>,<0,0,1>
                  TARG/<2418.216,-10.919,91.1>,<0,0,-1>
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      MAN L1     =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
                  THEO/<2435.47,-36.59,91.1>,<0,0,-1>,11
                  ACTL/<409.086,-1107.376,-845.305>,<-0.00306,0.0018288,0.9999936>,11.144
                  TARG/<2435.47,-36.59,91.1>,<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=4,DEPTH=1,PITCH=0
                    SAMPLE METHOD=SAMPLE_HITS
                    SAMPLE HITS=3,SPACER=1
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                    FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
                  SHOW HITS=NO
                  TIP/T1A-90B0, SHANKIJK=0, -1, 0, ANGLE=0
      LIN2       =FEAT/CONTACT/LINE/DEFAULT,CARTESIAN,UNBOUNDED
                  THEO/<2425.041,-62.607,120.1>,<1,0,0>,<0,-0.9986295,-0.052336>,<0,-0.052336,0.9986295>,20
                  ACTL/<423.96,-1132.908,-875.266>,<-0.9999655,0.0082906,0.0004345>,<-0.008302,-0.9985951,-0.0523342>,<0,-0.052336,0.9986295>,29.538
                  TARG/<2425.041,-62.607,120.1>,<1,0,0>,<0,-0.9986295,-0.052336>,<0,-0.052336,0.9986295>
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    NUMHITS=3,DEPTH=2
                    SAMPLE METHOD=SAMPLE_HITS
                    SAMPLE HITS=1,SPACER=0,INDENT1=0,INDENT2=1
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      A1         =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
                    ALIGNMENT/ITERATE
                      PNT TARGET RAD=0.05,START LABEL=,FIXTURE TOL=0.05,ERROR LABEL=
                      MEAS ALL FEAT=NO,LEVEL AXIS=ZAXIS,ROTATE AXIS=XAXIS,ORIGIN AXIS=YAXIS
                    LEVEL=MAN A1,MAN A2,MAN A3,,
                    ROTATE=MAN L1,LIN2,,
                    ORIGIN=MAN L1,,
                  ALIGNMENT/END
                  MODE/DCC
                  MOVE/POINT,NORMAL,<2423.972,28.456,-78.558>
                  TIP/T1A-90B0, SHANKIJK=-0.02, 1, 0.006, ANGLE=179.782
                  MOVE/POINT,NORMAL,<2433.179,-94.114,76.528>
      ROT LN     =FEAT/CONTACT/LINE/DEFAULT,CARTESIAN,UNBOUNDED
                  THEO/<2425.041,-62.607,120.1>,<1,0,0>,<0,-0.9986295,-0.052336>,<0,-0.052336,0.9986295>,20
                  ACTL/<2425.073,-62.318,120.844>,<0.9994101,-0.034296,-0.0017974>,<-0.0343431,-0.9980404,-0.0523051>,<0,-0.052336,0.9986295>,20.013
                  TARG/<2425.041,-62.607,120.1>,<1,0,0>,<0,-0.9986295,-0.052336>,<0,-0.052336,0.9986295>
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    NUMHITS=5,DEPTH=2
                    SAMPLE METHOD=SAMPLE_HITS
                    SAMPLE HITS=1,SPACER=0,INDENT1=0,INDENT2=1
                    AVOIDANCE MOVE=BOTH,DISTANCE=8
                  SHOW HITS=NO
                  MOVE/POINT,NORMAL,<2435.709,-98.736,-55.758>
                  TIP/T1A0B0, SHANKIJK=0.004, 0.006, -1, ANGLE=178.835
      L1         =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
                  THEO/<2435.47,-36.59,91.1>,<0,0,-1>,11
                  ACTL/<2435.102,-36.908,91.119>,<-0.0057656,-0.0004771,-0.9999833>,11.14
                  TARG/<2435.47,-36.59,91.1>,<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=7,DEPTH=1.75,PITCH=0
                    SAMPLE METHOD=SAMPLE_HITS
                    SAMPLE HITS=3,SPACER=2
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                    FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO
                  SHOW HITS=NO
      A_1-1      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                  THEO/<2435.334,-43.372,91.1>,<0,0,-1>
                  ACTL/<2435.053,-43.69,91.142>,<-0.0014868,-0.0027098,-0.9999952>
                  TARG/<2435.334,-43.372,91.1>,<0,0,-1>
                  SNAP=NO
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      A_1-2      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                  THEO/<2440.77,-32.657,91.1>,<0,0,-1>
                  ACTL/<2440.344,-32.907,91.105>,<-0.0014868,-0.0027098,-0.9999952>
                  TARG/<2440.77,-32.657,91.1>,<0,0,-1>
                  SNAP=NO
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      A_1-3      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
                  THEO/<2418.536,-10.798,91.1>,<0,0,-1>
                  ACTL/<2417.821,-11.342,91.08>,<-0.0014868,-0.0027098,-0.9999952>
                  TARG/<2418.536,-10.798,91.1>,<0,0,-1>
                  SNAP=NO
                  SHOW FEATURE PARAMETERS=NO
                  SHOW CONTACT PARAMETERS=YES
                    AVOIDANCE MOVE=BOTH,DISTANCE=10
                  SHOW HITS=NO
      A2         =ALIGNMENT/START,RECALL:A1,LIST=YES
                    ALIGNMENT/ITERATE
                      PNT TARGET RAD=0.05,START LABEL=,FIXTURE TOL=0.05,ERROR LABEL=
                      MEAS ALL FEAT=NO,LEVEL AXIS=ZAXIS,ROTATE AXIS=XAXIS,ORIGIN AXIS=YAXIS
                    LEVEL=A_1-1,A_1-2,A_1-3,,
                    ROTATE=L1,ROT LN,,
                    ORIGIN=L1,,
                  ALIGNMENT/END

      Comment


      • #5
        I may be confused here...but why is an iterative alignment needed here? Couldn't you just do a normal alignment while leveling Z+ and originating Z to the top plane, rotate to a line on whichever side you wanted, and origin X and Y to the circle? What does the print actually callout? FCF? Is A-1 a datum target with specified point locations?

        Comment


        • #6
          Originally posted by SingularitY View Post
          I may be confused here...but why is an iterative alignment needed here? Couldn't you just do a normal alignment while leveling Z+ and originating Z to the top plane, rotate to a line on whichever side you wanted, and origin X and Y to the circle? What does the print actually callout? FCF? Is A-1 a datum target with specified point locations?
          I was thinking much the same.

          Comment


          • #7
            ROTATE=MAN L1,LIN2,, make two Points insteed and rotate to that,, Point and Point,
            Last edited by Michael_Swe; 07-11-2019, 02:25 AM.

            Comment


            • #8
              PCDMIS doesn’t play nice.
              Naming of features,etc

              NO SPACES, NO DASHES, NO SPECIAL CHARACTERS
              A thru Z
              0 thru 9
              The underscore key _

              Examples
              Man_LN1
              Man_A1_1


              B&S CHAMELEON/PCDMIS CAD++ V2011

              There are no bugs, only "UNDOCUMENTED ENHANCEMENTS!"

              sigpic

              Comment


              • Schlag
                Schlag commented
                Editing a comment
                Yes. That is what he is saying. Its just one of those things that you wont know when or how it will bite you or even if it will... No experienced user would condone the use of anything other that what dph51 stated above. Its just one of those things that you don't question or ask why and just understand that many who have gone before you have paid with their blood to pass on this information to you. There are 1000's of posts on this forum talking about this exact problem.

              • MUlissi
                MUlissi commented
                Editing a comment
                Haven't seen one prior to now, happy to absorb the information, but I'm almost never not going to ask 'why.' I don't expect someone will always have the answer, but that just means I'll ask someone else until I get the answer.

                Weird that it allows the spaces and dashes, but I'll be happy to start avoiding their use.

              • MUlissi
                MUlissi commented
                Editing a comment
                Got my answer. Conflicts arise in more advanced functions where the names are interpreted as math functions because of the characters, or misinterpretted because of spaces, periods, or whatever else. Makes sense from a computer programming standpoint. Seems to imply a limitation in the language PC DMIS is using, and a lack of fail-safe to disallow those characters in the naming scheme.

                Like old HTML that let you do some things it really shouldn't have let you do.

            • #9
              Reason for iterative: Keeping the part in car alignment, primarily. It's a practice I got used to in my last position, as it was a requirement by most of their customers.

              Unfortunately, they're not providing me with a literal print. I've got a sheet my boss put together that calls out A-1 without any specified locations for taking points, a second section on the same plane called A-2 that isn't tied to any particular feature besides the plane itself (which is why I say it's seemingly arbitrarily placed) and the hole, which is referred to as 'L1' on the print.

              One of the bent tabs has an illustrated rectangle shown up against it labeled 'Alignment Pin' which I've chosen to be the spot for the line I'm using to align it up against.

              I'm not trying to be over-vague with a lot of this, I'm just working with bare bones myself.

              It's not ideal, but it's generally workable when I have at least 2 holes to reference to with the alignment, and in this instance I do not.

              Comment

              Related Topics

              Collapse

              Working...
              X