Perpendicularity Being Reported as Zero?

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

  • Perpendicularity Being Reported as Zero?

    Good morning. I am attempting to find out why my perpendicularity is being reported as zero every time I run a part. This particular perpendicularity has no diameter associated with it. See the screenshot attached.

    I tried both:

    Xact measure- simple plane generic feature set created from 2 sets of hits on both walls and referenced that against Datum A to find the perpendicularity.
    Legacy - created a constructed midplane from 2 planes (that were created from the set of hits on each wall) and referenced that against Datum a to find the perpendicularity.

    See the code below for both the generic feature set creation and the dimensions I created. Both methods came back with 0. Would anyone be able to provide some insight? It would be appreciated, thank you.

    Generic Feature Set Creation

    Code:
    FT1 =FEAT/SET,CARTESIAN
    THEO/<-8.099,1.5,5.507>,<0,0,1>
    ACTL/<-8.153,1.501,5.508>,<0,0,1>
    CONSTR/SET,BASIC,RR85,RR86,RR87,RR88,RR89,RR90,RR91,RR92, RR93,RR94,,
    FT2 =FEAT/SET,CARTESIAN
    THEO/<8.103,1.333,6.078>,<0,0,1>
    ACTL/<8.092,1.333,6.088>,<0,0,1>
    CONSTR/SET,BASIC,RR95,RR96,RR97,RR98,RR99,RR100,RR101,RR1 02,RR103,RR104,RR105,RR106,,
    FT3 =FEAT/SET,CARTESIAN
    THEO/<0.738,1.409,5.818>,<0,0,1>
    ACTL/<0.708,1.409,5.824>,<0,0,1>
    CONSTR/SET,BASIC,FT1,FT2,,
    Both XactMeasure and Legacy Reporting

    Code:
    F3 =GENERIC/PLANE,DEPENDENT,CARTESIAN,$
    NOM/XYZ,<FT3.TX,FT3.TY,FT3.TZ>,$
    MEAS/XYZ,<FT3.X,FT3.Y,FT3.Z>,$
    NOM/IJK,<1,0,0>,$
    MEAS/IJK,<1,0,0>
    PERP13_1 =PERPENDICULARITY : F3
    FEATCTRLFRAME/SHOWPARAMS=NO,SHOWEXPANDED=NO
    DIMENSION/PERPENDICULARITY,0.1,A,,
    NOTE/PERP13_1
    FEATURES/F3,,
    DIM PERP13= PERPENDICULARITY OF PLANE PLN8,RFS TO PLANE DATUM_A,RFS UNITS=MM ,$
    GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
    AX NOMINAL MEAS +TOL -TOL DEV OUTTOL
    M 0.000 0.000 0.100 0.000 0.000 0.000 #--------
    Attached Files

  • #2
    Have you tried measuring each side of the width as a planar feature and constructing a width feature from the two?

    Comment


    • #3
      What Jacob said. I thought of that when I noticed 1 set has more "points" than the other. 2 options I would consider. do an opposing point on both walls then create a mid point. Do this as many times as you feel needed. Then take all the MIDPOINTS and create a PLN. Or create a pln on 1 side, then duplicate the hit locations on a pln on the other side, then create mid plan between the 2.

      Comment


      • BKulpa
        BKulpa commented
        Editing a comment
        I think Schlag's method is better, constructing features rather than sets which are just collections of points.

    • #4
      1) In your generic feature, you made the actual vector 1,0,0, which is exactly perpendicular to the alignment it's created in.
      $ NOM/IJK,<1,0,0>,$ MEAS/IJK,<1,0,0>
      2) Generic feature doesn't have a size associated with it, so even if you get the correct vector, it has no size and all you have is an angle.

      3) I don't use that fancy new fangled GD&T, I stay with legacy, so I don't know that this is true for that, but constructed planes, like a midplane, have no form deviation, a factor in perpendicularity.

      Id strongly recommend measuring symmetrical points on each plane, taking the midpoint of each pair, then constructing the plane from the points - this will give you a valid perpendicularity,

      Comment


      • #5
        I agree with RandomJerk I noticed that when dimensioning perpendicularity of a midplane, the result would be zero everytime. Reason being, it's a construction (midplane) created off 2 more constructions (opposing planes.) This resulted in a midplane with no point data associated to it. Ever since then, I ALWAYS take equal and opposing points, create midpoints from opposing points, and construct a plane from those midpoints. Now the midplane has point data associated to it.
        In your code, you construct 2 separate sets, then construct a set off those sets which i think would do the same thing as I described. If you cannot create equal and opposing points due to the features not allowing it, then i would create a width feature like JacobCheverie said earlier.

        Comment


        • DAN_M
          DAN_M commented
          Editing a comment
          +1 VERY well said.

        • ALousyUser
          ALousyUser commented
          Editing a comment
          What an incredible comment. It makes a lot of sense! Silly me. I will give this a shot. Thank you.

      • #6
        This^^
        PC-DMIS CAD++ 2o19 R1 SP11

        Comment

        Related Topics

        Collapse

        Working...
        X