hexagon logo
Register Sign in
  • Replies 7 replies
  • Subscribers 32 subscribers
  • Views 98 views
  • Users 0 members are here
Options
Related

Vector Deviations gone awry

mjdevries
I received data from a PC-DMIS cmm and was reviewing it. We receive the data with the XYZ and the Vector deviation information. I was reviewing this data and I noticed that the vector deviation was much larger than the sqrt of the sum of the squares of the coordinate deviations, AKA, the absolute deviation. I reviewed the PC-DMIS program and found that the nominal in the CALL/EXTERN statement did not match the feature declaration statement which defines the nominals that are used in the X, Y, and Z outputs. I'm assuming the CALL/EXTERN statement defines the vector measurement from the nominal point in the call statement. Does this make sense?

F(M1)=FEAT/POINT,CART,590.878, -687.587,662.998,0.0459841,-0.998654,0.0239917
CALL/EXTERN,DMIS,M(PCD_AUTO_VECTOR_POINT_605),(M1),590.878, -690.59,$
662.998,0.0459841,-0.998654,0.0239917,VEC,0.0459841,-0.998654,0.0239917,$
0.0459841,-0.998654,0.0239917,'THEO_THICKNESS',0,'NO','NO',0
Parents
  • Theo <> thickness

    In your example DMIS code, the coordinate value in the CALL/EXTERN statement is the Target for the feature. In PC-DMIS, it can be acceptable to have a difference between the Nominal and Target values. Here is what the command would look like in the PC-DMIS Edit Window in Command Mode:

    M1 =FEAT/CONTACT/VECTOR POINT,CARTESIAN
    THEO/<590.878,-687.587,662.998>,<0.0459841,-0.998654,0.0239917>
    ACTL/<590.878,-687.587,662.998>,<0.0459841,-0.998654,0.0239917>
    TARG/<590.878,-690.59,662.998>,<0.0459841,-0.998654,0.0239917>
    SNAP=NO
    SHOW FEATURE PARAMETERS=NO
    SHOW CONTACT PARAMETERS=NO

    and for the v3.7 fans:

    M1 =AUTO/VECTOR POINT,SHOWALLPARAMS = YES
    THEO/590.878,-687.587,662.998,0.0459841,-0.998654,0.0239917
    ACTL/590.878,-687.587,662.998,0.0459841,-0.998654,0.0239917
    TARG/590.878,-690.59,662.998,0.0459841,-0.998654,0.0239917
    THEO_THICKNESS = 0,RECT,SNAP = NO,$
    AUTO MOVE = NO,DISTANCE = 0

    From your post, I am unable to determine why the Target is different from the Nominal values. I can see that SNAP is disabled, and no thickness offset is applied to the measurement.
Reply
  • Theo &lt;&gt; thickness

    In your example DMIS code, the coordinate value in the CALL/EXTERN statement is the Target for the feature. In PC-DMIS, it can be acceptable to have a difference between the Nominal and Target values. Here is what the command would look like in the PC-DMIS Edit Window in Command Mode:

    M1 =FEAT/CONTACT/VECTOR POINT,CARTESIAN
    THEO/<590.878,-687.587,662.998>,<0.0459841,-0.998654,0.0239917>
    ACTL/<590.878,-687.587,662.998>,<0.0459841,-0.998654,0.0239917>
    TARG/<590.878,-690.59,662.998>,<0.0459841,-0.998654,0.0239917>
    SNAP=NO
    SHOW FEATURE PARAMETERS=NO
    SHOW CONTACT PARAMETERS=NO

    and for the v3.7 fans:

    M1 =AUTO/VECTOR POINT,SHOWALLPARAMS = YES
    THEO/590.878,-687.587,662.998,0.0459841,-0.998654,0.0239917
    ACTL/590.878,-687.587,662.998,0.0459841,-0.998654,0.0239917
    TARG/590.878,-690.59,662.998,0.0459841,-0.998654,0.0239917
    THEO_THICKNESS = 0,RECT,SNAP = NO,$
    AUTO MOVE = NO,DISTANCE = 0

    From your post, I am unable to determine why the Target is different from the Nominal values. I can see that SNAP is disabled, and no thickness offset is applied to the measurement.
Children
No Data
© 2024 Hexagon AB and/or its subsidiaries. Privacy Policy | Cloud Services Agreement