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GEOTOL help

management had me run a test. I taped a 2,4,6 block to the table. took the top plane, x+ and y- and created my alignment. I then called them datum a top b x and c y. I measured 2 holes on each side and did a position in geotol. I used the same measured data in legacy and got a .010 difference. How can this be?

What management is saying is the position formula. 2 x (dx^2 + dy^2)^1/2 when you figure it manually using the measured values matches legacy perfectly but it is not matching in GEOTOL.

I understand this is rough and dirty test but I can not explain why parts we measure good with second methods and legacy are good. GEOTOL (which our customer uses and requires) is failing the part. I have asked Hexagon this question and keep being told that GEOTOL is correct to the standard. Which is great but the standard use the 2 x (dx^2 + dy^2)^1/2 formula and is passing this but failing in GEOTOL.

I am not bashing PCD Hexagon or anything but I can not explain it to management.

What am I missing??​
Parents Reply Children
  • Create new alignments that match the GeoTol alignments before you dimension the True Positions in Legacy. Also, make sure your workplanes are correct. You are comparing apples to oranges right now.
  • But what does the alignment have to do with it. The DRF is correct in both. Is it calculating the alignment and the DRF? The FCF calls for ABC and the DRF is ABC not sure why the alignment matters once it has established the part location.

    If the DRF and the alignment are both used in the calculation that explains why my stuff is off but I do not understand the reason why it would use both. If you set you datum a plane as datum a it should not matter where your alignment is as datum a is datum a.
  • Mike

    this code was also not comparing legacy to GEOTOL. This is all in geotol. Sorry I should have separated the 2 parts.
  • Like Ruff said, your alignments are not the same. So you can't compare the 2. For instance, you are leveling on the b datum plane in your legacy and leveling on the A datum plane in Geotol. And "no", the alignments of legacy and geotol are not used in conjunction with each other. It either uses one or the other depending on how you report it out. Try matching your datums schemes to each other in the same order.
  • mike and mark I am not understand what your talking about. I have 1 man alignment and 1 dcc alignment. I am not using legacy at all. This is all geotol. my datums are top plane b front plane a and side c

    MAN_ALIG =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
    ALIGNMENT/LEVEL,ZPLUS,MAN_DATUM_B
    ALIGNMENT/TRANS,ZAXIS,MAN_DATUM_B
    ALIGNMENT/ROTATE,YMINUS,TO,MAN_DATUM_A,ABOUT,ZPLUS
    ALIGNMENT/TRANS,YAXIS,MAN_DATUM_A
    ALIGNMENT/TRANS,XAXIS,MAN_C
    ALIGNMENT/END
    MODE/DCC
    DCC_DATUM_B=FEAT/CONTACT/PLANE/DEFAULT,CARTESIAN,TRIANGLE,LEAST_SQR
    THEO/<1.6683,0.8577,0>,<0,0,1>
    ACTL/<1.6683,0.8577,0>,<0,0,1>
    TARG/<1.6683,0.8577,0>,<0,0,1>
    ANGLE VEC=<1,0,0>,SQUARE
    SHOW FEATURE PARAMETERS=NO
    SHOW CONTACT PARAMETERS=YES
    NUMHITS=2,NUMROWS=2
    SPACER=0.6
    AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
    SHOW HITS=NO
    DCC_DATUM_A=FEAT/CONTACT/PLANE/DEFAULT,CARTESIAN,TRIANGLE,LEAST_SQR
    THEO/<1.7627,0,-0.8071>,<0,-1,0>
    ACTL/<1.7627,0,-0.8071>,<0,-1,0>
    TARG/<1.7627,0,-0.8071>,<0,-1,0>
    ANGLE VEC=<1,0,0>,SQUARE
    SHOW FEATURE PARAMETERS=NO
    SHOW CONTACT PARAMETERS=YES
    NUMHITS=2,NUMROWS=2
    SPACER=0
    AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
    SHOW HITS=NO
    DCC_DATUM_C=FEAT/CONTACT/PLANE/DEFAULT,CARTESIAN,TRIANGLE,LEAST_SQR
    THEO/<0,2.7109,-0.5737>,<-1,0,0>
    ACTL/<0,2.7109,-0.5737>,<-1,0,0>
    TARG/<0,2.7109,-0.5737>,<-1,0,0>
    ANGLE VEC=<0,0,1>,SQUARE
    SHOW FEATURE PARAMETERS=NO
    SHOW CONTACT PARAMETERS=YES
    NUMHITS=2,NUMROWS=2
    SPACER=0
    AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=0.3937,DISTANCE AFTER=0.3937,DIRECTION=ALONG FEATURE VECTOR
    SHOW HITS=NO
    DCC_DATUM_C=ALIGNMENT/START,RECALL:STARTUP,LIST=YES
    ALIGNMENT/LEVEL,ZPLUS,DCC_DATUM_B
    ALIGNMENT/TRANS,ZAXIS,DCC_DATUM_B
    ALIGNMENT/ROTATE,YMINUS,TO,DCC_DATUM_A,ABOUT,ZPLUS
    ALIGNMENT/TRANS,YAXIS,DCC_DATUM_A
    ALIGNMENT/TRANS,XAXIS,DCC_DATUM_C
    ALIGNMENT/END