Material condition on datums

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

  • terry
    replied
    yes but .130 is more than .112. I agree that when using datums the MMC (.130) error is less than the RFS (.177) error. What I dont understand why when using datums off the error is less that using datums on.
    Regards,
    Terry

    Leave a comment:


  • J Temmen
    replied
    I believe 0.130 is less then 0.177.

    Leave a comment:


  • terry
    started a topic Material condition on datums

    Material condition on datums

    Can any one explain to me how using datums on could increase my positional error? Below is the same feature true positioned three ways, first is with datums off (.112), next datums on using MMC (.130) and finally datums on at RFS (.177). If PC-Dmis is best fitting the datums to simulate a hard gage check how can my true position error be greater by using datums @ MMC? Current alignment is -E- -C- -M-, bonus does not apply to hole because it is a threaded hole.

    DIM LOC119= TRUE POSITION OF CIRCLE E_CIRCLE3 UNITS=MM ,$
    GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH DEV PERPEN CENTERLINE=OFF DISPLAY=DIAMETER
    AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL
    X 400.800 400.826 0.026
    Y -86.500 -86.450 0.049
    DF 10.500 0.100 0.100 10.592 0.092 0.000 --------#
    TP RFS 0.800 0.000 0.112 0.000 -#-------
    END OF DIMENSION LOC119
    DIM LOC120= TRUE POSITION OF CIRCLE E_CIRCLE3 UNITS=MM ,$
    GRAPH=OFF TEXT=OFF MULT=50.00 OUTPUT=BOTH DEV PERPEN CENTERLINE=ON DISPLAY=DIAMETER
    AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL
    X 400.800 400.738 -0.063
    Y -86.500 -86.517 -0.017
    DF 10.500 0.100 0.100 10.592 0.092 0.000 --------#
    D1 PLANE DATUM_E_DCC AT RFS
    D2 12.763 0.020 0.020 0.014 12.757 CIRCLE DATUM_C_DCC AT MMC
    D3 82.626 0.020 0.020 0.026 82.632 CIRCLE DATUM_M_BORE AT MMC
    TP RFS 0.800 0.000 0.130 0.000 -#-------
    END OF DIMENSION LOC120
    DIM LOC121= TRUE POSITION OF CIRCLE E_CIRCLE3 UNITS=MM ,$
    GRAPH=OFF TEXT=OFF MULT=50.00 OUTPUT=BOTH DEV PERPEN CENTERLINE=OFF DISPLAY=DIAMETER
    AX NOMINAL +TOL -TOL BONUS MEAS DEV OUTTOL
    X 400.800 400.717 -0.083
    Y -86.500 -86.530 -0.031
    DF 10.500 0.100 0.100 10.592 0.092 0.000 --------#
    D1 PLANE DATUM_E_DCC AT RFS
    D2 12.763 0.020 0.020 12.757 CIRCLE DATUM_C_DCC AT RFS
    D3 82.626 0.020 0.020 82.632 CIRCLE DATUM_M_BORE AT RFS
    TP RFS 0.800 0.000 0.177 0.000 -#-------
    END OF DIMENSION LOC121

    Regards
    Terry

Related Topics

Collapse

Working...
X