Non Circular True Position

  • Filter
  • Time
  • Show
Clear All
new posts

  • Non Circular True Position

    i know this has been discussed in the past, but I catch on slowly and would like to revisit the subject.
    True position of a non circular feature such as a the 2 edges of a D Hole with an MMC modfier. ( Position of the center line )
    It has been suggested to create a generic circle and place a variable equal to the distance measured between the 2 edges into the measured diameter of the generic circle. So far so good.
    What about the XYZ nominals and measured values of the circle?
    Do I get the theoreticals from the created center line of the d hole?
    Do I create variables relating to the centerline and place them into measured values of the circle?
    I am attempting to use the new GD&T dimensioning found in V4.1
    ["Paper is poverty,... it is only the ghost of money, and not money itself." --Thomas Jefferson ][/SIGPIC]

  • #2
    It depends on what has a modifier applied to it. If it is the DF then assign a variable that derives a bonus and simply type the variable into the tolerance field in your dim ; i.e. .005+MMC. However, if there are multiple modifiers then it gets a whole lot more complex.
    sigpic 1.61803399Δ


    • #3
      Create the x, y, or z location using a midpoint between the two points on the outside edges of your part, save the measured value of that midpoint as a variable and insert that into your generic circle as the measured value.
      sigpic Eye Yam Sofa King We Todd It.


      • #4
        Do I Place the variable into all 3 axis or do I place the variable only into the axis of concern?
        ["Paper is poverty,... it is only the ghost of money, and not money itself." --Thomas Jefferson ][/SIGPIC]


        • #5
          If you are reporting "X", for example, then place your variable in the "X" location in the generic feature. Place nominal values for the others or else the location of the gen feature in the graphics screen will look off.
          sigpic GDTPS - 0584


          Related Topics