True position with projected toleralce

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  • True position with projected toleralce

    I am starting to see this more offten and I am not sure on how to program and diminetion this call out position of .010m/P .250/A/B/C. any help would be nice thanks
    Big Al ;) :p
    Global 5-7-5
    Windows XP
    Ver 4.2

  • #2
    The tolerance zone is projected a distance of 0.250 from the face of the feature (which hopefully is specified as the primary datum). Hopefuly Kev will correct me and/or elaborate if necessary. I am so-so with 14.5 but no expert (plus someone stole my copy, I need to order another one)
    <internet bumper sticker goes here>


    • #3
      I know what it means but how to you do it in pcdmis
      Big Al ;) :p
      Global 5-7-5
      Windows XP
      Ver 4.2


      • #4
        That is actually an old callout. What it is asking you to do is to constuct a point in space and do a basic true position. I bet the call out is to a cylinder. The mating part will be a that projected distance. And they want to make sure, that the shaft ( or whatever) will be going true thru the part to the mating part. The old school layout we would use pins to check it. You could use a pin to check your projected answer. Am I right?
        sigpicSummer Time. Gotta Love it!


        • #5
          V4.0 makes evaluating dimensions like that real easy. You can enter them just the way they appear in the FCB. And indeed, the TP is projected out .25 above the primary datum. So if there is an out-of-sqaure situation, this will have an effect on your TP when projected out .25.

          PC-DMIS/NC 2010MR3; 15 December 2010; running on 18 machine tools.
          Romer Infinite; PC-DMIS 2010 MR3; 15 December 2010.


          • #6
            I agree with you Craiger (AKA Picker)

            A couple of ways to get that as with most things with PCDMIS
            You could create an offset plane out to that projected distance and pierce a point out there from a cylinder you would create in the feature. Pretty sure on the Pierce thing. I don't believe you would want to use projected point as it does not change the location if you have any variation in your cylinder.
            If I am wrong I appoligize it's late in the day..


            • #7
              thanks for all the help I just have not had the this call out before know and forgot on how to do it thanks for all the help.
              Big Al ;) :p
              Global 5-7-5
              Windows XP
              Ver 4.2


              • #8
                reference length box

                Is this not what the reference length bos is for??? You must select "start point of axis" and your cylinder start point must be at the face. Someone, anyone, please correct me if I am wrong. I just reread the help menu on this, and I am pretty sure this works this way. HTH
                sigpic"Hated by Many, Loved by Few" _ A.B. - Stone brewery


                • #9
                  Played with the offline (V3.5MR2) and keyed in what you are wanting to do and it as Wes states.

                  Go to "Dimension" > "True Position" box and use "From start point of axis". You will have to keyin a negative reference length to get TP projected above the surface which does not make sense. I thought that a negative entry would put it below the surface.

                  I keyed in a cylinder at 5° nominal to ehe XYZ origin just so I could visualize what I was doing, then keyed in a generic point to the coords displayed of the projected TP and verified the location of results to visually see that it was correct.

                  Last edited by dwade; 01-14-2008, 09:11 AM.
                  Xcel & MicroVal Pfx & Global 37mr4 thru 2012mr1sp3
                  Contura Calypso 5.4

                  Lord, keep Your arm around my shoulder and Your hand over my mouth. Amen.


                  • #10
                    Originally posted by Paul Sarrach
                    That is actually an old callout.
                    Actually, no...It is a 'new' callcout. (unless you were reffering to "we've been checking this for years...then yes - it is old- LOL)
                    If it were '82 [14.5], the [P] would have been attached to the lower portion of the FCF in a box. Being that it is included inside the FCF, shows this to be a '94 [14.5] drawing.

                    Good advice on this board as to the inspection method.

                    RFS Means Really Fussy Stuff

                    When all you have is a hammer - everything looks like a nail....


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