3 Basic Dimensions (3D true position)

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

  • 3 Basic Dimensions (3D true position)

    How do I report the True Position using 3 Basic Dimensions?

    I have 3 Basic Dimensions and I do not know how to report the True Position for this scenario. I've always only had 2 Basic Dimensions. Shall I anticipate problems with PC-DMIS reporting correctly or is the use of 3 Basic's a normal thing?

    Thanks again.
    Your life is happening, Participate!

  • #2
    Not sure how to do it in PCDMIS but it is 2x the √of x²+y²+z² . I used to have a lot of items like this on some Wing struts that I used to check.
    Tolerance challenged ... Living in the world of unseen lines.

    This software isn't buggy its an infestation

    Comment


    • #3
      Originally posted by Big Red View Post
      How do I report the True Position using 3 Basic Dimensions?

      I have 3 Basic Dimensions and I do not know how to report the True Position for this scenario. I've always only had 2 Basic Dimensions. Shall I anticipate problems with PC-DMIS reporting correctly or is the use of 3 Basic's a normal thing?

      Thanks again.
      Check your feature with sample hits. That way you can include X,Y and Z as part of your true position.
      sigpicIt's corona time!
      737 Xcel Cad++ v2009MR1....SE HABLA ESPAÑOL

      Comment


      • #4
        Originally posted by Roberto View Post
        Check your feature with sample hits. That way you can include X,Y and Z as part of your true position.
        A minimum of 3 sample hits.
        sigpic
        Originally posted by AndersI
        I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

        Comment


        • #5
          Sounds as though you have a spherical tolerance. Its the same as with 2 basic dimensions but the 3rd one takes you into the third dimension. If you have ever seen the film Explorers then this will help you visualize it.
          Recently jumped from 3.5 Mr 2 CAD
          to 2012 CAD++

          Comment


          • #6
            Originally posted by Farmer View Post
            Sounds as though you have a spherical tolerance. Its the same as with 2 basic dimensions but the 3rd one takes you into the third dimension. If you have ever seen the film Explorers then this will help you visualize it.
            Right on...
            RFS Means Really Fussy Stuff

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

            Comment


            • #7
              In days of old, before Wilcox/B&S screwed the software up, you COULD use the S axis when dimensioning a hole that had 3 or more sample hits and report the theo surface deviation at the center of the hole to help people keep straight what was what, and the TP perp to CL gave you the remaining answer to the puzzle. I am not sure if the S still works for a hole or not, I haven't tried it in a long time. Those 2 options gave you the surfaec deviation and the stab-pin answer for a hole, this was very helpful for sheet metal, probably not so much for milled parts that don't have surface variation (movement, off-nominal, whatever) that you see in sheet metal.

              Doing TP with all 3 axis CAN start getting confusing real quick. You might want to report the TP-perp-cl as well, as a seperate dimension so YOU and your people can see what you actually have for 2-axis hole deviation, the perp-cl will give you a strictly 2-D look at the hole, even if it is on a 3-D surface.
              sigpic
              Originally posted by AndersI
              I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

              Comment


              • #8
                Originally posted by kbotta View Post
                Right on...
                Uh huh...
                Recently jumped from 3.5 Mr 2 CAD
                to 2012 CAD++

                Comment


                • #9
                  But, but, but...

                  My 3 Basics are to an angled hole at the break out on it's spotface. I would measure the spotface, rotate alignment, measure the hole, project to the spotface, rotate the alignment back and then I would report. Stay with me here...

                  1 basic is in "X" from a plane.
                  1 basic is in "Y" from a plane.
                  1 basic is in "Z" from center of a bore.

                  If this is the case, do I still need 'Sample Points' as stated earlier?

                  Again, I bow to your expertice.
                  Your life is happening, Participate!

                  Comment


                  • #10
                    YEP, you need to have the hole located EXACTLY on the part surface, and correctly orientated, so 3 sample hits, minimum, required.
                    sigpic
                    Originally posted by AndersI
                    I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

                    Comment


                    • #11
                      Why not build an alignment based on all of your basics and report its deviation while in that "basic" alignment? would it not produce the same thing?

                      Comment


                      • #12
                        Originally posted by R2ah1ze1l View Post
                        Why not build an alignment based on all of your basics and report its deviation while in that "basic" alignment? would it not produce the same thing?
                        Thread is over 5 years old.

                        B&S CHAMELEON/PCDMIS CAD++ V2011

                        There are no bugs, only "UNDOCUMENTED ENHANCEMENTS!"

                        sigpic

                        Comment


                        • #13
                          Originally posted by dph51 View Post
                          Thread is over 5 years old.
                          Got a problem with necromancy?
                          Lately, it occurs to me
                          What a long, strange trip it's been.

                          2017 R1 (Offline programming)

                          Comment


                          • #14
                            Yea, stubled on this and shouldn't have bothered posting. Sorry, didn't check dates

                            Comment


                            • #15
                              3 basic dimensions for a true position ?
                              never of heard of such a thang ........................
                              I AM the one who KNOCKS !

                              Comment

                              Related Topics

                              Collapse

                              Working...
                              X