TP angle only

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

  • TP angle only

    I have a part with 5 holes drilled into the circumference of the part. All are in line in Z, but are 10 degrees apart from each other in polar angle. The print shows TP .012 (no datum). The only basic is the 10 degree. The z location is toleranced. (Yes, I know that is wrong but the part is older than I am, not gonna get it fixed). We are only applying the angle for TP. I measured 2 parts. One had a result of .120 from nominal on the 10 degree, and TP was reported as good. The next had .100 from the 10 degree, but TP was bad. Does PCDMIS automatically use X,Y,Z for TP? Am I approaching this the wrong way from the PCDMIS stand point? Still using v3.2063.
    When in doubt, post code. A second set of eyes might see something you missed.
    sigpic

  • #2
    In the past with parts like this I used the 10 degrees as the basic and toleranced the x,z only.
    "A good design is the one that allows engineers the ability to change gracefully what they forgot to do right the first time!!!"

    Comment


    • #3
      I have not been successful in using an angle for TP.

      My input would be, as you will probably find if you dimension XYZ, that TP is taken from them.
      http://baggy3.info/signani3.gif
      Excercise your mind,..... muscle works better than fat!!

      Comment


      • #4
        You are using 3.2063, there were some funny bugs when TPing outside of the X,Y plane with that version. You could try doing your alignment so all the holes are in the X,Y plane and TP them after that alignment. Might not fix it as I've never TP'd just angle but I do know that there were issues around your version when doing TP on any features outside the X,Y axis locations.
        <internet bumper sticker goes here>

        Comment


        • #5
          I have run across a few TP's with angles. I have never gotten one to work.

          OK, so you have a basic dim. of 10º and your fcf says .120 correct?

          Is .120 in inches or degrees?

          Of course, I believe TP must ALWAYS have a datum reference to be valid.

          I'd just tell them the drawing is garbage as is and that you need a clearer drawing if they want the part checked.

          This would be so much easier if it was called out as angularity!

          Comment


          • #6
            I think we have explored the TP with no datum reference b4. One with no datum defaults to the main datum setup. No TP to them, but TP to nominals.
            http://baggy3.info/signani3.gif
            Excercise your mind,..... muscle works better than fat!!

            Comment


            • #7
              The drawing is crap but you probably have to live with it. Is this a hole pattern with groups of holes at 10 degrees?
              "A good design is the one that allows engineers the ability to change gracefully what they forgot to do right the first time!!!"

              Comment


              • #8
                Can you rotate for each hole and tolerance to zero/zero?
                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.

                Comment


                • #9
                  If I'm picturing this correctly, your part circumference should be a datum, and one of the 5 holes should be a datum. I would align to these, where your circumference datum would be the origin and the hole datum would be Y-zero. Then each of the other 4 holes would sweep 10 degrees from this alignment, right? If so, I would measure the first hole, (datum), then rotate my alignment +/- 10° and measure the next, using zero as my nominal angle and tolerance from that. Of course, I'm not using PC-dmis yet so this technique could be useless here.
                  sigpic
                  Global Advantage 12-22-10
                  TESASTAR M SP25 4.3mr2

                  Comment


                  • #10
                    Thanks for all the ideas. I was measuring the holes as cylinders. I have changed to circles and so far my CMM reports are correlating with other methods. Could be that the holes are tapped (yes I use pitch). But problem solved. I know I can explain this to the customer source guy. He is very understanding of these situations.
                    When in doubt, post code. A second set of eyes might see something you missed.
                    sigpic

                    Comment


                    • #11
                      Never had a problem using x,y y,z or z,x WP position w/ 32063/ I still use it.
                      0.02
                      Kev
                      RFS Means Really Fussy Stuff

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

                      Comment


                      • #12
                        Originally posted by kbotta
                        Never had a problem using x,y y,z or z,x WP position w/ 32063/ I still use it.
                        0.02
                        Kev
                        It might be an MR thing. Used to be with that version if you TP'd any axis other than X,Y (ie X,Z true position) it did not calculate the TP properly. Probably fixed with MR.

                        Craig
                        <internet bumper sticker goes here>

                        Comment


                        • #13
                          Thanks again to everyone. I found a flaw in the alignment. Stupid programmer . There I go talking out loud again. I fixed my alignment and parts look good!
                          When in doubt, post code. A second set of eyes might see something you missed.
                          sigpic

                          Comment

                          Related Topics

                          Collapse

                          Working...
                          X