location of a threaded hole

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  • location of a threaded hole

    hey guys, i'm having another issue, i have a part with a threaded hole and i need to get the location of the hole. i was told to use the auto circle feature and type in the pitch section the number of threads per inch for my part. well the thread is a 3/8-12 acme-2g (internal) and when i type in 12 for my pitch graphically the program goes crazy. but if i put in .012 its close but not on exactly. is there something different i should be doing for this? also i'd like to check the thread a few threads deep so i'd like to take approx 12 hits throughout the thread but it looks like i'm limited to 360 degrees. i'm not sure if there is somewhere that i can tell the auto feature that its a thread or how i can get it to check a few threads deep. thanks for your help
    V4.3 MR2

    weekend job
    http://i21.photobucket.com/albums/b2...DSC0994222.jpg

  • #2
    Originally posted by MustHaveBeenBlue View Post
    hey guys, i'm having another issue, i have a part with a threaded hole and i need to get the location of the hole. i was told to use the auto circle feature and type in the pitch section the number of threads per inch for my part. well the thread is a 3/8-12 acme-2g (internal) and when i type in 12 for my pitch graphically the program goes crazy. but if i put in .012 its close but not on exactly. is there something different i should be doing for this? also i'd like to check the thread a few threads deep so i'd like to take approx 12 hits throughout the thread but it looks like i'm limited to 360 degrees. i'm not sure if there is somewhere that i can tell the auto feature that its a thread or how i can get it to check a few threads deep. thanks for your help
    12 per inch is 0.08333333" pitch
    sigpic
    Originally posted by AndersI
    I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

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    • #3
      i feel dumb
      V4.3 MR2

      weekend job
      http://i21.photobucket.com/albums/b2...DSC0994222.jpg

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      • #4
        Originally posted by MustHaveBeenBlue View Post
        i feel dumb
        For once-around the hole, but down inside the hole, use the DEPTH setting.

        I think (and I have NOT tried this myself, but have ONLY heard about it) you can tell it to start at 0 and go to 720 and it will go around twice.
        sigpic
        Originally posted by AndersI
        I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

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        • #5
          I use the auto cylinder with pitch. Three layer 7 hit each layers
          Global Image 7107 4.2 MR1
          Global Advantage 575 4.2 MR1
          Mitutoyo FN1106 4.2 MR1 with STI

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          • #6
            Originally posted by Matthew D. Hoedeman View Post
            For once-around the hole, but down inside the hole, use the DEPTH setting.

            I think (and I have NOT tried this myself, but have ONLY heard about it) you can tell it to start at 0 and go to 720 and it will go around twice.
            +1 Wes I believe turned me on to this. 0-720º with twice the normal number of hits. Goes around twice.

            Back to the pitch thing.

            As Matt said, you want to enter the pitch. That is, the inverse of the number of threads per unit of measure.

            It so happens that with English or 'Standard' threads (those measured in inches) are normally called out as threads per inch. So, for example the pitch of a 1/4-20 thread is 1/20 = .05.

            Now metric threads on the other hand are called out using the pitch, not the number of threads per mm. For example, an M10 X 1.5 thread has a pitch of 1.5. No math necessary.

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            • #7
              Oh, and I'll go ahead and add that if you want to use the pitch function with an auto cylinder, for best results you'll want to space the rows of hits such that the distance between them is a multiple of the pitch. That way it will hit on the same part of the thread profile on all rows.

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              • #8
                Originally posted by Goodluck View Post
                Oh, and I'll go ahead and add that if you want to use the pitch function with an auto cylinder, for best results you'll want to space the rows of hits such that the distance between them is a multiple of the pitch. That way it will hit on the same part of the thread profile on all rows.
                I hope no one minds a minor thread hijack, but I have a question pertaining to cylinders. If I have a bore that is 50mm deep, and I want to take three rows, one at the bottom, one in the middle and one at the top, what should I put in the auto feature values. I can never get this to work out corectly for some reason. I either go way to deep or the rows don't go where I want them.

                The other problem I have is measuring a male protrusion as a cylinder. The machine always goes the wrong direction. Same example, I click stud, tell it a height of 50mm, with a neg spacer value. It tkaes the surface hits correctly, then tries to back up and take the hits out in the air, not on the protrusion.

                Lastly, about half the time, the machine tells me my centerline vector is parallel to the feature vector or some such nonsense when trying to do cylinders manually. Why would it do that?

                I hate cylinders

                Thank you.
                If clutter is a sign of genius, I must be qualified to teach guys like Einstein and other smarty pantses

                B & S 7-10-7
                pcdmis cad++ 3.25mr3

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                • #9
                  Originally posted by jay R View Post
                  I hope no one minds a minor thread hijack, but I have a question pertaining to cylinders. If I have a bore that is 50mm deep, and I want to take three rows, one at the bottom, one in the middle and one at the top, what should I put in the auto feature values. I can never get this to work out corectly for some reason. I either go way to deep or the rows don't go where I want them.

                  The other problem I have is measuring a male protrusion as a cylinder. The machine always goes the wrong direction. Same example, I click stud, tell it a height of 50mm, with a neg spacer value. It tkaes the surface hits correctly, then tries to back up and take the hits out in the air, not on the protrusion.

                  Lastly, about half the time, the machine tells me my centerline vector is parallel to the feature vector or some such nonsense when trying to do cylinders manually. Why would it do that?

                  I hate cylinders

                  Thank you.
                  About the ONLY thing I can tell you for the AUTO FEATURE cylinder is to turn ON the "paths" in the window and watch what each change does to the touches. If, as in V3.7, it won't show them to you when creating it, create it (don't measure it), then close the window, then F9 the feature, it will then show the path of the touches. You can then play with all the values to get what you need.
                  sigpic
                  Originally posted by AndersI
                  I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

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                  • #10
                    heh heh......... He said "Male Protrusion"
                    sigpic What's our Vector, Victor?

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                    • #11
                      I use a thread gage, use a screw driver to pop it out of the holder, screw it into the hole and measure the stud as close to the base as possible. Since a threaded hole is rarely perpendicular.

                      A.Gore
                      sigpicA.Gore

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                      • #12
                        Originally posted by Matthew D. Hoedeman View Post
                        About the ONLY thing I can tell you for the AUTO FEATURE cylinder is to turn ON the "paths" in the window and watch what each change does to the touches. If, as in V3.7, it won't show them to you when creating it, create it (don't measure it), then close the window, then F9 the feature, it will then show the path of the touches. You can then play with all the values to get what you need.
                        +1 again, it is helpful to see what each change does.

                        In 3.7mr3 (might be different for your version) for an internal cylinder with a vector of 0,0,1...

                        set your z value to the surface the cylinder penetrates
                        set the depth value (positive value) to how far down from the surface you want it to measure the row of hits closest to the surface.
                        set the height value (positive value) to how far down from the surface you want it to measure the row of hits farthest from the surface.

                        So say you have a hole which pierces a surface and is 1 inch deep and you are using a 4mm probe. You want to miss the .05 lead in chamfer and measure as deep as possible.

                        z value = 0
                        depth value = .1 (you'll measure .05 deeper than the end of the chamfer)
                        height value = .91 (1 - .08 (probe radius) - .01 (clearance)) You'll measure with the probe having .01 clearance from the bottom of the hole.

                        Now, say you want to do it the other way round where you want to start at the bottom of the hole.

                        Z=-1
                        depth = distance up from the bottom (positive value) = .09 (probe radius plus .01 clearance)
                        height = distance up from the bottom (negative value) = -.99 (.01 down from the top, .05 down from the chamfer end.

                        In both cases, the middle rows will be evenly spaced between the top and bottom row.
                        Last edited by #2#; 05-06-2009, 11:23 AM.

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                        • #13
                          In addition the Start/End angle is important. Make sure hits go along with the spiral (i.e. 0 to -360 deg.)

                          Gracias!!
                          sigpicIt's corona time!
                          737 Xcel Cad++ v2009MR1....SE HABLA ESPAÑOL

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                          • #14
                            Thank you, I will give these tips a try.

                            I did not know you could use the height when doing a cylinder hole type thing a ma jig, I thought it was for protrusions only

                            Stupid cylinders
                            Last edited by jay R; 05-06-2009, 11:40 AM.
                            If clutter is a sign of genius, I must be qualified to teach guys like Einstein and other smarty pantses

                            B & S 7-10-7
                            pcdmis cad++ 3.25mr3

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                            • #15
                              Originally posted by jay R View Post
                              Thank you, I will give these tips a try.

                              I did not know you could use the height when doing a cylinder hole type thing a ma jig, I thought it was for protrusions only

                              Stupid cylinders
                              A stud (external cylinder) is done in much the same way only (obviously) the check box for stud is selected instead of hole.

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