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  • Originally posted by tomato coupe View Post
    A typo in the chart does not invalidate the diagrams, which are self-consistent.
    The diagrams DO show the apparently same insert being used both ways. Note the way they show LH and RH in 1 thru 4, which appear to be correct. Compare 1 & 6, 2 & 5, where they appear to show the same type insert cutting in opposite helices.

    You have to make some assumptions to decide what they "must have meant"...... Which it is possible to do, they "must have meant" to show a LH where it appears identical to the RH..... but that rather invalidates the diagram as any sort of "authority" to be quoted, footnoted, etc.
    CNC machines only go through the motions.

    Ideas expressed may be mine, or from anyone else in the universe.
    Not responsible for clerical errors. Or those made by lay people either.
    Number formats and units may be chosen at random depending on what day it is.
    I reserve the right to use a number system with any integer base without prior notice.
    Generalizations are understood to be "often" true, but not true in every case.

    Comment


    • Originally posted by J Tiers View Post
      The diagrams DO show the apparently same insert being used both ways. Note the way they show LH and RH in 1 thru 4, which appear to be correct. Compare 1 & 6, 2 & 5, where they appear to show the same type insert cutting in opposite helices.

      You have to make some assumptions to decide what they "must have meant"...... Which it is possible to do, they "must have meant" to show a LH where it appears identical to the RH..... but that rather invalidates the diagram as any sort of "authority" to be quoted, footnoted, etc.
      I have no idea what point you're trying to make. The Korloy diagrams are fine, but you can completely dismiss them and introduce new ones if you prefer.

      Comment


      • Originally posted by tomato coupe View Post
        I have no idea what point you're trying to make. The Korloy diagrams are fine, but you can completely dismiss them and introduce new ones if you prefer.
        OK, Dan....

        Point nbeing that you cannot use the table on 5-8 as it is obviously wrong in one place. It also shows and lists both RH external tool and LH external tool as being used for opposite hand threads with same insert. Precisely what is being complained about.

        Nice enough drawings, but you have to supply your own content as to what goes with which.

        CNC machines only go through the motions.

        Ideas expressed may be mine, or from anyone else in the universe.
        Not responsible for clerical errors. Or those made by lay people either.
        Number formats and units may be chosen at random depending on what day it is.
        I reserve the right to use a number system with any integer base without prior notice.
        Generalizations are understood to be "often" true, but not true in every case.

        Comment


        • Originally posted by J Tiers View Post
          Point being that you cannot use the table on 5-8 as it is obviously wrong in one place.
          The only thing wrong is the CW/CCW entries have been flipped in the lower half of the chart.

          It also shows and lists both RH external tool and LH external tool as being used for opposite hand threads with same insert.
          RH inserts are not exclusively used for cutting a RH thread.

          Precisely what is being complained about.
          Who complained about what?

          Nice enough drawings, but you have to supply your own content as to what goes with which.
          Other than the noted typo, the diagrams are fine.

          Comment


          • The "EXT RH" and "EXT LH" in column 2 refer to the toolholder and the helix angle of the insert. I ground my threading tools to fit the helix angle. It was not as critical for 3/8"-16 standard threads, but makes a big difference for square threads.



            http://pauleschoen.com/pix/PM08_P76_P54.png
            Paul , P S Technology, Inc. and MrTibbs
            USA Maryland 21030

            Comment


            • Originally posted by tomato coupe View Post
              .....
              RH inserts are not exclusively used for cutting a RH thread.

              .
              The helix angle has been extensively commented on in posts above as part of the problem the OP is having, that the cutting is on the wrong side and so forth.

              Here we have what appears to be you discounting all that, and suggesting that there is NO helix angle problem whatsoever in the illustrations, despite the angle for LH and the angle for RH being opposite, as a basic part of the thread.

              Looking at the threads, one tilts to the left and the other to the right. An insert that is labeled for left hand, and one labeled for right hand, would be expected to have opposite tilts. If they do, then obviously one is not optimized for the opposite handed thread, when being held in the exact same position. Which is what would happen if the same holder and insert are used for the two different threads.

              Only if the insert is made universal for either handed thread , would there be no issue.

              However, the folks actually SHOW that there are 4 kinds of inserts.... in external, the coding for inserts shows that there are left and right handed inserts. That would certainly imply that there is a difference between the L and R handed inserts.

              And, if there is, then why is the RH insert AND holder being suggested for both hands of threads?
              Last edited by J Tiers; 03-29-2018, 11:45 PM.
              CNC machines only go through the motions.

              Ideas expressed may be mine, or from anyone else in the universe.
              Not responsible for clerical errors. Or those made by lay people either.
              Number formats and units may be chosen at random depending on what day it is.
              I reserve the right to use a number system with any integer base without prior notice.
              Generalizations are understood to be "often" true, but not true in every case.

              Comment


              • Originally posted by J Tiers View Post
                The helix angle has been extensively commented on in posts above as part of the problem the OP is having, that the cutting is on the wrong side and so forth.

                Here we have what appears to be you discounting all that, and suggesting that there is NO helix angle problem whatsoever in the illustrations, despite the angle for LH and the angle for RH being opposite, as a basic part of the thread.

                Looking at the threads, one tilts to the left and the other to the right. An insert that is labeled for left hand, and one labeled for right hand, would be expected to have opposite tilts. If they do, then obviously one is not optimized for the opposite handed thread, when being held in the exact same position. Which is what would happen if the same holder and insert are used for the two different threads.

                Only if the insert is made universal for either handed thread , would there be no issue.

                However, the folks actually SHOW that there are 4 kinds of inserts.... in external, the coding for inserts shows that there are left and right handed inserts. That would certainly imply that there is a difference, and that there is a difference between the L and R handed inserts.
                You can use a RH insert to cut either LH threads or RH threads, but you use different shims for the two applications. The shims change the angle.

                Comment


                • Originally posted by tomato coupe View Post
                  You can use a RH insert to cut either LH threads or RH threads, but you use different shims for the two applications. The shims change the angle.
                  The shim is not mentioned in the table or diagram, it is mentioned elsewhere. and another part of the info seems to associate one shim exclusively with ER, and the other with EL HOLDERS. Somewhat confusing

                  The various combinations and some of the given information manage to give the maximum appearance of conflict.... It starts to make sense once you decode a lot of the info and discount some of what appears to be said. The info in the table and diagram needs to be supplemented by info that is not referred to

                  An interesting system.

                  Apparently not what the OP has, so that special shim system does not apply in his case.
                  Last edited by J Tiers; 03-30-2018, 12:24 AM.
                  CNC machines only go through the motions.

                  Ideas expressed may be mine, or from anyone else in the universe.
                  Not responsible for clerical errors. Or those made by lay people either.
                  Number formats and units may be chosen at random depending on what day it is.
                  I reserve the right to use a number system with any integer base without prior notice.
                  Generalizations are understood to be "often" true, but not true in every case.

                  Comment


                  • Originally posted by J Tiers View Post
                    The shim is not mentioned in the table or diagram, it is mentioned elsewhere. and another part of the info seems to associate one shim with ER, and the other with EL HOLDERS.
                    Information for selecting shims appears on the same page as the previously referenced chart and diagram. Regardless, it is standard procedure to select the proper shim when you use this type of threading insert.

                    The various combinations and some of the given information manage to give the maximum appearance of conflict.... It starts to make sense once you decode a lot of the info and discount some of what appears to be said.
                    That one typo sure has thrown you off the scent.

                    An interesting system.

                    Apparently not what the OP has, so that special shim system does not apply in his case.
                    There is nothing special or unusual about this type of shim system -- it is quite common. That being said, it is possible that the OPs holder does not have a shim, because small internal boring-bar-type holders are often made with an effective shim angle that corresponds to the limited pitch / diameter combinations that are likely to be cut using a holder / insert of that physical size.

                    The OP's setup suffers from another issue, however, in that he is using an internal thread insert to cut external threads at a relatively small diameter, so the radial clearance angle will not be correct.

                    Have you ever used this type of threading insert?

                    Comment


                    • Those are laydown. I think I have some that came to me in a toolbox. Have not used them, IIRC they are "topping type" and I do not know what pitch they are for nor have I measured to find out.

                      have used the standup type quite a bit.

                      I was not quite appreciating the differences between the standard "insert" and the similar looking "laydown threading insert" as far as the way they fit the holder (and. yes, the typo was no help!). Some standard have shims, but they are not angled. I have piles of regular inserts, holders, boring bars, etc and use them.
                      CNC machines only go through the motions.

                      Ideas expressed may be mine, or from anyone else in the universe.
                      Not responsible for clerical errors. Or those made by lay people either.
                      Number formats and units may be chosen at random depending on what day it is.
                      I reserve the right to use a number system with any integer base without prior notice.
                      Generalizations are understood to be "often" true, but not true in every case.

                      Comment


                      • Originally posted by J Tiers View Post
                        Those are laydown. I think I have some that came to me in a toolbox. Have not used them, IIRC they are "topping type" and I do not know what pitch they are for nor have I measured to find out.

                        have used the standup type quite a bit.

                        I was not quite appreciating the differences between the standard "insert" and the similar looking "laydown threading insert" as far as the way they fit the holder (and. yes, the typo was no help!). Some standard have shims, but they are not angled. I have piles of regular inserts, holders, boring bars, etc and use them.
                        Sorry, but I have to ask: Why do you argue about something you have no experience with and have limited knowledge of? What's the point? Do you just like to argue?

                        Comment


                        • A few pages back on this thread I posted a document link from a cutting tool supplier that showed the relationship between a thread's pitch, pitch diameter, and its helix angle. I was hoping this would help explain the interaction of those variables as a way to help the OP of this thread, and others, with some of the questions pertaining to problems encountered in his cutting technique. Unfortunately I neglected to proof read the documents, and it turns out there are some dependencies in some of the information provided. My apologies. Also, as a matter of full disclosure, I do not currently own any tooling from this supplier. I simply found that they had a wealth of information that I thought would be helpful here. After a little research I found an updated catalog from that same supplier, and it looks like they have identified and corrected those dependencies, so I'm going to risk offering a link to the revised pages: http://www.korloy.com/newkorloy/eng/..._Threading.pdf The chart in question appears on page 4 of the catalog, which is page 5 of the pdf.

                          Comment


                          • I just single point threads using a round HSS toolbit in a holder. The bit is clamped in with an Allen grub screw, and can be readily adjusted to the required angle for whatever pitch of thread I'm cutting, right hand or left hand. Similar arrangement in a boring type tool for internal threads. Works for me, avoids having loads of different inserts and avoids pages and pages of arguments about how they are used.
                            'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger

                            Comment


                            • Emphasis mine:

                              Originally posted by Richard P Wilson View Post
                              I just single point threads using a round HSS toolbit in a holder. The bit is clamped in with an Allen grub screw, and can be readily adjusted to the required angle for whatever pitch of thread I'm cutting, right hand or left hand. Similar arrangement in a boring type tool for internal threads. Works for me, avoids having loads of different inserts and avoids pages and pages of arguments about how they are used.
                              Well, I agree that it will avoid having loads of different inserts. I'll leave it at that!

                              Dan
                              At the end of the project, there is a profound difference between spare parts and left over parts.

                              Location: SF East Bay.

                              Comment


                              • Originally posted by tomato coupe View Post
                                Sorry, but I have to ask: Why do you argue about something you have no experience with and have limited knowledge of? What's the point? Do you just like to argue?
                                His grandiosity is always hard at work.

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