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  • Swing threading tool

    [EDIT] This idea was originally by Mike Cox, then picked up by John Moore, John did give credit to Mike Cox, I missed it, my mistake.

    First off let me give credit where it is due as the design concept came from John Moore over in the UK, my only input was suggesting the use of a key to locate the tool.

    John's initial design was for a swinging holder to hold a replaceable brazed tip tool.

    I cheated and used the tool as the swinging element.

    I have some spare blank holders for my quick change system on the lathe, some full ones and some narrow ones for things like parting blade holders.



    The one in the foreground was made as a threading tool and it works but in practice if you need a tailstock centre you can't get close enough so I was going to use John's design and this threading tool but then after a sort out I found a big old brazed tip tool and decided to use this as both the tool and the swinging holder.

    The tool was accurately marked out for the pivot hole and then drilled thru into the holder and tapped.



    It was then turned upside down and again accurately marked out for the location key to fit.



    The tool was bored out and a brass bush fitted that extended by about 5 thou and a keep plate was screwed to the bottom, again with a 5 thou shim fitted whilst drilling and tapping the holes.



    End of first post because of 4 picture limit, please don't reply until second post appears to keep continuity.

    .
    Last edited by John Stevenson; 12-23-2009, 08:00 PM. Reason: Give credit to Mike Cox.
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.




  • #2
    Second post.

    Two more pics of the finished tool, this took literally 1 1/2 hours to make but I did have the holder already done, no drawings, just typical weld it where it touches and no microns were harmed in the making of this tool.







    In use you turn a run out groove at the end of the thread and when the tool gets into this you just reverse the machine with the cross slide untouched.

    You would think that it would tear the thread but what happens is that it lifts and runs back down the thread out of the cut.
    You can even put the new cut on as you are going backwards !!

    Then select forward and do the next cut.

    Video here. http://www.youtube.com/watch?v=2F_AVx_JRlE&feature=related

    And shot of the finished thread .



    This was 2mm pitch, [ about 13 tpi ] cut at 135 rpm.

    OK done now, flames, bricks etc but it was the fastest thread I have ever cut.

    .
    Last edited by John Stevenson; 01-14-2011, 03:57 PM.
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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    • #3
      Very cool, I like how you left it free to swing up a LOT, the other tool posted here looked like it would fail to lift up enough on large diamiters with low TPI's

      Crazy backwards QCTP system.
      Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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      • #4
        Terrific! My only question is "Why doesn't everybody do it that way?"

        That's the same question I asked when I first encountered the Hardinge HLV threading system. The instructions for my Hardinge clone say "please do not thread above 1000 RPM." At first I thought it was a bit silly, but once you have a nice mechanical system like that, you can really rip.
        Cheers,

        Frank Ford
        HomeShopTech

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        • #5
          That is just soooo kewl, I love it!

          The brazed tip tool -- did you get the thread profile by regrinding a common existing profile (using carefully marked out dimensions of course!!) or -- how did you get it?
          If everything seems to be going well, you have obviously overlooked something........

          Comment


          • #6
            Originally posted by Frank Ford
            Terrific! My only question is "Why doesn't everybody do it that way?"
            Well... this is Bogstandard's design, that we discussed last week -- he was trying to replicate Martin Cleeves' swing toolholder with a much simpler design:




            With Bogstandard's design, you have to reverse the spindle to lift the threading tool out of the cut. A bit of a kludge, IMHO.
            The Hardinge flying dog clutch and the retracting toolpost is the ultimate answer, but how many actually have that?

            John's thread looks superb, obviously, but John could cut a good thread with a plastic fork
            Last edited by lazlo; 12-23-2009, 11:32 AM.
            "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

            Comment


            • #7
              No criticism from me, but I am curious how well it does with a left hand thread. I realize that is the purpose of the lug and slot so left hand threading was a design consideration.

              What is the concern level for trapping swarf under the cutter?

              Comment


              • #8
                I really like this setup. Who wouldn't? My question is what is the best method of adding a responsive brake to a lathe without one?
                Paul

                Comment


                • #9
                  Originally posted by dp
                  No criticism from me, but I am curious how well it does with a left hand thread. I realize that is the purpose of the lug and slot so left hand threading was a design consideration.

                  What is the concern level for trapping swarf under the cutter?
                  Since the key/lug in the bottom takes up the cutting force equally in each direction, I would think that LH threads would work just as well. A piece of carboard or the back of a note tablet with an X cut into it, placed over the bit and bent back over the top of the assembly would do a pretty good job of keeping the chips out of the works.

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                  • #10
                    I wonder would it work without the key?
                    "...do you not think you have enough machines?"

                    Comment


                    • #11
                      John
                      Nice work.
                      I think I can fit one on the outside of a toolblock that I am using now.
                      Almost as fast as CNC
                      e2die
                      ps Merry Xmas. You do still have Xmas in the UK?!
                      please visit my webpage:
                      http://motorworks88.webs.com/

                      Comment


                      • #12
                        Nice going

                        Nice thinking and nice job too John.

                        It actually gets better and better as there is no need for a threading dial either so it will work whether the thread is left or right-handed or an inch or metric thread on either an inch or metric lathe with no having to retract or (re)set the tool depth.

                        It seems that all bases are covered.

                        Comment


                        • #13
                          I like it. Thanks John Moore and John Sir.

                          Made it today's project. First had to make insert holder for a box of inserts that had but no holder for.

                          For the swing tool milled out a little on tool holder for clearance to swing.
                          Drilled thru insert holder and tool holder. Reamed tool holder for 1/4 press fit and reamed insert holder for slip fit and drove 1/4 dowel pin into tool holder.

                          Took advantage of the little bit left of the front set screw hole. Drilled a 1/8 hole in 5/16 socket head screw held in lathe chuck.

                          Placed insert holder in tool holder and screwed in the drilled socket head screw. Using socket head screw as drill guide, drilled thru insert holder and bottom of tool holder.

                          With needle files and Dremel tool made hole in insert holder elongated for up down movement.

                          Silver brazed 1/8 hunk of high speed steel from broken long center drill that had on hand into the 5/16 socket head screw.

                          Gave it a try, Wow that is neat. Hard part is not disengaging half nut.





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                          • #14
                            Is the slight floppiness an issue?

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                            • #15
                              Originally posted by Timewarp
                              I really like this setup. Who wouldn't? My question is what is the best method of adding a responsive brake to a lathe without one?
                              Paul
                              a VFD would be a good option! Not super fast stop, but pertty close with a good braking resistors. I wonder if some VFD's can slam it into reverse a little to incress braking power.
                              Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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