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Making Screws Quickly

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  • Making Screws Quickly

    This thread is in response to another thread called "Fixing Up Turret Tooling " that has many facets of turning capability, but one of the needs is making screws of various forms.
    I built a form of box tool many years ago when I was faced with making many many screws, both square and hex head and in a manual lathe . A totally boring job.
    A good friend in Indiana showed me his work and I improved on it and the result is the following tool which I will describe here.
    I was going to write an article for Home Shop Machinist Magazine, our loyal supporters for this website, but never got a round to it.
    So maybe with these pictures it can help someone as I describe the tool. the tool will make screws in seconds and be very repeatable

    Basically, The tool can be mounted in either a tailstock or an Aloris Style Tool Post
    The advantage of the tailstock is that the screw can be parted off immediately
    The advantage of the Aloris mount is more rigidity , which is needed for larger diameter screws < .25
    A typical run takes maybe 10-15 seconds for a completed hex or square head screw

    So first the pictures, then the process
    Click image for larger version

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    The work piece diameter is unique to the Work Bushing , The bushing can accept round, hex, or square stock as long as there is a sliding fit !
    I make extra bushings with a 1/8 hole and then drill them out as needed to match the diagonal size for hex/square stock, or the Diameter (+.0005) for round stock.
    The Bushing turns freely in the Box Tool Body and is retained by a set screw from coming out when the work is retracted.

    Click image for larger version

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    The Tool Bit is always on Center where the Cut Edge matches the work piece center-line.
    For Thread Diameter settings, I introduce a Depth Mike into a hole that exactly matches the HSS tool cutting point
    and I record the setting for future use. So you loosen the tool clamp and slide the tool into the depth mike (preset) and clamp and done !
    For first run stock do a rough setting, make a cut and measure and that tells you how much more to set the mike.
    No fiddling with tool clamping over and over
    Click image for larger version

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    Here are some bushings of various sizes . Note the bushings have a relief grove that the retaining set screw rides in ( but does not clamp !)
    Note the bushing for square stock to be used in a 3 jaw chuck
    Note the square stock in a Square broached bushing, which I found is not needed ( nice, but not necessary) If the raw material ( I use Ground Key Stock ) is
    precise, the stock will be supported by a round hole as long as it is on the snug side , and eliminates making broached bushings.

    Click image for larger version

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    What you see above is what I call "Sticks" . If I decide to not part-off in the lathe and need large quantities, I use multiple sticks ( start at 6") and do both ends
    as seen here above and then a second operation is needed later.
    below are my Die Holders , a generous size and knurled for gripping when needed
    Click image for larger version

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    The Die holder is bored on one side for a running fit on the Box Tool Body "Boss' and the other side is made for whatever size dies you use.
    The two here are for 5/8 and 1" I believe

    The operation goes like this:
    Extend the work piece from the chuck and start the lathe. if you intend to part off, calculate the exposure to keep the stock close to the chuck
    Feed in the Box Tool- I actually slide the tailstock on the ways for smaller screws so my cutoff tool never changes X location .
    Anyway, feed the Box tool in until the stop prevents movement .
    Immediately retract the Box tool to about 2 inches of clearance and mount the die holder in the Bossl WITHOUT stopping the lathe
    and then feed the Box tool back into the work, the die will start turning when it starts its cut, and you hold the knurl as needed to thread
    Since the Boss is about 1/4" deep, it will start the thread straight and you can hold it until it is threaded and have your hand on the F/R Switch and move the Boxtoll back and go into reverse to un-thread the die . Part if needed. For small screws, I do not recommend a fast spindle speed as the die is unsupported
    I'll post another picture of the die mounted to the tool next

    Rich
    PS
    For Tailstock mounting, I recommend a very rigid clamp on the depth setting and you could add a lock nut as well
    The clamp I have is very strong in that respect.
    Green Bay, WI

  • #2
    Box Tool with Die Bushing Mounted
    Rich
    Click image for larger version

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    Green Bay, WI

    Comment


    • #3
      So the first push in cuts to size, and the second is with the die to thread....

      Not bad, if you have neither a bed turret nor a tailstock turret.

      For some threads, holding by hand is not so easy, but a couple easy modifications could take care of that problem easily.

      I see a bar down to ride the bed (possibly the side of the tailstock flat way) to prevent the box tool from spinning, and a short lug on the front that goes into a hole on the back of the die holder, so the die is held against spinning, but releases at the right point, and you do not need to hold it.
      3751 6193 2700 3517

      Keep eye on ball.
      Hashim Khan

      If you look closely at a digital signal, you find out it is really analog......

      Comment


      • #4
        Good points Jerry !
        The bigger the Die holders, the easier to hold, but I do mostly fine threads so the load is not too great

        Rich
        Green Bay, WI

        Comment


        • #5
          The proper way to make screws is like this:

          https://www.youtube.com/watch?v=gr4aN23XGz0

          About 55 seconds, not rushed, to make a complete brass thumbscrew.

          Doc.
          Doc's Machine. (Probably not what you expect.)

          Comment


          • #6
            Originally posted by Doc Nickel View Post
            The proper way to make screws is like this:

            https://www.youtube.com/watch?v=gr4aN23XGz0

            About 55 seconds, not rushed, to make a complete brass thumbscrew.

            Doc.
            If only we were all fortunate enough to own turret lathes with geometric threading heads and a full set of dies

            Comment


            • #7
              You can get tailstock turrets for not a "ton" of money. There was a place selling plans or kits for bed turrets to fit Atlas, etc.

              The geometric head would be good, though, no reversing. I have a similar head and a bunch of dies, but it is really hard to adapt to a turret use, and I have not figured out just how to do it yet.
              3751 6193 2700 3517

              Keep eye on ball.
              Hashim Khan

              If you look closely at a digital signal, you find out it is really analog......

              Comment


              • #8
                An outfit called Down River Tools is the one that had plan sets for turrets, but unfortunately they seem to have gone away.

                Comment


                • #9
                  Originally posted by [email protected] View Post
                  An outfit called Down River Tools is the one that had plan sets for turrets, but unfortunately they seem to have gone away.
                  Sorry to hear that...Good vendor !

                  Rich
                  Green Bay, WI

                  Comment


                  • #10
                    Originally posted by [email protected] View Post
                    An outfit called Down River Tools is the one that had plan sets for turrets, but unfortunately they seem to have gone away.
                    Yep, the website is gone, the Youtube remains.
                    3751 6193 2700 3517

                    Keep eye on ball.
                    Hashim Khan

                    If you look closely at a digital signal, you find out it is really analog......

                    Comment


                    • #11
                      Originally posted by epicfail48 View Post

                      If only we were all fortunate enough to own turret lathes with geometric threading heads and a full set of dies
                      You can Brown and Sharpe screw machines and tooling for not much money. You only need the desire. The auction of the G. Forbes shop in Pa. a week ago was proof of that: fully manual, #00, 0 2, and Ultramatics went for cheap. So did dozens o boxes of mixed tooling for them.

                      Comment


                      • #12
                        Then you've got to move them, then you've got to have room for them. I like Rich's attachment, probably make one for myself.
                        '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


                        • #13
                          Hi Rich,

                          Fantastic tool and right up. I say you copy this post to George and maybe a few pictures and let him have it for a future article, I for one would like to have that article and will plan on making one, but posted here they tend to get berried and I don't always remember where to look when I get around to that specific project, where the magazine sits in my library and I can reference it at any time for any given reason. Thanks Village Press for the magazines.

                          I say go for it and Publish. !

                          TX
                          Mr fixit for the family
                          Chris

                          Comment


                          • #14
                            Originally posted by J Tiers View Post
                            You can get tailstock turrets for not a "ton" of money. There was a place selling plans or kits for bed turrets to fit Atlas, etc.

                            The geometric head would be good, though, no reversing. I have a similar head and a bunch of dies, but it is really hard to adapt to a turret use, and I have not figured out just how to do it yet.
                            Not sure what you have trouble with. . I used to thread 3/8 -rod all day long on a turret lathe, 200 or 400 threads in a shift.. worked well but you need to be able to sharpen dies.

                            Comment


                            • #15
                              Originally posted by J Tiers View Post
                              The geometric head would be good, though, no reversing. I have a similar head and a bunch of dies, but it is really hard to adapt to a turret use, and I have not figured out just how to do it yet.
                              What do you mean, no reverse? The die head trips open when you've reach the depth you have set. Just retract and reset the head.

                              Comment

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