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Long skinny threading

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  • #16
    How about buying some Jorgensen clamps on ebay and just keeping the screws.

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    • #17
      If I recall, the specialty woodcraft stores sell screw sets for making ones own clamps... just add the wood jaws.

      Joe B

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      • #18
        To start with I have done a lot of sinle point threading, dontvrecall ever having used a follow rest.
        one tine i cut a 1/2 thread on s shaft and it was lets say 18 inches long or longer, tell you what i did,
        cut the whole shaft till test nut fit one end with a bit of clearance . of course that would mean both ends.
        Then I marked the area or part of the area that nut would not go over. Maybe with masking tape? Then using the final cut number from before, i increased the cut in small steps over a few inches, you can see if its cutting much or not.. then work along like that till nut starts to fit.
        on a long thread that is all yhe same hand you can use a second nut. It may not be uber consistent, but Hey It Works..

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        • #19
          Originally posted by Dan Krager View Post
          I had dismissed the notion of making the screws in two parts joined in the middle because I have never seen LH all thread. It really exists? I could easily weld two pieces together and turn the weld down.
          s.
          in your choice of flavours, and it'll be there the next day. What an age we live in!

          https://www.mcmaster.com/threaded-ro...ion~left-hand/
          in Toronto Ontario - where are you?

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          • #20
            Originally posted by Richard P Wilson View Post
            Lucky, lucky people! I could grow old and die here in the UK trying to source small quantities of stainless left hand and right hand Acme allthread, but to you guys its no problem at all.
            Yeah, it really is nice living in a country where we are citizens, not subjects.

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            • #21
              Originally posted by Dan Krager View Post
              I had dismissed the notion of making the screws in two parts joined in the middle because I have never seen LH all thread. It really exists?
              .
              You've received some great suggestions here. As to the purchase of left hand threaded rod here's a link to a known reputable supplier of all sorts of good things:

              https://www.mcmaster.com/Threaded-Ro...readed-rods-9/

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              • #22
                Here's a source for both RH and LH ACME screw all thread, in many different metals:

                https://www.roton.com/products/acme-...ineering-data/

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                • #23
                  Originally posted by Mcgyver View Post

                  in your choice of flavours, and it'll be there the next day. What an age we live in!

                  https://www.mcmaster.com/threaded-ro...ion~left-hand/
                  Did you notice the oddball threads that it's available in? E.g., 3/8-10 & 12. 'Never heard of 3/8-10 & 12, but they have it in LH !

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                  • #24
                    Originally posted by Bob Engelhardt View Post

                    Did you notice the oddball threads that it's available in? E.g., 3/8-10 & 12. 'Never heard of 3/8-10 & 12, but they have it in LH !
                    I didn't. The 10 sounds useful, hundred thou to the revolution. I confess I'm ignorant on acme TPI standards. I mean I've made a number of them, but its always been follow the leader, replacing some existing part vs design. i.e. the tpi was set going in.

                    Left hand acmes are used on a lot of machine feedscrews (maybe also HD turnbuckles?) so I'm not that surprised there's a lot of LH stuff available
                    in Toronto Ontario - where are you?

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                    • #25
                      Thank you all for the greatly helpful posts. I found the McMaster Carr stuff and will strongly consider ordering from them when I get to where I need more material.

                      I'm confused about the references to ACME threads. I thought, perhaps mistakenly, that ACME threads (in U.S.A) were in the family of square threads. ???? I've never seen square threads on these woodworking hand screws. I must be missing something.

                      Anyway, I've tried to secure the blank rod in a brand new 6" 3 jaw chuck on my Smithy and spin it slowly in reverse while hand holding the LH die stock. I was excited at first that I could actually hold the stock from turning (I had started it by hand) until I realized that the rod blank was spinning in the chuck! Grrrr.. I horsed the chuck key in all three locations again, gained a pittance, and it still slipped. I didn't mess around with it further even though it would save a LOT of time and seemed to have the power to do the job. Nor did I proceed to set up for "precutting" the threads on the lathe for finishing by hand.

                      I took the round die out of the nice hex stock with chrome plated (ooooh look at the shiny object) ratcheting handles and put it in the underbuilt cheap round stock with bent handles with three set screws. By putting the middle screw in the V at the split and tightening all screws as far as their stripped threads would allow, I set the adjustable guide firmly to the rod and proceeded to try again, determined to do 32 half rounds before I expired. To my great surprise, it took about half the effort compared to the previous try and the chips peeled out cleanly leaving very adequate threads. I tested the fit and it's a bit tight, but that can be easily fixed with a powered rod holder (lathe or hand drill) to run the die back and forth after a small adjustment. So I was happy with that success and learned something from it. Now that doesn't mean I will never put a round die in a hex stock, but I will be sure to pay attention to how it's done and add set screws if needed.

                      Some cheater handles ease the pressure on hands and it is going well enough to continue a bit at a time until I can figure out a powered solution.

                      DanK
                      You may only view thumbnails in this gallery. This gallery has 2 photos.
                      DanK

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                      • #26
                        Acme threads have a 55 degree angle between the faces, metric trapezoidal threads are 60 degrees. The profiles on each are thicker than UNC or standard metric threads.

                        https://www.rr-99.top/products.aspx?...e+thread&cid=6
                        elf
                        Senior Member
                        Last edited by elf; 09-23-2021, 08:28 PM.

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                        • #27
                          Originally posted by elf View Post
                          Acme threads have a 55 degree angle between the faces, metric trapezoidal threads are 60 degrees. The profiles on each are thicker than UNC or standard metric threads.

                          https://www.rr-99.top/products.aspx?...e+thread&cid=6
                          acme are 29, I think you're thinking whitworth which is 55
                          in Toronto Ontario - where are you?

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                          • #28
                            Acme threads have a 55 degree angle between the faces,


                            55 degrees? This is news to me. Even the link you provided shows different. Only thread I ever heard of that was 55 degree was Withworth, and we don't generally see those on this side of the pond.


                            "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

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                            • #29
                              Originally posted by Mcgyver View Post

                              acme are 29, I think you're thinking whitworth which is 55
                              Sorry, I wasn't paying attention

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                              • #30
                                In the lathe with a follower rest, single point. Why is this a point of contention?

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