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Quick and dirty tracer lathe

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  • Quick and dirty tracer lathe

    Hi Everyone,

    Years ago I had to run a job that had a 14 inch long taper from 3/8 to 5/8 diameter. Problem was I had no taper attachment.

    Having worked in a toolroom where we had several lathes with hydraulic tracer attachments I realized I might be able to do the same thing without the hydraulics.

    I made two risers to hold a piece of flat bar at the angle I needed:





    Then with a dial indicator fastened to the crosslide I could run the machine and manually keep the needle on zero with the power feed advancing the carriage:



    I also made a follower rest and made the cut all in one pass:



    These photos are only to show how I did it. The actual parts were around twenty inches long.

    More in next post..........................................


    I've been wanting to try using the same idea to duplicate a complex shape and this Last year I made a couple of ball cranks for a friend's Elgin mill.
    Last edited by jhe.1973; 09-22-2019, 04:06 PM.
    Best wishes to ya’ll.

    Sincerely,

    Jim

    "To invent you need a good imagination and a pile of junk" - Thomas Edison

    "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

  • #2
    This shows the high tech coolant system:



    This is right after turning without any filing or other finishing:



    For the longest time I have been itching to try this with a more complex shape, such as the compound curve of a ball crank handle. Last year I got the chance.

    Here is what I came up with and it worked way beyond what I thought it would:



    I used a more sensitive indicator and a slower spindle speed than I had done with the long taper. Another view:



    Finished parts in the next post.............................
    Best wishes to ya’ll.

    Sincerely,

    Jim

    "To invent you need a good imagination and a pile of junk" - Thomas Edison

    "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

    Comment


    • #3
      All it took on the compound curves was a small amount of emery cloth while still in the lathe and the final finish came up easily with a buffer:



      The three balls and taper shaft were done in another lathe with a ball turning attachment.
      Best wishes to ya’ll.

      Sincerely,

      Jim

      "To invent you need a good imagination and a pile of junk" - Thomas Edison

      "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

      Comment


      • #4
        One more thing I just remembered, these risers can be used in the front as shown or on the rear of the bed where the template is more out of the way.
        Best wishes to ya’ll.

        Sincerely,

        Jim

        "To invent you need a good imagination and a pile of junk" - Thomas Edison

        "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

        Comment


        • #5
          That's great ingenuity but I don't know how you managed to use a follower rest on a tapered part. The rest would follow a parallel path whilst the part gets larger in diameter.
          Peter - novice home machinist, modern motorcycle enthusiast.

          Denford Viceroy 280 Synchro (11 x 24)
          Herbert 0V adapted to R8 by 'Sir John'.
          Monarch 10EE 1942

          Comment


          • #6
            looks like the follower rest is bolted to the side of the carriage, not to the cross slide.

            Comment


            • #7
              Originally posted by Peter. View Post
              That's great ingenuity but I don't know how you managed to use a follower rest on a tapered part. The rest would follow a parallel path whilst the part gets larger in diameter.
              You'd use tapered roller bearings....

              Comment


              • #8
                Originally posted by johansen View Post
                looks like the follower rest is bolted to the side of the carriage, not to the cross slide.
                Which is usual, and I just re-read the post that it was cut in one pass which explains the use of the follower. If there were multiple passes it obviously wouldn't work.
                Peter - novice home machinist, modern motorcycle enthusiast.

                Denford Viceroy 280 Synchro (11 x 24)
                Herbert 0V adapted to R8 by 'Sir John'.
                Monarch 10EE 1942

                Comment


                • #9
                  Originally posted by jhe.1973 View Post
                  ...
                  This is right after turning without any filing or other finishing:



                  ...
                  Is it me or is there a corner about a 1/4 of the way from the right? Maybe that "... manually keep[ing] the needle on zero ..." is not as easy as it sounds?

                  Comment


                  • #10
                    Here is a solution I came up with for turning long tapered and contoured parts...

                    http://bbs.homeshopmachinist.net/thr...r-Manual-Lathe

                    http://bbs.homeshopmachinist.net/thr...13#post1211213

                    Comment


                    • #11
                      For the "complex curve" that increases and decreases in diameter, did you crank the cross slide in and out on the same pass and somehow deal the backlash, or change directions and work consistently to or from the smallest diameter, or...?
                      "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

                      Comment


                      • #12
                        Pretty slick setup!
                        I just need one more tool,just one!

                        Comment


                        • #13
                          Very nice. You have a nice stiff lathe there. In this case it doesn't seem to matter. Nice fix up.

                          What happened to the company that was selling copy, tracers for small jobs?

                          I saw a set on ebay 18 years ago and didn't buy it. The design looked nice and simple. Not like a hydraulic Monarch tracer

                          Seems like it was a sheet metal afair and you would prolly just release the cross slide and do it.

                          I dont know. It looked neat. Been looking for that kit ever sense. JR
                          My old yahoo group. Bridgeport Mill Group

                          https://groups.yahoo.com/neo/groups/...port_mill/info

                          Comment


                          • #14
                            Originally posted by Bob Engelhardt View Post
                            Is it me or is there a corner about a 1/4 of the way from the right? Maybe that "... manually keep[ing] the needle on zero ..." is not as easy as it sounds?
                            I think the corner you are referring to is a detail that I failed to explain. The first 1 inch of the shafts I had to make were to be threaded 3/8-24. I had the lathe set so that I would turn that 1 inch using the cross slide and the indicator set so that the needle would be at zero at this distance from the end. Then I would start the manual tracking with the indicator.
                            Best wishes to ya’ll.

                            Sincerely,

                            Jim

                            "To invent you need a good imagination and a pile of junk" - Thomas Edison

                            "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                            Comment


                            • #15
                              Originally posted by mickeyf View Post
                              For the "complex curve" that increases and decreases in diameter, did you crank the cross slide in and out on the same pass and somehow deal the backlash, or change directions and work consistently to or from the smallest diameter, or...?
                              The multiple curves were actually easier than I thought they might be. Because the area where one curve transitions to the other direction, the needle of the .0001 indicator I used would become noticeably easier to keep on zero and it would hover for a moment. This was a signal to quickly take up the backlash in the opposite direction.

                              I should mention that it wasn't possible to keep the needle precisely on zero all the time, but with the more sensitive indicator, a few tenths either way had little effect on the finished part.

                              One thing that occurred to me was that the ideal setup would be to have a carriage power feed run with a variable speed DC motor. That way the power feed would be independent of the spindle speed. If I could slow the carriage to a crawl, it would become downright simple to keep it following a template. I could also use a higher spindle speed for an even better finish.

                              Oh.................thanks to you all for your kind words!
                              Last edited by jhe.1973; 09-23-2019, 02:14 AM. Reason: Forgot to say thanks
                              Best wishes to ya’ll.

                              Sincerely,

                              Jim

                              "To invent you need a good imagination and a pile of junk" - Thomas Edison

                              "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                              Comment

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