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Large diameter pipe tailstock support?

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  • Large diameter pipe tailstock support?

    Any tricks or tools for supporting large diameter pipe >4" in a medium-size 11x24 lathe?
    My fixed steady won't fit 4" pipe and I have used plastic plug supported with smaller tube inside the 4" and pressed on with live center.
    Sort of works but need to turn new plug for every pipe.
    Pipe live centers of this size are rare in MT3 size.

    Live 3-jaw chuck on tailstock?
    Might even let me face the end of the pipe if I would use small 2" or 3" 3-jaw chuck?
    Which would be actually a huge bonus if it works!


  • #2
    You could get a small chuck and bore the center or make a backing plate that is a press fit on the straight part of a live center. Bore it with a step in the hole that contacts the tapered part so the chuck can't get pushed back too far. Then you would have a live tailstock chuck that would go inside the pipe for cheap.

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    • #3
      Originally posted by Toolguy View Post
      You could get a small chuck and bore the center or make a backing plate that is a press fit on the straight part of a live center. Bore it with a step in the hole that contacts the tapered part so the chuck can't get pushed back too far. Then you would have a live tailstock chuck that would go inside the pipe for cheap.
      That sounds like a good idea. I saw some small chucks with M14 thread mount and was thinking of turning M14 thread to one of my crappy "import" live centers but your solution sounds even easier.

      Also just came to my mind that maybe I could use sort of "spider" what gunsmithing folks use, just internal. IE piece of 2" round stock with holes tapped radially. Insert inside the large tubing and fiddle all the screws tight.

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      • #4
        I once had to turn a piece of aluminium tube (a crossmember from the skids of a Bell 47, about 2 3/4" od by 3/8" wall) which turned out slightly bent, from a terminal heavy landing. I had assumed it was straight and was very disappointed, but had nothing else for the job. I cut it to length and filed the ends as square as possible and made a flanged plug with a centre in it. The tube was about 17" long, right at the limits of a Smart & Brown model A with a chuck, as it can just manage 21" between centres. I turned the right hand end over the last 3" to clean up and then repeated the process, with the other end. The ends were close enough in line for my purposes, and the curved centre section didn't matter. Fortunately, the parts which were to be fitted over the ends of the tube hadn't been bored at that stage.

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        • #5
          Originally posted by MattiJ View Post

          Also just came to my mind that maybe I could use sort of "spider" what gunsmithing folks use, just internal. IE piece of 2" round stock with holes tapped radially. Insert inside the large tubing and fiddle all the screws tight.
          Yes, go with the spider. Attach a piece of bar stock, one inch diameter or what have you, to a three spoke backing plate that fits between the jaws of the chuck. Support the other end of the bar stock and spider with a regular live center in the tail stock. A little pressure from the tail stock and the whole issue is quite rigid.

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          • #6
            I just use a bull nose live center, they're intended for this job. Not sure why you'd think they aren't available for MT3, there are lots of them out there. Here's an example (just a random amazon link, I didn't pick this one specificially). If you work with larger pipe or tubing, these are a worthwhile tool to have.

            https://www.amazon.com/LC-P3A-Morse-.../dp/B00095VUBO

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            • #7
              Originally posted by Yondering View Post
              I just use a bull nose live center, they're intended for this job. Not sure why you'd think they aren't available for MT3, there are lots of them out there. Here's an example (just a random amazon link, I didn't pick this one specificially). If you work with larger pipe or tubing, these are a worthwhile tool to have.

              https://www.amazon.com/LC-P3A-Morse-.../dp/B00095VUBO
              Umm, your link shows 3" diameter bull nose and I was interested in pipes OVER 4" diameter

              Yes, I could make my own 5" bull nose too..

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              • #8
                I have turned up temporary slip fit/tap in "plugs" for the end of the pipe in which I would pilot a hole for a normal live center.
                Andy

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                • #9
                  Interchangeable head bullnose setup would be what you're looking for. HERE IS A LINK to a "system" that uses a low angle taper to accept interchangeable bullnose heads. The write up says 3.3 to 13.5 inches is handled in the basic kit and larger sizes can be had on demand.

                  Or do you want a home shop made solution? If that's the case buy a live center you can service easily and remove the pointy bit and makeup a new center part which has a longer but still self releasing taper. then make your own bullnose heads from suitable materials.

                  I rather like the idea though of a plate with screws that we set to fit inside. With a dial gauge it would be pretty fast work to set the screw heads to the correct spacing. But with the right sort of setup it would avoid the need for facing the end of the pipe being worked on. And it would only take a couple of sizes to cover quite a range.

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                  • #10
                    Google image search 'homemade steady rest'. Lots of iterations, including make it extremes from youtube. Some elaborate, some quick n dirty.
                    I've been working on one I need to wrap up.

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                    • #11
                      I made a reasonable pipe center, by turning a center recess in a large piece of round stock, making the recess big enough to swallow nearly all of the live center's cone.

                      Then turning the reverse to a conical shape produced a "center" that could be added to the existing center to become a "pipe center". With nearly the whole live center cone inside the added part, it was quite stable.

                      Not my idea, I read it somewhere, but I have forgotten where.
                      1601

                      Keep eye on ball.
                      Hashim Khan

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                      • #12
                        The 11 x 20 Standard Modern lathe I purchased a few years ago did not come with a steady rest so I got the casting kit from MLA. It can handle 6" diameter tube (wouldn't be too comfortable with a solid bar of that size). It is designed around a 9" swing lathe so I added a rising block. It was a fun project - I have added bronze rubbing pads since this photo was taken.




                        For reference the chuck is 5" diameter.

                        Geoff
                        Last edited by ammcoman2; 11-08-2018, 06:49 PM.

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                        • #13
                          Bullnose centers wouldn't allow facing the ends. How would you adjust the screws in an internal spider? It seems to me the easy way is a scroll chuck that would run true when you tighten it.

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                          • #14
                            Originally posted by Toolguy View Post
                            Bullnose centers wouldn't allow facing the ends. How would you adjust the screws in an internal spider? It seems to me the easy way is a scroll chuck that would run true when you tighten it.
                            Small scroll chuck is easier than spider without a doubt.

                            As for adjusting the internal spider screws: shouldn't be too difficult to fit in a small open-end wrench to turn from hex "body" on the screw. You can tighten the screws only about quarter turn at a time but you shouldn't need much tghtening after finger-tight.

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                            • #15
                              Originally posted by MattiJ View Post
                              As for adjusting the internal spider screws: shouldn't be too difficult to fit in a small open-end wrench to turn from hex "body" on the screw. You can tighten the screws only about quarter turn at a time but you shouldn't need much tghtening after finger-tight.
                              I've made mine with four screws and some with six. On thin wall tubing the more contact points the better. You're right, not much more than hand tight will hold the tube in place. I use hex head screws, with the heads filed to a somewhat spherical crown. I've also incorporated the screws into a spider for the backing plate at the chuck end when using outside jaws. This helps control distortion on thin wall tubes, especially if a six jaw chuck is not available.

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