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Headstock bigger than my barrel

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  • Headstock bigger than my barrel

    I've read with great interest the threads on which lathes are best for gunsmiths. Unfortunately, I didn't read them prior to getting my lathe so now I have an issue. The space between my chuck and the outboard side of my headstock is quite a bit longer than the length of pretty much any barrel I'm going to stick in there. I'm perfectly ok on how to make a spider, and how to set up a barrel in the spider, the problem is I have no clue how to do it with a headstock that is too long.

    Now I know what you're thinking, Dan, this is a wonderful opportunity for you to go out and buy a smaller lathe, an additional lathe, a lathe that you surely need for your type of operation. There is probably a perfectly serviceable lathe languishing on craigslist somewhere that needs a home, a family, a place where it can be loved. NO! I say, foul temptress, I will not be lured into the siren song of more tools this time, at least not till I've gotten better at using the one I have, or I have more money, or the wife goes out of town.

    So my question is, O' great and wise knowers of metal things, how can I jig something up internal to the headstock and true the outboard side of the barrel so I can then chuck up the work end of my barrel and go to making chips. I thought of an internal bushing setup, but it appears that in between the outboard side and chuck side of the headstock, the internal part isn't machined precisely. Do I make some type of extended barrel piece that I can then clamp to the barrel and true up on a traditional spider? It would seem that getting it perfectly straight would be a bear. I'm at a loss at this point, and I'm really not in the mood to blow the end off of a muzzle brake.
    Dan from Raleigh, NC

    If it's stupid but it works, it's not stupid.
    _____________________
    "What is your host's purpose for the party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have sent champagne and women over to your place by taxi." P.J. O'Rourke

  • #2
    ignore those evil voices and pursue a new lathe. or work on bigger guns

    my mind also went to a bushing, but then you do you get an indicator on the barrel to know its straight? Make an exact fitting extension on the barrel and use a spider in the regular position? turn longer than necessary barrels then cut them down? A bit lame, but all I've got on it....if you have space this is an awesome excuse for more machines
    .

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    • #3
      I imagine something that looks like an Ye (legs 120° apart). Each leg is made of two stacked wedges that can be shifted in regard to the other by some screw. That Y in fact has no connection at the center, because that's where the barrel goes. Now you push that into your spindle and with the screws perfectly center and clamp it.

      Now, don't ask me how you find out wether the left end is on center. I have no laser pointer.


      Nick

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      • #4
        How about an internal bushing with an O-ring groove on the outside for a thick O-ring to adjust for the non precise bore of the spindle. You could make the O-ring a light press fit and just slide it in and out, maybe with a little grease if desired.

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        • #5
          Originally posted by Mcgyver
          ignore those evil voices and pursue a new lathe.
          No...MUST.....RESIST.... Seriously, I'd really like to avoid another lathe. I'm particular about my shop, that it have the correct amount of room so I'm not tripping over myself. I have to pull tractors and such in there too. Of course, it is a small lathe. NO! We need a better way.

          Originally posted by Mcgyver
          my mind also went to a bushing, but then you do you get an indicator on the barrel to know its straight?
          Maybe get a precision rod to extend out of the bore so you can indicate? Of course, you couldn't make any adjustments anyway.
          Dan from Raleigh, NC

          If it's stupid but it works, it's not stupid.
          _____________________
          "What is your host's purpose for the party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have sent champagne and women over to your place by taxi." P.J. O'Rourke

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          • #6
            I made one of these that screws into the headstock spindle. Perhaps you can come up with a variation that would work on your lathe.

            It's only ink and paper

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            • #7
              Wouldn't a steady rest accomplish the task?
              The lathe is obviously big enough.
              DJ

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              • #8
                Dan

                Some turn a bushing that will just fit over the barrel and also fits closely to the inside of the spindle. (Look on the Benchrest Central forum in the Gunsmith section. Search under How to chamber a barrel. By Jackie Schmidt)

                Another way is to make something similar to a collet closer, the hand wheel type. It attaches to the left end of the spindle and has a tube that slides into the spindle. That end has a tapered point that fits into the bore.
                Again look at Benchrest centeral Search under chambering with a long headstock by Jim Borden.

                Hal

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                • #9
                  By how much is the spindle too long and how much spindle is hanging out? Maybe a mod is possible..

                  Also a 5C chuck will stick out less than the larger chucks. Maybe a combination of bobbing the spindle and using collets or collet chuck will solve your problem.

                  If you go to a smaller lathe you will more than likely get a smaller spindle ID..

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                  • #10
                    Originally posted by mechanicalmagic
                    Wouldn't a steady rest accomplish the task?
                    The lathe is obviously big enough.
                    DJ
                    I don't have a steady rest, although I guess it's possible to get one. I haven't even pursued that option because of some of the threads I've read where they say a steady rest was bad for doing barrel work. Basically the OD of the barrel doesn't necessarily align with the ID of the bore, meaning you need to true to the bore, not the barrel, which as I understand it, isn't going to be possible from a steady rest.

                    Calrd, the setup you show is exactly what I wanted to make. The problem is I have about 26 inches from the face of the 4 jaw chuck to the outboard side of the spindle on the headstock. Since the barrels are in the 20-24" range, I don't have enough barrel to reach from the chuck to the threads, much less to the adjustable portion of the spider you show.

                    I have a bushing turned that will fit into my spindle. I can cut a o-ring groove into it, that's a good idea. The problem is, how do I true it? Mount the barrel backwards in the chuck, true the barrel at the chuck, put the bushing/spider onto the barrel, then adjust the bushing with some type of spider type adjustment screws, counter bored of course, then reverse the whole deal, shove it into the spindle, and true the work end of the barrel then go to work? That was my crazy theory this weekend, but I couldn't get past the idea of slop in the bushing. The o-ring may solve that, sorta. I'm worried I'm not going to be able to hold any kind of real tolerance with all these variables because the barrel won't really by true when I true the bushing onto it. Hmm, unless I use the tail stock, true the barrel between the chuck and tail stock, then true the bushing/spider, then reverse the whole thing and hope the things stays true when I shove it in. The inside of the spindle isn't exactly smooth. It looks like it was machined rough and only the inboard and outboard sections were cleaned up. Being off 10 thou at the end of a barrel due to rough surfaces is gonna make bullets go wonky at the other end.

                    I can try it to see what happens. Worst that happens is it doesn't work. Before I do, Hal, I'm gonna check out the links you suggested, thanks.
                    Dan from Raleigh, NC

                    If it's stupid but it works, it's not stupid.
                    _____________________
                    "What is your host's purpose for the party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have sent champagne and women over to your place by taxi." P.J. O'Rourke

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                    • #11
                      Why not do your barrel work between centers? In the old days, gunsmith lathe's didn't have a spindle bore large enough for a barrel. Some smiths still use the procedure today even with big bore spindle lathes in their shops.

                      All you need is a 60 deg. center reamer with a bore size pilot( Brownells), a steady rest and your chamber reamer with holder. You can do anything that can be done in the spindle bore and to the same degree of precision. It might take a little longer, but so what?

                      RWO

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                      • #12
                        Err, the problem is theres.. work inside the headstock?

                        Just ignore it. It might whip around if its highly offset weight and weak and high rpms, but otherwise its fine. (a rag or something could be stuffed in to keep it from whiping too much if you are really worryed)

                        Iv turned 1/2" bar that stuck 2' into my headstock and it did'nt whip around at all.
                        Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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                        • #13
                          Chambering

                          Hi MrDan-
                          If you do the spider bushing on the end of the barrel as you suggested earlier and use the O-ring on the bushing, the few thou. that it may be off 2 feet away from where you're chambering will not make any difference in the accuracy of the barrel. It will be so straight that the bullets won't know the difference. It will probably be truer than 90% of all the factory barrels.

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                          • #14
                            Dan,
                            Depending on what operation you are doing this may work for you:
                            It's a bushing, as others have suggested, but it has a hole drilled in it that is the same size as the bore of the barrel. In that hole is a brass or mild steel rod that is sized to be a light press (or locktite) fit into both the bushing and the barrel. Once mounted in the spindle, it would support the other end of the barrel without regard for the outside of the barrel.

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                            • #15
                              That's a pretty good idea too, Bill D.

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