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  • lathe abuse

    There is apparently no limit to the abuse performed by my lathe's previous owner.

    While fitting the AXA toolpost on I took the cross slide and compound apart. The bolts holding the compound in position had been turned to a point. The points did what you see in these images.

    Nice one, Einstein

    I'm not sure the conic is removable. How should I repair this? I'm leaning towards filling the divots with JB Weld and filing it smooth. Then I'll make proper... thingies ... that can be driven against the conic.

    Any other ideas?

  • #2
    Bummer,don't think the JB will work,brass brazing might followed by some careful file work.
    I just need one more tool,just one!

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    • #3
      Can that conic stand being enlarged by say .050 on its surface? If that is something agreeable to the mechanics of that assembly, then you could jb weld a shim all around, which will curve over all the divots and make them disappear. Of course this shim is going to be arc-shaped, and you would have to generate the proper curve in some sheet steel to make that out of. Essentially, you wind up with a fresh surface, with the diameter being a bit larger, but the angle unchanged. Just an idea.
      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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      • #4
        Originally posted by darryl
        you could jb weld a shim all around, which will curve over all the divots and make them disappear. Of course this shim is going to be arc-shaped, and you would have to generate the proper curve in some sheet steel to make that out of.
        Welding a steel shim to dirty, old cast iron. Shudder.

        I'd try Darin's idea of brazing it. Make sure to preheat and slowly cool it -- you only get one chance...
        "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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        • #5
          A good TIG welder could fix it right up using soft Ni Cad rod without the flux. Preheating and cooling slow is the tricky part.
          It's only ink and paper

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          • #6
            I second the brazing idea!

            Brazing is way easier than many think... it just takes patience for the metal to get to temperature. The end result will be almost as hard as the main metal. Of course you'll need to find another lathe to turn, reshape and clean the excess metal created by brazing.

            Comment


            • #7
              If the divots are not too deep, could you do a light skim and make up slightly longer brass thingys?

              Michael

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              • #8
                I had an Atlas (waaaaay back) with a similar compound mount and similar issues with it. I can't remember now exactly, but I think on the Atlas it was a bolt-on affair which would be easy to remove/replace. Either that or I just don't remember milling it off.

                At any rate, I turned my own replacement and case-hardened the crap out of it. The new one sure worked tons better than the original.

                You could look it over and see if there's clearance there or enough metal to counterbore for a nut or bolt head on the backside so things don't go bump. I'd much rather make a replacement and fit it than try brazing, epoxy, welding or any of that. The spud itself is easy to make. Mill the old one off and turn or mill a recess to locate the new one (a light press fit might help here). Using two or three bolts to attach it might be more stable (i.e. less prone to spin loose or something) than one bolt/nut in the center. Any kind of steel will be better than what you've got there, and harder steel will last longer if you have any around.

                Just another option to chew on.
                Last edited by tyrone shewlaces; 05-07-2010, 11:40 PM.

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                • #9
                  It looks as if the divots are small enough that a proper angled brass wedge would bridge over them...

                  have you tried just making the brass parts and using it?

                  I don't like the idea of trying to braze it up, or Ni rod it, etc, might mess up and warp the whole crosslide. That would get you in a lot of trouble you don't want.

                  Another option is what I think was suggested.... mill that damaged part off and put in a steel replacement. You might still need to touch up the scraping, but it seems as if that would be less likely to do bigger damage.
                  1601

                  Keep eye on ball.
                  Hashim Khan

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                  • #10
                    Milling it off and bolting a turned replacement back in with something like 4 counterbored SHCS to keep it from rotating (and allow ease of shiming underneath) might do the trick nicely, with little chance of distortion. Could turn the replacement part before you mill the chunk off your lathe.
                    Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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                    • #11
                      That is nothing, on one of my lathes one of the previous owners ripped the entire compound slide off the cross slide... And this a 4300lb 17" lathe..
                      Precision takes time.

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                      • #12
                        What kind of lathe and what part is it...I pretty sure I have a base to SB 9" Compound somewhere

                        Walt
                        Walt

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                        • #13
                          Originally posted by J Tiers
                          It looks as if the divots are small enough that a proper angled brass wedge would bridge over them...

                          have you tried just making the brass parts and using it?

                          I don't like the idea of trying to braze it up, or Ni rod it, etc, might mess up and warp the whole crosslide. That would get you in a lot of trouble you don't want.

                          Another option is what I think was suggested.... mill that damaged part off and put in a steel replacement. You might still need to touch up the scraping, but it seems as if that would be less likely to do bigger damage.
                          I agree with Jerry. Except that I would use case hardened steel tapered pins for the locking pins. This is what the original items were. They will be wide enough to bridge the goobers and lock the compound in place. Brass or softer pins can deform from the indentations and be difficult to move.
                          Jim H.

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                          • #14
                            alcova, it's a Craftsman 12".

                            There are some good ideas here. I don't weld so those options are less attractive. Machining the whole thing off is an idea. I double-checked and this one is permanent. I can't imagine it was machined on the compound but who knows. There's a hole in the top, I'd be surprised if it weren't pressed on.

                            I was thinking of JB Welding the divots so a brass pin wouldn't be embossed and otherwise boogered.

                            I found one or two compounds on ebay too. A/C parts are getting expensive now - far more than they were last I looked, about 2 years ago.

                            The locking pins are beveled to match the conic of course, but do they also have an arc in them? When doing maintenance, how does one remove the locking pins which are at the bottom of a hole?

                            Comment


                            • #15
                              Tony, I don't think the original pins were brass. It's been a long time since I took a compound off but the best I can remember they were steel and could be removed with a magnet. I think all I ever did was wobble the compound around as I lifted it off to work the pins back into the holes.

                              I wouldn't use brass and they don't need a radius on the bevel.
                              It's only ink and paper

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