Tailstock Bore

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  • bhjones
    Senior Member
    • Jan 2006
    • 356

    Tailstock Bore

    I'm curios if anyone here has dealt with a sloppy bore in a tailstock?

    I have some slop in the tailstock of a 12" Craftsman I'm refurbishing. My first thought is to bore the hole then bush and hone it. I've also found something on PM about boring the tailstock then hard chroming the ram and having it ground.

    Any thoughts?
    Brett Jones...
  • rkepler
    Senior Member
    • Mar 2005
    • 1013

    #2
    A lot can go wrong on a tailstock, so it's best to check everything possible before deciding on how to fix it - the tailstock could have worn on the base unevenly and have a tilt or nod (or both), the bore could be a lot more worn towards the front than the rear (typical for the use) and most of the time the wear makes the hole egg shaped. It's best to correct the tilt and or nod by grinding or scraping the bottom of the base (and damn near trivial on the Atlas) and then to shim between the base and top casting to center the bore.

    Once that's done you want to see how far off the bore is - if it's not too bad you likely can fit a new quill made from oversize stock. Only if the wear on the tailstock casting is severe you might consider boring, and after the other changes it'll be a fairly minor amount to take out. After that you might consider having the quill hard chromed and ground to match the honed tailstock.

    If you don't fix the other problems you'll end up boring a lot more material from the casting. In that case you'll almost have to make a quill as adding more than .005" diameter in chrome will cost too much to be practical (at least as I recall, I haven't cost something like that lately).

    Comment

    • Rich Carlstedt
      Senior Member
      • Jul 2001
      • 5485

      #3
      Chrome is nice, but too many operations.
      after chrome, you need to grind it "using" the Morse Taper as your guide $$$$
      and if you want a .005 thickness, some parts will be at .020 !

      Better method is to have the spindle 'Electroless Nickel" (EC) plated, and have them "Mask" the taper and the threads. That way, only the OD and faces will be plated.
      EC is Totally even , so no grinding required like chrome, and because it is even, you never loose the tapers center. If you ask for .001, you get thatt thickness on every plated surface
      Also if you hone the bore to say .003 over stock, the EC plater can laydown
      a coating of .0014 which would give you a nice fit, without any rework.
      Ask for "High Phosphorus" coating (9 to 13 %) to get a really hard finish.
      Also ask for a two hour postbake to eliminate hydrogen embrittlement, which can cause flaking if not done. ..Those high gloss finishes do not wear as well as the high phos coatings.
      Your quill before plating must be spotless clean !

      Rich
      Green Bay, WI

      Comment

      • J. R. Williams
        Senior Member
        • Aug 2003
        • 874

        #4
        Tailstock

        Consider shopping around to pick up a better tailstock or part out the existing unit and buy another lathe. Bore out the tailstock and fabricate another quill will work if you have plenty of time and access to equiment.

        JRW

        Comment

        • wierdscience
          Senior Member
          • Jan 2003
          • 22085

          #5
          I have heard of building them up by metalizing spray and then grinding.It would depend on the amount of wear..003" then platling would work,something like .010" then I would metalize and grind.
          I just need one more tool,just one!

          Comment

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