Checking tailstock alignment

Discussion in 'Gunsmithing' started by specweldtom, Apr 13, 2008.

  1. specweldtom

    specweldtom Well-Known Member

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    I have checked my tailstock for radial and axial misalignment several times, mostly with a Jacobs chuck on a #3 Morse taper, with a 10" length of 1/2" drill rod chucked in it. I travel the carriage with a Joeblock on it and a dial indicator reading the drill rod in the horizontal plane and then in the vertical plane.

    All that out of the way, I'm wondering if it would be worth it to turn a #3 Morse taper on a piece of 1" drill rod and stop wondering if the Jacobs chuck and #3 adapter are causing the approx .003" of deflection in the horizontal plane. I also anchor an indicator on the face of the lathe chuck and hand rotate around the drill rod and get some horizontal misalignment. I can move the tailstock horizontally and bring the end of the drill rod into perfect concentricity with the spindle, but the traveling indicator still shows angular misalignment along the length of the drill rod. The tailstock base has provision for lots of lateral offset, but nothing I can find for angular adjustment. Presumably it shouldn't need it.

    I'd like to know how you should check for perfect tailstock alignment. Am I on the right track?

    Thanks, Tom
     
  2. James Jones

    James Jones Well-Known Member

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    Tom , I'd take the chuck out and find somthig better to use like a precision dead center , or like to mentioned you can make a taper on a piece of bar and have your own indicating rod.

    One quick and dirty way is to use a piece of solid bar in the chuck and die it in , then cut a point on it. Useing a dead center in your tail stock run the dead center all the way out and make the points touch thsi should have you pertty close.

    But some chucks can be as much as .005"-.010" out
     

  3. edge

    edge Well-Known Member

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    0.0030 on a standard drill chuck is not bad at all.

    IMO, I would take the largest diameter material that you have, and as long as is usable in your machine.

    Put in a live/dead center and skim cut the stock til it cleans up round. Then measure it along its length.

    Taper can be headstock OR tailstock OR Chuck misalignment, but is can also be worn ways.
    Worn ways will almost always give you a barrel shape since the area near the headstock gets used the most.

    The tailstock generally has front to back adjustment, but no vertical adjustment.
    If you are lucky enough that the tailstock is low, it usually can be shimed depending on its design.

    edge.
     
  4. LR6mm

    LR6mm Member

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    3 thou using a Jacobs drill chuck isn't that bad. I always found the Albrecht keyless chucks to be far superior to the Jacobs, for precision work. Just don't try to power tap a hole with the Albrecht, because it doesn't have the clamping force that the Jacobs does. I have used the cheaper copies of the Albrecht, and I must say that the real deal is far better. As far as aligning up your machine, I would second what the last poster said.
     
  5. olcrip

    olcrip Well-Known Member

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    Victer tool supply has Kisser buttons. One goes in the center in the headstock and the other one goes in the center (preferably dead center) tailstock, you kiss the two buttons together. When the flat discs of the buttons align your in alignment..
     
  6. specweldtom

    specweldtom Well-Known Member

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    Thanks to all. I'm going to use the kisser buttons to check against the drill rod alignment.

    Good hunting, Tom
     
  7. edge

    edge Well-Known Member

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  8. specweldtom

    specweldtom Well-Known Member

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    Edge, been out of town for awhile. Thanks for the link.

    Tom
     
  9. Rustystud

    Rustystud Well-Known Member

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    Get/make a test bar..

    enough said.

    Rustystud
     
  10. specweldtom

    specweldtom Well-Known Member

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    Thanks Rusty, I'm going to do both. This is one place that I'm looking for perfect.

    Tom