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Leveling a lathe

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  • Leveling a lathe

    I picked up a little 10" Sheldon and would like to place it and level it this weekend. This model looks to have some sort of ball/socket type adjustable mount on the end of the bed where it is mounted to the cabinet.

    It looks to me that this is so you can level/true the lathe bed independent of the cabinet? Looks like you could loosen the ball mount, stick a 2x4 between the bed rails and twist the bed if it needed to be adjusted slightly? If that is the case with this lathe, then maybe the leveling of the cabinet would be less critical?

    What is the process for "leveling" a lathe? What is the measuring method to tell if the lathe is level? Do you put a piece of material in there (at max length), turn it and measure it for consistency?

    Thanks
    Wayne

  • #2
    That's apparently a 3 point mount. If so, you CAN'T "level" it (remove bed twist) but then you shouldn't need to either.

    Sheldon's are rigid enough that it oughtn't to be an issue anyway.
    1601

    Keep eye on ball.
    Hashim Khan

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    • #3
      If you're going to run any coolants, you want the bed to allow proper runoff. If not, don't worry about the base being level too much.

      The simplest way to level the bed is with a precision machinist's level (0.0005" in 8" or so) and some precision blocks and shims to allow the level to sit on the inner and outer flat ways in an area that shows little or no wear (directly under the spindle nose and probably under the tailstock at the right end.

      "Level" is not important but flatness of the bed is. The level is our way of achieving this flatness. It doesn't matter if the bubble is off a bit as long as it is off the same amount and direction at both ends of the bed.

      If you can't get a precision level AND as a final check anyway, chuck a piece of mild steel or aluminum 1-1/2" to 2" diameter and turn two rings about 6" apart. The cross slide should not be moved so it's a good idea to remove some material between those rings and then take a light, final cut with a sharp, small nose radius tool, across the rings.

      With a dial indicator, indicate the two rings to see if you have any taper.

      Slight adjustment of the bed twist can correct the taper, provided there are no other problems. I don't know if the Sheldon headstock sits on Vee ways or not. On some machines the headstock can be adjusted to be parallel with the ways and this introduces another complication to the level adjustment.

      I have to respectfully disagree with JT on the rigidity of the bed. Unless it's a massive Monarch or Hardinge bed with three point mounting, it's a good idea fasten it down well after leveling by whatever means it provides.

      Oh yeah, almost forgot, these suggestions are for use WITHOUT a tailstock center. You can repeat a similar test later WITH a tailstock center and create a test bar that can used at any time to adjust the tailstock offset for no taper or for a desired taper.

      Den
      Last edited by nheng; 04-22-2006, 10:36 AM.

      Comment


      • #4
        Eh, take a look at the picture.....

        That does not look like a very adjustable mounting........ So it may not matter if its wet sphaghetti... it may have no way of being un-twisted. All oter Sheldon's I have ever seen had normal feet.

        Obviously this one is different.
        1601

        Keep eye on ball.
        Hashim Khan

        Comment


        • #5
          JT, I see what you mean in this example which appears to be very similar except it's 11".

          http://www.lathes.co.uk/sheldon/page2.html

          Wayne, If you have problems with operation of the lathe (tapers, chatter, etc.) you might want to clone the original mount, which appears to be cast iron end feet.

          Comment


          • #6
            It looks to me like you could bolt something to the bottom of the bed, just inside the single point mount, and use that to control the tail end of the bed. You might have to lay a piece of flat bar across a couple of webs to get somewhere for the bolts to attach to, and hopefully this wouldn't interfere with the tailstock being able to move along the bed.
            Even if the bed isn't twisted at all, this might still be a good idea just to help keep the flex down. Of course you would be relying on the stand to provide that enhanced rigidity.
            I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

            Comment


            • #7
              Can't tell much from your picture.
              If the tailstock foot is solid, ie: no adjustment, then level the lathe in the conventional manor; get it approx level L to R, then level it front to back as close as possible.
              If there is an adjustment in that foot, ala SBL, then procede as above L to R, then level the headstock end, then tweek the tailstock end to match.
              You may have to bolt the lathe to the floor, using a push-pull system on the floor to achieve level.
              If that foot is a ball and socket, that is not lockable, get rid of it, or at least make it lockable, otherwise it will only cause you trouble.
              Harry

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              • #8
                Thanks guys. I received some more info on the lathe this morning from a gentleman on one of the yahoo groups. It seems the Sheldon's built on this type of stand were intended to be put in service trucks. The mount was intended to be left slightly loose to help with travel vibrations/twisting, and such. They would tighten the mount when the lathe was going to be used. Hard to tell in that photo but the stand under the headstock end is tapered where it meets the ground. This was to fit over the wheel-well in the truck. This may help to explain why there seems to be so little wear on this machine. Maybe it spent most of its life riding around in the truck with very little actual use.

                I've made several test pieces now and cannot detect any variation or taper. I think I better leave it alone else I'll mess it up.

                Wayne

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