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  • New member with possibly dumb question about building a lathe base.

    I am an old, but still rank amateur "machinist," have had a Craftsman/Atlas lathe and a Taiwan vertical mill in the past. I recently bought an older Enco 12X36B lathe, no gap. By the look of it, it had been used very little, though it is very dirty. I know enough about Chinese tools to consider them conditionally-acceptable for my sort of light-duty, hobby-level use, the condition being that you regard them as pre-assembled kits that the buyer should completely disassemble, clean, de-burr, chamfer, replace rough-feeling bearings, and then assemble, mount and level, and adjust. I have this chore ahead of me for my new-old lathe.

    My question is about building a base for it. Previous owner had it on a heavy homemade wooden base. The guy was trying, but I doubt he did any leveling, and even if he did, the wooden base has surely settled since then, and will continue to move. I'm going to weld up a heavy steel base (incorporating cabinet space underneath). I know that any welding I do locks stresses into the finished assembly; time and vibration will tend to unlock some of those stresses and cause things to move around a little. I don't especially want to spend the money to have my finished lathe-base stress-relieved, nor machined. As stated, this base is going to have some real mass to it, and enough bracing to keep it rigid . . . but maybe not on the scale of accuracy needed for a lathe. I suppose I could peen each weld, though there will be lots of welds, and possibly it would help to "ring" the finished base by whacking at it for a while with a heavy hammer (Yes? No?). But maybe this is getting carried away. No doubt some of you have welded up your own machine bases. How much do they move around, in service? With the base lagged to the shop floor, I'll check the mounting pads for level and add shims as needed before mounting the lathe. Should I expect to have to re-level the lathe very often after that?

    Also, I understand that a cast iron base is more desireable for reasons of dimensional stability and vibration damping. But I have to go with welded steel. Has anyone found that putting some sort of vibration absorbing material between the steel base and the lathe, say pads of Delrin, has value?

    I suppose I should have waited for an old American machine to come up, but the price seemed okay, so it got this Enco while I could, and think it will do for my needs.

  • #2
    Hi Smitty,

    You mention 'level' a couple of times. Lathes don't particularly need to be level to function properly - lots of ships have lathes in their machine shops, these work just fine!

    What's more important is that the surface that you bolt your lathe to is flat, and doesn't impose any stresses on the bed. For home shop use, I'd not expect any real noticeable variations in accuracy due to a welded frame moving. However, if you are after mass (which always seems good to me), then how about casting a concrete slab and grouting & bolting to that? The slab can be raised up on a welded steel frame.

    Good luck,

    Ian
    All of the gear, no idea...

    Comment


    • #3
      What about looking for a cabinet/chip pan from a similar sized South Bend / Logan / Hardinge? By the time you buy the steel, you might find a suitable base for the same money.

      Comment


      • #4
        I read an account where the Atlas lathes being mass-produced for their WWII duty were recommended by Atlas to be mounted on a concrete slab - this was done to handle the stress to the bed of almost continuous machining.
        As Ian B mentions, it's more important to be flat and stable for lighter-duty lathes - my 12x30 Atlas is mounted on a 1 1/2" thick plywood table-top covered in Formica, screwed to the wall - it has never had problems of the bed warping.
        Richard in Los Angeles

        Ric

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        • #5
          I wish people would put a general location. you could be across the street around the corner or across the country from me . if the first 2 I would be more then will to help you out.

          I had a 12" atlas that I mounted to a bed made from 8x18 h beam milled the top flat put legs on it bolted on the lathe. I have a 9" south bend mounted on a stand made out of tubing now.

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          • #6
            Since you will be building the base, there is a good chance that you won't wind up with a dead flat surface. I'd say the build the base and shim it's feet until the top is pretty level. Then set the lathe on and shim it for cross level. It probably won't need any attention for a long time, but you should still check it periodically.

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            • #7
              Originally posted by bob308 View Post
              I wish people would put a general location. you could be across the street around the corner or across the country from me . if the first 2 I would be more then will to help you out.
              And you are !
              I have tools I don't know how to use!!

              Comment


              • #8
                Funny-you don't list your location!

                Originally posted by bob308 View Post
                I wish people would put a general location. you could be across the street around the corner or across the country from me . if the first 2 I would be more then will to help you out.

                I had a 12" atlas that I mounted to a bed made from 8x18 h beam milled the top flat put legs on it bolted on the lathe. I have a 9" south bend mounted on a stand made out of tubing now.

                Comment


                • #9
                  All true-but one of the easiest ways to make a surface flat is to make it level.

                  Originally posted by Ian B View Post
                  Hi Smitty,

                  You mention 'level' a couple of times. Lathes don't particularly need to be level to function properly - lots of ships have lathes in their machine shops, these work just fine!

                  What's more important is that the surface that you bolt your lathe to is flat, and doesn't impose any stresses on the bed. For home shop use, I'd not expect any real noticeable variations in accuracy due to a welded frame moving. However, if you are after mass (which always seems good to me), then how about casting a concrete slab and grouting & bolting to that? The slab can be raised up on a welded steel frame.

                  Good luck,

                  Ian

                  Comment


                  • #10




                    this is an epoxy concrete table on hockey pucks. its heavier than the lathe. just great, it dampens exteremly well and is rigid enough to straighten the bed.

                    probably easier, than welding something up and less expensive too. the top layer of epoxy will be lelf leveling.

                    (i know, i posted this before.)

                    Comment


                    • #11
                      Originally posted by bob308 View Post
                      I wish people would put a general location. you could be across the street around the corner or across the country from me . if the first 2 I would be more then will to help you out.
                      I agree .. but .. the suggestion seems more valid when you, yourself are willing to put your location in your account info.
                      John Titor, when are you.

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                      • #12
                        Originally posted by andywander View Post
                        funny-you don't list your location!
                        burn!

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                        • #13
                          In Bob308's defense - HE wasn't the one asking for help.
                          "Patriotism is the last refuge of a scoundrel"

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                          • #14
                            Originally posted by dian View Post
                            this is an epoxy concrete table on hockey pucks. its heavier than the lathe. just great, it dampens exteremly well and is rigid enough to straighten the bed.

                            probably easier, than welding something up and less expensive too. the top layer of epoxy will be lelf leveling.

                            (i know, i posted this before.)

                            That's beautiful - shop-made or commercially made? What goes into the mix of "epoxy concrete"?

                            Comment


                            • #15
                              Build it any way you want. With the possible exception of the type shown above by dian, you'll need to periodically re-level your lathe anyway. (most people here already know that 'level' doesn't mean level in the common sense. Its just the terminology/process we use to flatten the bed)
                              Southwest Utah

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