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1000# Lathe to bolt or not to bolt ?

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  • 1000# Lathe to bolt or not to bolt ?

    I read a bunch of posts on a bunch of sites. I wanted to get some opinions from some of the folks on here.
    I have a SB H10L and a Taiwan 80s copy of the SB. I know from reading the SB comes in at about 1000#s.
    So I assume the copy is close as well. I have them both in my garage on a concrete floor.
    I am not sure how well/deep my concrete floor is but it is poured on top of rock and is 30 years old. So I am assuming it is pretty stable.

    Both lathes have the heavy stand (300#) that has flat feet coming out the side for bolts. So i don't need to support the whole cabinet on the concrete as far as I know, just the feet.

    I am not trying to start a debate. I just wanted some info on what you folks are doing ? Since some of you seem to know a lot about machining. :-)

    I don't plan on selling my house or moving them around so I am leaning towards bolting them down to get the best accuracy I can from both of them. So bolt them down or just put them on some good machine mount feet (which they are currently) and call it a day ?

  • #2
    I would drill a test hole first, you will need at least 4" of concrete. Bolting will eliminate any danger of tipping a lathe over, but it would be difficult to be sure that it would be advantageous for improved accuracy. The Smart & Brown model A at the museum was not bolted down, and I got Rod to lift it up with the fork lift and we put 4" of wood underneath it to save my old back. The lathe sits perfectly well on the wood, and we have not noticed any change in its accuracy. It has a substantial cast iron stand and weighs over 1400 pounds.

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    • #3
      IMO, your choice.

      Nothing makes the arrangement you want change faster than bolts into concrete. I do not have anything bolted down. The one thing about lathes is that they are really top-heavy, and either bolting, or attaching to wider "feet" somehow might make a lot of sense. If you were in LA or other earthquake areas, I bet you would not even be asking.......

      One other thing about bolting, is that you may be able to shim the stand, so as to help get and keep alignment and "level".
      2730

      Keep eye on ball.
      Hashim Khan


      It's just a box of rain, I don't know who put it there.

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      • #4
        Only in earthquake territory or on a ship, other than that I see no reason.

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        • #5
          If your machine is already on proper machinery mounts then I would start with that. If in time your lathe is moving and changing it's cut then you may have to fasten it down to make it hold tolerance. Now if earthquakes are your concern then you can run bolts through the holes into the floor but not cinch them down. Let the lathe stand free but the bolts will hold it back if it starts to walk.

          lg
          no neat sig line
          near Salem OR

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          • #6
            When you have a top heavy machine and want to secure it in earthquake country, you do not want it to be loosely bolted. A quake that is strong enough to topple a 1000# pound machine will cause it to act like a slide hammer on loosely secured bindings. I used to know a lot about earth quake bracing, but the last time I needed to do it right was 25 years ago and I've forgotten a lot in 25 years.
            At the end of the project, there is a profound difference between spare parts and left over parts.

            Location: SF East Bay.

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            • #7
              Originally posted by danlb View Post
              When you have a top heavy machine and want to secure it in earthquake country, you do not want it to be loosely bolted. A quake that is strong enough to topple a 1000# pound machine will cause it to act like a slide hammer on loosely secured bindings. ......
              This is very true. But I suppose "loose" doe not have to be a half inch of free motion, it can mean just not quite snugged, so that there might be only 0.020" of movement, or less. That would cut the "slide hammer" potential.

              But, if you have a 4" floor of more, it seems that actually bolting down might be practical. it used to be machines were bolted even to wood floors, so concrete would be better. If the floor here were not so thin, I'd bolt at least the lathe down. But the floor here probably would not hold down against the forces of an earthquake.
              2730

              Keep eye on ball.
              Hashim Khan


              It's just a box of rain, I don't know who put it there.

              Comment


              • #8
                1000 lbs for a lathe is not that heavy. Also depending on what it is sitting on it may not be sitting on the pads of the bases evenly. And if that is the case the bed may be flexed out of true or will flex during some particularly heavy cuts. or for that matter if sitting loose and relying on only gravity when doing a long part with the center in the tail stock set into the part firmly it will cause the bed to arch up slightly. It's only a thou or two but depending on what you're doing it might make a difference. And if bolted down and secured solidly and well bedded you have a good platform to use for shimming or otherwise tuning the lathe bed to where it is true.

                So all in all I'd bed the bases so they are not sitting with uneven contact on some odd lumps or uneven floor. And bolt them down and from there true up the bed for the best results. Resistant to earthquakes is really just a bonus to all this.
                Chilliwack BC, Canada

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                • #9
                  1000# Lathe to bolt or not to bolt ?

                  Semantics {logical form}. This joint is full of them.

                  1994? The bed was doing a jig like right out of Alice In WL. It was a bad quake. Refrigerator popped out on the sink. Walls were crispy, dry wall joints broken.

                  I was happy to live in the end of the street where we all gathered. The quakes don't stop at ones.

                  Community. Just so happened my neighbor and freind was a welder.

                  Big ol blue box in his truck running all night....

                  I have had other shakers after that and none of my machines wanted to fall down. Thank God for that.

                  I do like garage floor inserts. I have a few.

                  You should see the one for the 2x2 tube 18" done for my harbor freight electric winch. For my car body to work on in the driveway then tow up into the garage.

                  JR
                  Last edited by JRouche; 10-11-2019, 01:42 AM.
                  My old yahoo group. Bridgeport Mill Group

                  https://groups.yahoo.com/neo/groups/...port_mill/info

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                  • #10
                    OK, I think I will drill a test whole in the concrete just for fun.
                    I am outside of Philadelphia, PA so I am not worried about earthquakes.

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                    • #11
                      I have set a lot of machines up never bolted any down. as others have said bolting them down can lead to other problems. the only reason to bolt a lathe or mill down would be on a ship. or a mobile machine shop.

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                      • #12
                        generic advice: if it easier to do it than to explain why you did not do it, just do it.

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                        • #13
                          My import 12x24 is in the same neighborhood weight wise, likely more like 800lbs with the stands. Having just lifted it the other day with an engine hoist I was reminded how top heavy and unstable this thing is. Not much of a nudge would topple it over, and it vibrates/chatters pretty easily. Oh, it's also twisted slightly and not heavy enough to correct that under its own weight. Because of this I've always wanted it bolted down but the stand design doesn't allow that without modification, and I kind of want to ditch those stands anyway. It's on the to do list.

                          In my mind the vast majority of 1000lb lathes would benefit greatly from being bolted down.

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                          • #14
                            In some ways, the lighter the lathe, the MORE benefit it would have from bolting down.

                            Heavy ones may settle better, and can be adjusted partly with the foot screws. Light ones do not, and need a solid surface or stand to which they can be bolted to be forced into alignment.

                            Originally posted by AD5MB View Post
                            generic advice: if it easier to do it than to explain why you did not do it, just do it.
                            I like this......
                            2730

                            Keep eye on ball.
                            Hashim Khan


                            It's just a box of rain, I don't know who put it there.

                            Comment


                            • #15
                              Keep in mind too that bolting it to the floor will only be a benefit to better machine setup and performance IF the bases are bolted to a truly flat and planar floor. Few slabs of concrete are actually that flat. Which is why I suggest some manner of bedding between the floor and the stands if they just sit on the floor. Or shim where the pads are located until they are all sitting equally with no tendency to rock corner to corner.

                              Going back a few years now I posted about tossing the tin boxes that came with my own Asian 12x36 in favor of building stands from construction blocks and mortar then filling them and setting studs in the top in concrete for the actual lathe. Some considered this overkill at the time. And perhaps it was. But it was cheap to do and relatively easy. What I didn't expect was how it improved the performance of my lathe beyond anything I would have hoped for. First off when I went to true up the bed having a solid base like this made it easy to make minor changes that actually did make a change that could be seen easily. So I was able to straighten the bed in twist and arching to where my parallelism was measurable as being within a third of a thou over 7 inches (the length of the test bar). I'd have been happy with anything around a thou or so. But having the truly solid and rigid pedestals combined with the jacking and hold down nuts allowing me to dial in changes it was super easy and quick to achieve really fine adjustments. Also cuts that I had made in the past with the unmounted "cookie tin" box pedestals that chattered like magpies easily were now smooth as warm butter. Parting and heavy hogging cuts don't cause any issues now even done at higher than backgear speeds.

                              So there's many advantages to correctly bolting the lathe to the floor. But it needs to be done with proper planning and measuring if the goal is to improve how well the machine performs.

                              And yes, I know how much of this is repeating what I posted earlier. But the improvement that is possible for any smaller "bench lathe" with at least using the present stands wisely is worth a bit of harping on about this idea.
                              Last edited by BCRider; 10-11-2019, 01:04 PM.
                              Chilliwack BC, Canada

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