Importance Of A Twist-free Lathe Bed: Leveling

wildo

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I can't possibly be more excited to be picking up my South Bend 9A tomorrow! Do you guys remember your first major machine tool? Man... so unbelievably excited!!

So I've been doing a ton of research on leveling the bed. I picked up an 8" Starrett machinist level and think I have all my bases covered on setting up the machine. One thing I've been considering is how difficult it is to deal with a wood base moving throughout the changes of season. Since I don't yet have the experience of dialing out the bed twist, I can't really know how picky it is and/or time consuming.

To get to the point- I've considered purchasing some adjustable leveling feet for the lathe. My question is- are these worth it? Certainly it would be much easier to adjust a cap screw than to have to unbolt the lathe and and/remove shims. But... maybe this is a trivial matter? My lathe will be indoors in a reasonably climate controlled environment. (Probably low 60's in the winter and mid/upper 70's in the summer.) The bench is 2" steel square stock and the bench top is 1.75" thick butcher block maple.

So would you suggest the leveling feet, or would you stick with simple shims?

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Either will work, your choice. If the stand is too stiff you may need to shim it anyway to produce some results. The lathe will settle for some time after setting it up. It will move and flex as it settles in. Level it, repeat in a few days or a week, again in a month or so, and then occasionally. The floor will also move with time, even if it is concrete, from the added weight. That said, there are also reasons for not making the lathe completely level. Worn ways often require twisting the bed to take out the taper produced by the wear. Wait until it settles a while to test for that, and for other needed accuracy adjustments. There are lots of guides on how to set up your lathe and make it produce it's best possible work. Some are probably on this site. Read several of them and make sure you understand them, and then choose the method that looks like it will work best for you.

Congratulations on the 9A!
 
Thanks for the comment Bob! I guess my question though is if it's actually worth investing in the adjustable feet. I know both methods will work just fine. And I gathered that there will be some movement there. But I don't have the experience to know if the convenience of being able to turn a simple screw is worth the monetary investment compared to the much cheaper shim stock. At $83 shipped, maybe it's a moot point. But as a newbie who apparently wants the world, I'm finding the startup capital needed to get tooled up for basic work a little overwhelming. That $83 could buy me a "cheap" indicator. Or a Noga base. Or a set of parallels. Or...
 
Use your new lathe to make yourself some feet for your lathe, if you want. Another issue is the height of the stand. You may want to adjust the height for comfortable working. It might be better without the feet. Or it might need to be higher. Bent over is no fun, and it is nice if the controls come easily to hand. I bought some feet for my mill from Grainger. They have lots of choices and some of them are quite reasonably priced. Take a look there. I recommend you set the lathe up and play with it a bit before you make any final decisions.
 
When I bolt down a tool I usually use washers as shims where I can. Sometimes I'll turn one down a little thinner or use shim stock if it's critical. Once in a while I need to make adjustments regularly so I'll use a nut above and below the casting, much like the way your machinists level is adjusted to it's base. In the case of my Sheldon I found not twist in the bed but a down bow about 3/4 down the ways at the tail end. I needed a shim under the far right end of the right foot and quite a bit of down force on the right side mounts. But it worked. I found the greatest nuisance was finding a good surface to reference the level. Seems there's a little bump or ding everywhere I sat the dang thing. I decided to mount the level in place of the compound and that gave me the best repeatability. Measurements aren't useful if they aren't repeatable.
 
All lathes will move and require periodic leveling. This can take minutes to days, depending on your luck. The easier it is to do the happier you will be, trust me. $83.00 for the convenience of avoiding shims is a small price to pay in my opinion and I would definitely go with them. You can lift the lathe, add a shim, bolt it down, lift it, shim again, etc or you can turn a screw ...
 
I found the greatest nuisance was finding a good surface to reference the level. Seems there's a little bump or ding everywhere I sat the dang thing. I decided to mount the level in place of the compound and that gave me the best repeatability. Measurements aren't useful if they aren't repeatable.

I bought a grizzly 18" x 24" x 3" granite surface plate for that task. (And obviously other tasks.)
 
All lathes will move and require periodic leveling. This can take minutes to days, depending on your luck. The easier it is to do the happier you will be, trust me. $83.00 for the convenience of avoiding shims is a small price to pay in my opinion and I would definitely go with them. You can lift the lathe, add a shim, bolt it down, lift it, shim again, etc or you can turn a screw ...

Maybe I just wanted to hear someone say it. This seems logical to me. Turning a screw seems SO much easier... I just wanted to make sure I wasn't missing something!
 
My old Logan 1957 has adjustment bolts, not quite as convenient as the southbend setup, but beats heck out of shims as far as convenience. Easy to check level every couple of months and adjust.

Bob, I'll have to ask you about level vs twist tests. I just try to make it cut straight regardless of twist or level.
 
Maybe I just wanted to hear someone say it. This seems logical to me. Turning a screw seems SO much easier... I just wanted to make sure I wasn't missing something!

The first time you have to chase a bubble you will be sooo glad you went for the adjustable feet. Even with them, I have spent hours getting to level. Some days, it takes minutes. God has a great sense of humor!
 
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