# Getting the twist out of a Clausing 4900 lathe bed



## shocktower (Sep 15, 2014)

Ok I am at wits end, trying to get my lathe close to level, I bought a Starrett # 98, have good feet solid concrete floor, and yet I cannot get my lathe close to being level across the bed. How can I get the twist out ????? :whiteflag:


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## Terrywerm (Sep 15, 2014)

Let me guess:  You leveled the headstock end first. Now, if you adjust the feet at the tailstock end to remove the twist, you end up with one foot in the air, but still have twist in the bed, correct??

It is possible that your lathe sat somewhere for a long time with the twist being induced into the bed. You may have to allow some time for the twist to come out. You could also try adding some weight to the foot that is hanging in the air. You might even find that this becomes a time consuming process, leveling and weighting the lathe and letting it sit for a few days, then come back to it and try again. You should eventually get the twist out of it.  Once you do, then level both ends front to back, then raise or lower the tailstock end to bring the machine to level down the length of the bed.  One other thing to remember is that front to back leveling is much more important than having it level down the length of the bed.


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## shocktower (Sep 16, 2014)

terrywerm said:


> Let me guess:  You leveled the headstock end first. Now, if you adjust the feet at the tailstock end to remove the twist, you end up with one foot in the air, but still have twist in the bed, correct??
> 
> It is possible that your lathe sat somewhere for a long time with the twist being induced into the bed. You may have to allow some time for the twist to come out. You could also try adding some weight to the foot that is hanging in the air. You might even find that this becomes a time consuming process, leveling and weighting the lathe and letting it sit for a few days, then come back to it and try again. You should eventually get the twist out of it.  Once you do, then level both ends front to back, then raise or lower the tailstock end to bring the machine to level down the length of the bed.  One other thing to remember is that front to back leveling is much more important than having it level down the length of the bed.



That is exactly the problem I am having, I did the weight thing, but didn't wait long enough, I guess I'll have to be patient, I will give it a shot tomorrow and let it sit for a couple of days, it has been frustrating to me I will give it a go . thank you for your time.


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## Terrywerm (Sep 20, 2014)

I suspect that your lathe may have sat in one spot for a long time, but in such a way that a twist was introduced into the bed. If that is the case, you might have to add quite a bit of weight to it, and may have to leave it for some time to get it to straighten out. Be prepared, it may take weeks or months, not just days.

One thing that may help would be to increase the applied force to the bed. First, set the lathe so that the 'high' foot is off of the floor, but only by a slight amount. Next clamp a three foot long piece of 2" square tubing or something similar to the tailstock end of the bed. Clamp it on in such a way that it can apply a twisting force to the bed in the correct direction when a heavy weight is hung on it. Apply some weight (hundred pounds or so) and then check to see if the high foot is still in the air. Leave it for a few days. 

Repeat the process as necessary until the bed comes into a position where it remains fairly straight on its own. 

I must caution you against applying too much force, and do not be tempted to raise the end of the lathe higher to allow more 'reverse' twist before the high foot touches down. You don't want to overdo it!  Just remember that patience will be key on this project. You want to tweak it back just a tiny bit at a time.


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## John Hasler (Sep 20, 2014)

shocktower said:


> That is exactly the problem I am having, I did the weight thing, but didn't wait long enough, I guess I'll have to be patient, I will give it a shot tomorrow and let it sit for a couple of days, it has been frustrating to me I will give it a go . thank you for your time.



Just bolt it down with adjusting screws and adjust the screw on the leg that is now in the air until you get the twist out.  You really only need bolts on the leg that needs to be pulled down and the one diagonally opposite it.


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## george wilson (Sep 20, 2014)

I don't know about your lathe,but my 16" Grizzly Taiwan made lathe sits on a heavy,welded,thick steel base. I found it necessary after trying to get the whole lathe and stand leveled,to loosen the front rear leg of the lathe bed. I put shim stock under the foot,and tightened it down,to remove a small amount of twist in the bed. After that,I was able to properly level the lathe through the feet that sit on the floor.

If you have a very heavy,rigid cabinet like this,you may be able to do the same thing.

It is more likely you have a thinner sheet metal cabinet. In that case,you must drill holes in the concrete floor. Use stout fasteners to pull the lathe down,and shim the foot that needs it with shim stock till you get it level with itself. It doesn't need to be completely level,just level with itself as far as twist is concerned. Lathes on ships are never level,they just are setup to eliminate any twist in their beds. They cannot use levels on ships. The lathe is setup using accurate test bars,or by cutting long test pieces of steel,until the pieces are the same diameter along its length. Before they do that,it must be ascertained that the tailstock is perfectly aligned with the spindle.


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## John Hasler (Sep 20, 2014)

Actually, it doesn't need to be level at all.  The ways need to be flat.  Leveling is just one means to that end.


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## awander (Sep 20, 2014)

John Hasler said:


> Actually, it doesn't need to be level at all.  The ways need to be flat.  Leveling is just one means to that end.



But, a very easy means to that end.

Having the lathe level can also assist in certain setups.


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## John Hasler (Sep 20, 2014)

awander said:


> But, a very easy means to that end.
> 
> Only if you have a precision level.  I can't justify $200 for a tool I will use twice a decade.
> 
> Having the lathe level can also assist in certain setups.



If you have a precision level.


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## awander (Sep 20, 2014)

You can pick up a good used level for much less than that. I got my precision level(Chinese) from Enco for about $59 on sale. It is sensitive to 0.0005"/ft.


A Starrett 98 with sensitivity of 0.005"/ft, which is what many use to level their lathes, can be found used for as low as $25.

(Of course, I always use any excuse to buy another tool)


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## george wilson (Sep 20, 2014)

You can do it without a level. I didn't have one for some time after I got my first lathe. Put a new,sharp dead center in the spindle and in the tailstock. Bring the tailstock up to the spindle and sight straight down on them. Adjust the tailstock until it's center is exactly centered on the spindle's center under magnification. Make sure it is also the same height as the spindle's center.

Then,slide the tailstock back and put in a long bar of steel that is held between centers,or even in a 3 jaw chuck,and a drilled center hole on the tail stock end. Take a cut the length of the bar,then take a very light cut. Measure both ends of the bar. If the bar is smaller at the tailstock end,shim the front leg of the lathe a little. Shim the rear foot if the bar is larger at the tailstock end. Take another cut,then a light cut. Measure and add shims as needed until the bar is the same diameter at both ends.

Some make a test bar by turning the bar down,leaving a larger diameter place at each end. That saves time in making a long cut. Just turn the 2 larger dia. ends and check their diameters.

If your lathe has worn ways,it presents a whole different set of problems. You may not be able to get the bar turned evenly because of worn ways. In that case,I would resort to a precision level sitting on parallels to check each end for levelness. In any event,make sure the tailstock is perfectly aligned with the spindle as described. If you do not,you may be twisting your lathe trying to get it to cut a parallel bar.


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