Leveling a Lathe

Hi there,

In thinking about picking up my SABEL lathe next weekend, I have been reading about installing it and the issue of levelling is often mentioned with the use of an (expensive) engineer's level.

My question is, how important is it to use an engineer's level when setting up the lathe? Would not a normal level be sufficient?

regards

Brian

Hi Brian,

have you searched for Lathe Levelling on this forum?

Regards

Thor

Not very hi tech but I levelled my lathe with a bit of 2" silver steel. Put it on the bed at various points, squarely across, and adjusted the height adjustment to stop it moving. I then put it about 45degrees to the bed and again adjusted for front to back linearity until it stopped to move. I did this about 30 years ago and it still seems to be OK. I have checked it with a proper engineer's alignment level but I gave up when I ran out of time.

I have now Thor, thanks,

regards

Brian

Brian

If you had a precision level then it is a good way of testing that the bed is not twisted, which is the important thing. A slope of say one degree at each end would still indicate that the bed was not twisted but that is difficult to test.

However, even if the lathe is set up using a precision level a test piece would still have to be turned to make the final adjustments. As you do not have a precision level there is no need to go to the expense of purchasing one.

First set up the lathe using a DIY level and then go down the test piece route to finally set the lathe to turn parallel.

If you are not conversant with the method of turning a test piece I have attempted to cover the subject in detail on my web site which you could view. The details are available at **LINK**

It is worth bearing in mind that no lathe is perfect, even a precision one. You may therefore end up placing a very minute twist in the bed to compensate for errors in its manufacture, Hence the reason for turning a test piece even if set up with a precision level

Harold

Some years ago I was shown round a diving support vessel while docked at Grimsby.

Down in the bowels of the ship was a Colchester sized lathe bolted down to the steel plates of the workshop floor. The ship had suphisticated multi thrusters to keep it on staton over work areas, but a level machine? Not possible out at sea and it would still be needed to fix or mend things in a hurry..

British nuclear submarines used to have [and may still do] a Myford 7 lathe securely bolted to heavy thick steel plate in the turbine section , again liable to all sorts of angulation from level.

I think the real secret is more to do with mounting up on a really solid surface to resist distortion or flexing, after all if that is the case then everything is, and should stay, in register.

Brian

As Brian notes, the important thing is the lathe/mill whatever has all its bits either 'Plane' or 'perpendicular' as the case may be. Nothing 'magic' about 'level'.

One easy practical way of measuring how well this has been achieved is by using a reference surface. A spirit level uses 'earth' (via gravity) as a reference. The 'plane' surface is therefore 'horizontal', and perpendicular surfaces determined to be 'vertical' by use of a set square.

-russ

Sugest to search this forum for leveling as it has been discussed many times over the years.

Enjoy your new lathe and good luck

Bob

Bother, I'v got Chapman 1 and 3, and the secondhand bookshop that sells those sort of books in Christchurch is no more, lost the origional shop in the first earthquake, they moved a block down the street to another shop, they lost that onejust comming 2 yrs ago in 2 days time. Oops just been away and had a look, they are back in business at Smiths Bookshop Tannery Emporium 3 Garlands Rd Woolston, Christchurch, just in case any Christchurch people are interested, smithsbookshop.co.nz sell on line, I'v got heaps of old books, and Model Engineer mags from them in the past, including Chapman 3.      Ian S C

Edited By Ian S C on 19/02/2013 12:48:24

Can anyone point me at the Schlesinger Tables on line? I have tried google - I'm sure they are out there, but lost in a sea of general information about Schlesinger and claims that various equipment is made to them.

Neil

Hello Graham,

Many years ago Tubal Cain had an article in ME on the alignment standards applicable to Myford lathes, I clearly remember him referring to Schlesinger standards in the article and quoting from them.

The ME in question would have been after 1988 and of course before he died [1996?] I recall taking some interest in attempting to apply them to my Dad's old ML4 which I had at the time, having the time available to grapple with it.

The title would have been something like 'Aligning a Myford lathe', but I can't be more definite.

Brian

I've just looked at my copy of the article in question.

It's from the ME 5 October 1973.

If anybody would like a copy of the two page article PM me and I will scan in my copy and e-mail it to whoever.

My copy says "continued from page 916" but it looks like all that one needs.

Len. P.

I've just read the article again.

It's not Myford specific but covers general setting up of lathes. No doubt the later article of 1988+ would be more appropriate.

Len P.

There are 13 pages in the original article 4Oct - 31 Dec1996. Schelsinger tables on one of these pages, page 397

Alibris World of Books have two copies of Chapman Vol 2

.

Nearly ... but it doesn't seem to include the actual charts !

MichaelG.

Quotes for Schlesinger standards from a book owner. Source Mad Modder

"For Finish Turning Lathes": "Lathe faces (hollow or concave only) within 0 to 0.02 per 300mm in dia."

"For Toolroom Lathes (Highest Degree of Accuracy)": "Lathe faces (concave only) within 0 to 0.015 per 300mm in dia."

"For Facing Lathes": "Lathe faces (concave; only for machines with headstock and carriage mounted on common baseplate) within 0 to 0.05 per 1,000mm in diam."

So, all of these are much better than 0.001" per 3" in diameter and, in all cases, they can be zero.

Brian

Thanks to everyone who has replied. I can see that the main criteria is obviously twist, or should I say the avoidance of it.

I will have to see how I get on when I get the lathe this weekend. Probably won't get it all set up for a week or two as it needs a good clean as I re-assemble it.

regards

Brian

You have Brian come to the correct conclusion regarding setting up the lathe, Twist is much more important than level.

In the tolerances you quote you state that "all can be zero" and you are theoretically correct, However, no manufacturer would aim for that value as a very small deviation in the wrong direction could at best result in parts having to be reworked, or at worst scrapped.

They will almost certainly aim for somewhere in the middle of the tolerance range as a result a small deviation from perfection is almost inevitable.

Harold

Hello Harold, Graham and others interested,

I have dug out my copies of Tubal Cain's article in ME on levelling a lathe. As KWIL pointed out, page 397 shows the Schlesinger limits for lathes of various quality standards along with the factory test report for his Lorch precision lathe. I also have a Holbrook factory test report from 1984 [found on Mad Modder]

Cain's article deserves reading, it is relevant, interesting and of course well written as you would expect.

I'm not sure about copyright issues in reproducing the page in open forum but it can be made available for those interested via a PM

Brian