Leveling Lathe how important?

I'd leave it there until you decide that's insufficient for some reason.

You can always block the cabinet up so it's not resting on the casters and level that, probably no worse than you'd get with any other wooden bench.

Assuming the cabinet doesn't wobble or vibrate... if it does, that rather than levelling might be your first reason for replacing it.

Atlas isn't exactly known for precision work, but levelling is good practice and can help to prevent the ways from becoming warped.

If you are happy with its performance then its set up right for you. Until you run a lathe that is set up right, you will never know the difference.

John

What will you be using the machine for, what sort of accuracy do you expect of it?

Do you need to turn diameters to within a thousanth, or are you still feeling your way in the hobby?

Do you need to have the parts you make exactly the same diameter at both ends, over a long (say, six or ten inches) length, within a thousanth? Or are you going to be working with shorter parts?

If you want to see what the general condition is, chuck up a piece of one inch diameter aluminum, and turn it down a bit over a six inch length, without moving the cross slide. Use a dead sharp tool and only take a couple of thou off.

Mike the diameter thus formed at both ends, and compare the two readings.

Jim

Jim; This all made me think. I have not needed anything turned in 40+ years so it must be a hobby. I have always been fascinated by lathes since childhood. Just for my own edification I want to test my skills and the quality of the machine - that I would never have paid serious money for - but it was available I have room since I just got rid of a couple of cars. I did have to assist an adult 'shutting of' a lathe as a child as if that means anything. Your test looks like a good one. Perhaps I should do a before and after leveling. My measuring instrumentation is as primitive as can be. Got to check the store . Just plowed through three books on the subject.

Mike

Really all you need for this test is a micrometer. That's it. If you don't have a good one inch micrometer, that really is the first measuring tool you should get, aside from a six inch scale. Starrett or Brown and Sharp are some of the well-known brands, a cursory ebay search will show what they're worth.

You don't need a level to level a lathe. Basically you do the test above, and adjust the twist on the bed so the machine turns and bores true. But the only tool needed is that one inch micrometer.

Sure you could go out and spend hundreds on a precision level, but when you were done you would still need to perform the 'does it turn and bore true' test using your micrometer, and make final adjustments to the machine. So simply cut to the chase and purchase a micrometer which you will need anyway to make or repair parts using your lathe.

Jim

Are you a fan of electronic micrometers? They appear to be far less expensive for performance specs. So far a thickness gage set and a beat up caliper etc. is about all I have.

Mike

For this size and smaller lathes I believe thatprecision levelling is unimportant - the gravitational forces are too small. The really important thing is any bed twisting forces that may be produced by the method of mounting. Four point bolting to an uneven surface is a prime candidate for trouble.

If the overhung loads on the lathe are reasonably small arranging for three point mounting is non critical and avoids mount induced twists.

If, in light duty bench mounted lathes, there is a large overhung load such a the drive motor this may produce significant bed twist. This can be corrected by four point mounting and this is when shims or precise adjustment is needed on the two tailstock end mounts.

This adjustment becomes critical if the lathe is bolted to a very rigid surface - if the surface stiffness is comparable to the bed stiffness even .003" shims are not fine enough. The sheet metal cabinet mounting or plywood surface mounting of lathes are much less stiff than the lathe bed so coarser increments are acceptable.

Jim

"Leveling a lathe" has produced a number of long threads. Basically, the leveling of the lathe bed sets both ends of the bed to the same angle to the spindle. When it is done properly, the lathe will cut a true one diameter surface from one end to the other. If the level is off of one end to the other of the bed, you will have a cone instead of a even diameter rod. Thus the important thing really is to make it so that it will cut that cylindrical surface rather than a tapered one. I'll also note that they use lathes aboard ships and ships are never very level for long yet the lathe will produce as good a shape as one ashore. Mount the lathe solidly to something so that it won't twist, chuck up a nice large diameter rod in the chuck and twist the lathe until you can measure the same reading on a dial indicator mounted on the slide as you move the slide from one end of the lathe to the other and when you do, you'll have the proper alignment of the lathe to do good work.

-- Why do penguins walk so far to get to their nesting grounds?

No, buy a new or lightly used starrett or B&S one inch micrometer, that reads in thousanths.

You could get, but don't really need, the following features in it: reads by tenths, friction thimble, ratchet mechanism, spindle lock.

Basically you're looking to spend about thirty bucks or so.

New will be more, or less if you play the ebay gamble.

Jim

What is your objection to the electronic ones? Reliability or what? Mike

I wasn't in the discussion, but for me it is that if I pick it up after not using it for a year or so, it will work.

I have enough things that I need to feed many styles of batteries already. I like my electronic things but I also like good mechanical things that never will need a battery and work fine for me.

A lathe must be carefully set up to be straight, not bent or bowed or twisted or it won't cut straight. The easiest way to do this is to precisely level it.

People who level their lathe in one spot are missing the picture. You need to level both directions from one end of the lathe to the other and you need a level precise enough to see a thousandth's of an inch over a foot difference at one end relative to the other end. This way you can shim all the twist and bow out of the bed.

If the level is not gradated with .001" per foot or finer increments and if you aren't leveling the entire bed in both directions, you're not getting it.

If you want a good one, you can't pass something like Mitutoyo. But they are expensive. A cheap electronic one is often enough the worsest crap on this planet. Don't relay on nonames when you need accuracy. If you don't want to spend that much money, get a mechanical.

BTW: I bought an inside micrometer (mechanical) some years ago. Didn't use it that much and never trusted it. With it came a reference (gauge) for

5mm. Recently, I took it to my tool dealer for checking it. The gauge was within 0.0005mm accurate. But the spindle has a pitch error of 0.003mm per milimeter. Crap! Useless crap and waisted money!

Nick

Electronic *what*?

Micrometers or calipers?

I'm old school. First you learn to read a micrometer. Which means figuring out the system, and getting practice with it. The micrometer will read down to a half tenth pretty reliably and does not need any fancyness about it. They don't break and they don't need batteries.

Examples:

or

If you want to spend more money you can buy some calipers, for that I do suggest the mitutoyo electronic scale type. Much more immune to fouling from chips or debris than a mechanical rack gear type of dial caliper.

But I would say buy a regular micrometer as *well* if you buy calipers. More rugged, transportable, easier to use for lathe work.

Jim

Good discussion. Just did not know anything on the subject. Ebay shopping is not for me period. Like real reliable online or brick stores. Mike

================== The advise is correct if you are interested in the total, classical machining "craft." However if you intention is to "make stuff" you may consider some alternatives such as mechanical digital mics with tenths thimbles. These will read and be far more accurate than the 'prentice could ever hope for, and you can get an entire set for about the same cost as a "real" micrometer.

see:

that these have both the traditional .025 graduations on the thimble and mechanical digital to help you learn how to read a vernier.

Unka George (George McDuffee)

...and at the end of the fight is a tombstone white with the name of the late deceased, and the epitaph drear: ?A Fool lies here, who tried to hustle the East.?

Rudyard Kipling The Naulahka, ch. 5, heading (1892).

I take it that this Enco link you provided is an example of mechanical digital mics with tenths thimbles.

"traditional .025 graduations on the thimble and mechanical digital" Not sure of the mechanical digital??? Like the old dial indicator? Or is this just a vernier scale - finding best matching lines.

I am, no was familiar with slide rules and chemistry accurate scales etc. for measuring very small quantities. The biggest source of error (and fear) was always being off by a factor of ten . Even experts were known to be WTF off. The electronic 'assists' cured much of that.

Mike

Those were to give you some pictures of what I was talking about, and some comp pricing.

Jim