Adventures In 10f Lathe Leveling

[louosten]

To Level or Not To Level...That Is The Question.

I've read several commentaries about lathe set-up/leveling on this Board and others. Some say that it's not necessary; others don't even bolt their machines to their work tables. Still others mount their machines on rolling dollies so they can move them around. I don't have any personal experience with these various options...according to Atlas literature, the Company directs the owner to carefully level the machine, and bolt it down to a firm, substantial work table/bench, that was obviously not intended to be rolled around the shop.

Everyone has their preferences; this is not a treatise on criticism...more like what I decided to do. After reading, you're welcome to comment on the aforementioned alternatives.

I started by purchasing a used workbench on my local Craigslist that would easily support the weight of the machine; my choice was a Craftsman bench with a galvanized top, rated at 1450 lbs.


Then I carefully measured and moved the assembled machine around until I arrived at a location that would accommodate its shape. The hold-down bolt hole locations had to be situated to be accessible.

Following the general Atlas guidelines, I made a bunch of shims from aluminum gutter flashing (.010-.012); after cutting the shapes into roughly 5/8" x 1 1/2", they were stacked into a wooden form and drilled to accept the hold-down bolts:



After drilling, I ended up with this:



Using the shims on top of some 1/4" steel bearing plates, the assembly looks like this:





The mounting bolts go through the shims & plates, and are backed up with rubber isolators (fender gaskets & washers) to reduce vibration:



With the workbench starting out reasonably level, I foolishly thought that the 4 hold-down bolts would take the same number of shims...wrong!




I was using my trusty old machinist's level, obtained from a flea market, and calibrated on a super flat machinist's table years ago...

As you can see, it took more shims on the front left bolt, than any of the others:



By adding shims and checking with the level, the machine was eventually brought under careful control:



The final check was made at an angle across the ways:



Only time will tell, but the procedure has produced a level machine, that so far runs smoothly with little vibration. It was somewhat of a pain to go thru this operation, but fortunately it is only required once (for permanent installations).

Let the comments begin!

Lou O.

 

[eeler1]

Nice write up and flea market find!

Most people focus on front to back leveling, at the headstock end and then the tail stock end. Be ready to iterate over and over again. Making adjustable mounting screws can make it a bit easier and faster. Shims can be a pain.

But the proof is in the cut, does it cut a taper? That's the last part to fine tune your setup. If it cuts a taper, you're not quite done yet, unless you're cool with tapers.

 

[John Hasler]

I make U-shaped shims so that I only need to loosen the bolt to slide one in or out.

BTW levels are self-calibrating.

 

[mmprestine]

Its not the essence of actually leveling the machine but actually using the level to verify that all parts of the machine are in the same relative axis/plane with zero offset/twist. Some people prefer a small actual level pitch to control fluids or direct them to returns.

 

[wa5cab]

Those are good points. If you have a drip pan under the lathe it is better to have a slight drop in the pan from left to right and from front to back (assuming that the drip pan's drain is in the right rear corner). Then level the lathe front to back and left to right as accurately as you can. And U-shaped shims make doing the leveling job infinitely more pleasant. You can buy shim packs from places like McMaster is several different sizes and materials. Having done it both ways, I can confirm that using accurate machine-made shims is much more fun than using home-made ones.

Also, if you must have your lathe on casters, you will just have to tolerate some poorer performance. If the operating spot is always the same, you can minimize the degradation by carefully marking the exact wheel or leg spots on the floor and always returning the four casters or legs to the same exact spots.

Finally, once done, always done isn't always true. Leveling should be re-checked at least annually because of the probability of shifting or subsidence in most parts of the country.