How to Level a Lathe

[John3]

I just got my 1979 Wasino Samurai-5 (model LENUC-5N) Gap Bed CNC Lathe up and running. Its a beefy 22x40 inch machine.

There are four leveling pads on each end of the machine. Four in an approximate 24" square pattern for the head stock and the same two foot square pattern of four leveling bolts for the tailstock end.

Right now, it's sitting high on the four outside pads. My question is what would be the best procedure for distributing the load on all feet. Obviously I know how to make the machine level, but I'm not sure what I should do about distributing the load on the eight pads. How this gets done probably affects the accuracy of the machine.

Anyone out there who has leveled a similar machine with the help of a manual.

Thanks in Advance for any comments!

John

[ben_heinman]

Simply all you do is get the machine level with the 4 outer pads and then snug up the other 4. Just make sure to check the level after you have done this. The most important part really is to make sure it is cutting parallel. All you need to do is grab a scrap piece (3" dia. recommended) and run a cut of the diameter about 4"-6" long. Measure along the new diameter, if you are within .0005" you are doing good. If it is out by alot then you will have to square the head and that will be a whole different procedure. It doesn't really matter how level the machine is, it's more about the squareness of the cut.

[John3]

Ben,

My concern is / was that if I don't properly distribute the load front-to-back and side-to-side I could put twist or bow in the ways affecting accuracy and wear. 'Sounds like you're saying don't worry about that?

John

[Geof]

I have not levelled a lathe like you describe but have levelled a mill with six pads.

The manual was not much help because it just said level the machine with the same load on each levelleing screw. Which was more or less impossible because the weight was not distributed evenly among the six points so they could not all carry the same load.

I levelled the entire machine from the four corners trying to make sure the two front screws seemed to have about the same tension and the two back the same. The tension front to back had to be different because the column with all the weight is at the back.

Then I tightened the two middle screws trying to keep each side the same until a saw a little movement on the level placed crossways on the table as one side was tightened slightly more than the other. I took this as an indication I had gone too far and then went back until the level returned to its earlier indication.

You should be able to do something similar with your lathe.

[John3]

I too recently leveled a VMC with 6 pads.

The reason I'm being so concerned about something that I once thought to be nearly trivial is that the Milltronics manual had very specific instructions about setting the pads.

Their leveling procedure involved checking head TRAM (Z-Axis perpendicularity) with the table, and adjusting errors with it via the leveling screws !!!!

The manual states; "6. Using a magnetic base with a dial indicator sweep the table to check tram. The tram should sweep withing 0.001 over a 10" diameter sweep. Adjust the leveling pads as necessary......."

They even have a chart in the leveling section to record table to spindle tram over 8 45 degree increments.

-John

[Geof]

I didn't mention it but I did check my machine at a later date and it was within much less than 0.001" over about 10 inches. I suppose I could have done the check when levelling I just never thought about it .

On small machines levelling is maybe not that important because they are not large enough and heavy enough to distort themselves. I have several Haas MiniMills and the manual says just that... don't worry to much.

I think your lathe is just a bit over the borderline into not small so it is worth worrying.

I just remembered a procedure from one of my other mills. Level it then with the level on the machine move it through the extremes of travel and see if the level defelcts during the movement.

You could try running the carriage slowly back and forth with the level on it to see if it is level okay at the ends and not twisted part way along.

[NC Cams]

Get a good machinists level - ours is a Fowler and is rated at 0.0005" in 10".

When you set it on the ways (both lengthwise and cross wise), you can literally watch the thing move when you simply nudge the adjusting screws.

We used this on/with our cam grinder (the table on it is 1500mm long which easily matches that of almost any lathe). With time and care and a bit of runing around the device, we got it level 14 ways toward sundown and only spent a couple hours doing so and we had 8 leveling screws to work/deal with.

Comparatively speaking, a lathe would/should be quite easy with especially with the comparatively smaller footprint to deal with.