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Leveling a slant bed lathe

wrustle

Titanium
Joined
Jun 8, 2006
Location
Massachusetts
Can anyone please tell me how you go about leveling a slant bed lathe? Since there aren't any straight flat perpendicular surfaces to locate a level off of, what do you do? Is a simple matter of tramming in a straight rod in the chuck? Any insight greatly appreciated.

Best Regards,
Russ
 
Picture of leveling plate on turret. Level goes on plate, machine is moved in x,z and feet are adjusted till level.


OKUMA2_013.jpg
 
Roosta.

You'd have to ask yourself what the reason for levelling it front to back would be....
So the coolant doesn't poor out all over your toes.
Just kidding.

Being series. So you can see if there’s a twist in the bed. A cross level, front to back, will show any twist as you traverse the Z axis. So you can tweak up the balance front to back under the tail stock end, verses the Headstock end.

Debatable on a machine the size shown in that Pic. But on longer beds, that can definitely have a twist, that can be minimised, by taking cross readings, along the bed.

Cheers Phil.
 
I would like to say it don't have to be level.
Just has to be square within itself.
I would be tempted to use a test bar and an
indicator to check for squareness.
Now I will be quiet and let the flames start.
Regards Walt..
PS Should be setting firm w/no rocking.
Now let the flames begin...
 
Walt.

No flame wars. That’s true. It doesn’t have to be true level. But if you were to use a level. What would you do, shim the level, until your got a reading on the bubble, or adjust the machine till it was on the level plane?

On a side note. I was watching some Mazak techs a few months ago, doing a 12 month follow up, on a 6 meter H650e Integrex. Their preferred method was to take a sheet metal cover off near the milling head, lay some Play Doh down on some sheet metal guard, close to the head. Press the level into that until they got a reading, and proceed to tune the machine up, based on results coming from a level pressed in to Kiddies Putty, as they traversed the base.

It didn’t look that confident to me. That machine has never turned parallel also.

Regards Phil.
 
The one time that I saw it done by a technician installing a machine. He took a panel off the back of the machine close to where the slides are and there was a nice machined flat spot that I can only guess was meant for that, but maybe it does other things as I didn't have time to ask questions then. I don't know if most machines have some reference plane hidden somewhere in the back.
 
I can see why you'd level it end to end to keep the bar feed happy. Front to back though isn't that important on the level but the pressure on the feet is. I'd have thought a level on the top of the cabin would be close enough for front to back.
 
I leveled my machines by leveling off the Z axis rail and then used the level bracket to level front to back in X
Worked well
 
Hey guys, thanks for all the advice. Will put it to good use.....just got in a new precision level .0005"/10" so I will give it a go.

Best Regards,
Russ
 
Warner & Swasey always sold or issued a precision adjustable level with their slantbeds. They provided a leveling fixture to go in the turret to set the level on but it was not a precision piece of work. You clamped the level to it, adjusted the level to read level and adjusted the rest of the to read the same way.
 
Absolute level on the lathe isn't critical. It needs to be straight. Machtool is quite right. A twist in the bed, or a bow or dip, will change the tool tip-to-spindle centerline distance as the turret moves in Z. The guy running the machine sees this show up as TAPER.

I recently installed a new lathe that didn't come with a levelling plate (WTF was the factory thinking? Grrrr.) So, I came up with Plan B. We tack-welded a piece of flat stock to the end of a piece of round bar. The flat stock needs to be flat enough that the level won't rock on it. Mount the bar in a boring-bar holder, and get the plate as level as you can eyeball it in the cross direction. Mount an indicator so it is touching the top of the plate. Tram back and forth in Z, tapping the plate to get it parallel with the Z travel. (Hence the TACK welds. We don't need a lot of strength here.) Now, put the level on the plate crosswise and tilt the plate until the level reads close to centered. Relocate the level parallel to Z. Get the bed levelled in Z, then work on X. I use a 3-point method. Read the level at both ends of the Z travel, and the middle of the stroke. When the readings are the same, the bed is flat. When the level is crosswise, you can read it while the Z is in motion. If it changes, the bed has twist. Now, you get to figure out which jackbolts make what affect on the alignment. ;) It was crude, but worked just fine. Now, if I catch up to that shipping guy in Taiwan, he'll be sorry he didn't send the plate...
 








 
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