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Long lathe levelling

weedy64

Aluminum
Joined
Dec 12, 2005
Location
Langley, B.C.
I know this has been beat to death in general but the lathes in question are usually 60" or less in length.

I have a Monarch 612 25x144, 16000lbs. Is there a procedure somewhere that deals with large lathe alignment (its large to me). It has a 4 adj. feet headstock, a 4 adj. feet tail pedestal and 2 ea. - 2 adj. feet center pedestals. I have watched videos etc on smaller setups but am a bit unsure if it pertains to mine.

Im good with the 2 collar test and the align. of the tailstock to the headstock. But what/how do you test when the tailstock moves to the other end of the lathe 10+ feet away.

Initial level: Where do you start? 2 headstock feet and single point at the tail end like the smaller ones and add pressure to the center pedestals to remove sag.

I have a Starrett 98 and a 199 is that adequate or do I need someone with optical or laser.
 
The language confuses me slightly but basically you start by taking up the weight of the machine under the headstock using the inner adjusters, closer to the other end.The other 2/3 supports should rest on steel rods. Level and then move to the next support and then to the next one. Idea is to remove twist right from the start and follow the twist for there on. I can be specific with a picture. Then, you screw out adjusters which did not take up weight until a minute movement is seen on the levels. You want zero twist but you shouldn't kill yourself for "horizontal" unless you set up work with levels. The standard level in some places is a 0.02mm/meter or half that ( 0.01mm/meter ) . Better than that becomes very tedious and depending what's underneath, it won't stay put. It pays to plan ahead and move quickly - long lathes don't like to be left twisted one day to the next. If there is vibration around they can take a set. To repeat : say lathe has three "feet". Level headstock foot, level middle foot, level the last one. Bring carriage mid way and tweak slightly for it's weight.
 
Initial level: Where do you start? 2 headstock feet and single point at the tail end like the smaller ones and add pressure to the center pedestals to remove sag.

...in other words you start with headstock inner adjusters followed by the closest pedestal and so on.
 
I have a 2013x102 with a center support, my lathe is a series 62 with 6 points on the head. I have found that when I move it I just snug all the leveler and start at the the head with a 98 level. I check level across the ways then laterally. I get the machine rough leveled and wait a day or two before revisiting it. My floors are not smooth and even and trains rattle the place. After a couple days I go back and reassess the level, usually it needs a bit of adjustment but stays put after that. I recheck the machine after a week or so and periodically, maybe every couple months.

My lathe weighs less than your machine and with 12 points of contact well distributed, with that said, I made riser blocks 3" in diameter to bear the leveling screws on. They seem to apply the load force more consistently than a small point load.

Steve
 
I have a 2013x102 with a center support, my lathe is a series 62 with 6 points on the head. I have found that when I move it I just snug all the leveler and start at the the head with a 98 level. I check level across the ways then laterally. I get the machine rough leveled and wait a day or two before revisiting it. My floors are not smooth and even and trains rattle the place. After a couple days I go back and reassess the level, usually it needs a bit of adjustment but stays put after that. I recheck the machine after a week or so and periodically, maybe every couple months.

My lathe weighs less than your machine and with 12 points of contact well distributed, with that said, I made riser blocks 3" in diameter to bear the leveling screws on. They seem to apply the load force more consistently than a small point load.

Steve

Steve is spot on. Lathes this long and heavy have beds that sometimes act like spaghetti. They are amazingly flexible. I have a long and heavy L&S and all the factory manuals that go with it, including the installation procedures required. The manual first states that the lathe must be mounted on a concrete slab that has a minimum thickness of 8". Then starting at the headstock end, the bed is made level in both the x and directions, then the center support legs and lastly the tailstock end. Expect to do this back and forth many times before it seems straight. Wait a couple of days and do it again. After one month, check it again. Believe me, it moves about as it settles. I used 1/2"steel 4"x4" plates under the adjustment points to spread the load as well.
 
It has been sitting on pallets for 10yrs, so who knows if it has a "set", hope not or at least a straight one.

Yes, the base I forgot to give any detail.

The floor is +30yr old concrete of unknown thickness in an old building on a an ex-gravel pit. With the lathe came 4ea. 3/4" flame cut plates, the full size of each pedestal, head-stock foot and tail-stock foot. The 12 1-1/4 jack-screws all seat into OEM 3/4" x 5"dia ci disks that sit upon the steel plates. I do not plan to bolt the lathe down, but there are holes in each disk to do so if I find it necessary.

The plates are clean, the disks are clean, a little construction adhesive on the disks to keep them from skating under a vibratory cut might be in order.
 
Yes, plates....I forgot that detail.

The floor is +30yr old concrete of unknown thickness in a building in an old gravel pit. There are 4 ea 3/4" flame cut plates, the full size of each pedestal, head-stock and tail-base. The 12 1-1/4 jack-screws all seat into OEM 3/4" x 5"dia ci disks that sit upon the steel plates. I do not plan to bolt it down, but there are holes in each disk to do so if I find it necessary.

The plates are clean, the disks are clean, a little construction adhesive on the disks to keep them from skating under a vibratory cut might be in order.

The thickness of the concrete matters little. What's underneath matters a lot. Plates, etc just slow down things.
 
This is a good job for an autocollimator. If you align the autocollimator to the spindle axis, and you have a target that you can run up and down the bed, you can dial it in to under .001"
 
This is a good job for an autocollimator. If you align the autocollimator to the spindle axis, and you have a target that you can run up and down the bed, you can dial it in to under .001"

I think that's a great idea. That is how ship prop shafts are dialed in, but who has one just laying around?
 
I think that's a great idea. That is how ship prop shafts are dialed in, but who has one just laying around?
I've found them at very reasonable prices on ebay. Lots of optics equipment was discarded by aerospace, and there is a good supply if you are patient.
 
This is a good job for an autocollimator. If you align the autocollimator to the spindle axis, and you have a target that you can run up and down the bed, you can dial it in to under .001"

Well, you could dial it to a tenth of that but it's not going to help none. If the lathe has been sitting on pallets for 10 years things are not looking that great. My suggestion to the OP is to do exactly what I wrote - I did this once or twice. Maybe more than twice...

Just get a 0.02mm/m level and get started - it can take a while. FIRST you'll have to established if what's UNDERNEATH the concrete can carry the headstock. If it can't, then cut a square, dig to "hard" and fill with proper compacting then poor 4-500mm of concrete with the rebar low down. Keep it wet for two weeks. The headstock must be dead stable. The rest will eventually follow.
 
Well, the lathe has been sitting directly on the concrete in place for 3 mths. I lifted it on the w/e and placed the steel plates under it and cleaned\lubed all the threads on the adj. pins. and placed the ci feet under the pins as well. I roughed it in with the .005"/ft level and put some weight on all the feet. I will let it sit like that for a bit while I clean it up and wire it. My 123 blocks are a bit pitted and so I think they are not really up to the task with the .0005/ft level. A quick test with the sensitive level showed just how touchy the final adj. will be.

The 4ea head, foot adjusters all have a lock nuts, and there are separate hold-down holds in the bases. The two middle pedestals just use hollow bolts, bigger ones and I suppose if one bolted thru them that would lock them but I don't plan to pin this lathe down so I will have to "invent" something the keep them secured
 
I think you're on the right track but the thick plates might create a problem them selves. If they are not sitting on flat concrete they might rock on the high points while trying to adjust the levers? In other words adjusting on the near side may uncontrollably change the far side, a condition I call fighting a loosing battle. Now if they are grouted in with some high strength grout that fully supports the bottom side, that will fix that condition.
It may work better if you have smaller plates, one under each adjuster?
This is nothing new, lots of long lathes are set up but it takes more work to get the job done properly.
 
The floor is certainly not flat.. but so far the 3/4 plate just conforms to the floor with weight on the jacks-screws. A lighter lather could rock but this one bends the plates.. so far. I cannot slide a thin steel rule between the plate and the concrete anywhere near the jack-screws. The 4x4 headstock plate is the most likely offender and could be cut into a 4 12" squares to allow better conformity but the others seem good. Maybe I should ditch the plates and just use the OEM pads, I guess I'll see if I get too much interaction between adjustments or if things keep moving on me.
 
I think you're on the right track but the thick plates might create a problem them selves. If they are not sitting on flat concrete they might rock on the high points while trying to adjust the levers? In other words adjusting on the near side may uncontrollably change the far side, a condition I call fighting a loosing battle. Now if they are grouted in with some high strength grout that fully supports the bottom side, that will fix that condition.
It may work better if you have smaller plates, one under each adjuster?
This is nothing new, lots of long lathes are set up but it takes more work to get the job done properly.

It would appear that I am fighting it, started pulling out plates today, 3/4" they where just too springey and the big one would not conform to the concrete enough to be stable. I'll try again.

JL: thanks for the reference material
 
There is a product used in the ship industry that would be very beneficial for this task. When installing large ship engines and long prop shafts, the engine mounts and shaft bearing mounts are dialed in with an autocollimator and jacks. Then the actual mounts are dammed up and a special epoxy called in England "Chalk Orange" is poured under the mounts and allowed to set. This stuff doesn't shrink and works quite well. I used it myself when installing a long torque tube for the prop shaft knowing full well that if welded to the hull, the tube would distort.
 








 
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