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ckelloug
03-17-2007, 01:19 AM
Hi y'all. This is my first new thread. I am curious how level one reasonably needs to get a taiwanese lathe and a real bridgeport mill respectively when setting them up. I've used these types of machines before but this is my first foray into owning and maintaining them.

It looks like a machinist level that does .005/foot is much much cheaper than one that is calibrated to .0005/foot. What would be the problems created by the machines being a touch out of level and what is considered reasonable?

--Cameron

J Tiers
03-17-2007, 01:26 AM
At the risk of repeating what has been said before.....

"Level" to that degree of accuracy is totally unimportant..........

BUT

"All parts alined the same" is pretty important on a lathe.

So the level with more resolution gives you a closer comparison of whether the headstock end is leveled the same as the tailstock end.

On teh other hand, the 0.005 level won't go crazy if a few microbes get under one end. it will get you close enough to do a "two collars" test, or the like, which directly measures alinement as it affects performance.

The 0.0005 level will drive you nuts getting roughed in. But it certainly is accurate..........

I don't think you need to sweat the Bridgeport..... they tend to be a one-piece lump that doesn't get out of alinement with itself.

Lathes, planers, etc are the stuff you need a level of some sort to get alinement reasonable on.

Carl
03-17-2007, 01:39 AM
We need to bring out the old Le Blond Portable early in the discussion this time...

http://www.lathes.co.uk/leblond/img14.gif

Evan
03-17-2007, 01:46 AM
How would you align a lathe in a microgravity environment?

Carl
03-17-2007, 02:19 AM
How would you align a lathe in a microgravity environment?

...with chains and binders.

ckelloug
03-17-2007, 02:34 AM
First of thanks Jtiers for the advice. I didn't go back to the 2005 thread and find the discussion until you mentioned that this discussion may have happened before as I hadn't been lurking that long. I've seen enough to know that as level as you can get it is the correct answer and that the reason to level is not due to level in the case of a lathe but ensuring that the bed is not twisted using parallism with the gravity vector as a measurement technique.

Of course the question is then if the north side of your shop has a vein of uranium ore and the south side doesn't then does the geoid variation between the north and south sides of the shop make the gravity vector point just enough off to drive the pedantic nutso:D

Well, Evan, I'd get out my 2 lathe sized surface plates from the locker where the frictionless pulleys and massless ropes are stored. I'd then make the surface plates parallel using stacks of perfectly accurate gage blocks from the same locker. I'd then sandwich the lathe between the plates with one plate pressed firmly against the bottom of the lathe and the other plate above the lathe spaced away far enough not to contact anything held apart by the three stacks of perfectly accurate gage blocks.

This would of course require adjusting the feet of the lathe to contact the bottom plate. I would then slide a laser phase difference of arrival distance measuring instrument along the top surface plate measuring the distance from the bottom of the top surface plate to the front and back lathe ways. Adjustment of the lathe feet against the bottom surface plate and thus rotation of the alignment of the top surface plate parallel to the bottom surface plate could thus be accomplished. When all the distance measurements are the same then the surface plates are parallel to the ways and there is not twist in the bed.

Ryobiguy
03-17-2007, 02:44 AM
Pretty clever Cameron... Finally a new twist on lathe untwisting. :)

I wonder how much the ways bow upwards if there isn't gravity holding them flat?

You'd need some serious chip control, and you'd probably want to get out of the way when starting or stopping the lathe.

On the other hand, why not just skip the lathe and pull the finished part out of your magic locker? ;)

Evan
03-17-2007, 03:04 AM
Don't laugh Cameron. :) I have done experiments with optical alignment on my lathe using a horizontal line laser and prisms to reflect the beam(s) on a wall about 25 feet away. It works quite well. I forget the exact math now for what I calculated as the resolution but I seem to recall I could resolve to about 20 arc seconds.

I haven't finished those tests as I was planning to use multiple reflections between first surface mirrors to make the path longer. I haven't tried that yet.

I forgot to mention that I used the prisms as corner reflectors sitting on parallels on the bed ways because that makes the horizontal alignment entirely non critical as it is irrelevant anyway.

J Tiers
03-17-2007, 09:50 AM
BTW..... for the amusing gentleman who "trumped the discussion" with the portable LeBlond..........

You will notice TWO things about it......

1) It sits on 3 supports, so there is no net force twisting anything assuming a sensibly flat and level floor. A sufficiently unlevel floor to give a twist would send it rolling into the corner with bad results.....

2) the bed on it is one of the stoutest you will ever see, ion proportion to length and size.... The prospect of getting a serious twist into that seems unlikely.....

ckelloug
03-17-2007, 10:42 AM
Carl. I want one of those portable leblonds. Just need a steam tractor to pull it.

Evan. In my brief time here, you worry me some days :D

loose nut
03-17-2007, 11:14 AM
How would you align a lathe in a microgravity environment?

Don't you watch Star Trek. First you have to set up an anchored warp field to stabalize the local space around it then set the inertial dampeners to maximum so you can use a wrench, take some superstrings to tie it to your skyhooks (only three never four) and adjust it in the usual manner.

nheng
03-17-2007, 11:30 AM
Warner and Swasey's turret lathe book shows this old precision level, good to 0.0006" per foot. You can see by the adjustment that level is not what they were after, but rather a tool to verify that all measuring points were in the same flat plane.

When you get finished setting up the lathe, you might even want to depart slightly from equal measurements at the ends in order to remove a slight taper. Before doing this, you'd have to make sure that the tailstock has no offset, or use a test bar cut while held only by the chuck. There are numerous threads on this topic that describe bar length, minimum diameter to avoid deflection, etc.

Carl, that's a good one. Reminds me of old radio flyer red wagons ... could've used a lathe back then :)

Den


http://img.photobucket.com/albums/v319/nheng/misc/warner_swasey_level.jpg

JCHannum
03-17-2007, 11:48 AM
The confusion results from the fact that people refer to "leveling a lathe", when in fact it is using a level to align a lathe.

The level is simply a convenient and relatively inexpensive means of comparing the relative position of various points on the lathe bed to each other. A surface gage and dial test indicator could be used to accomplish the same thing on smaller machines.

Swarf&Sparks
03-17-2007, 03:03 PM
"How would you align a lathe in a microgravity environment?"
I wouldn't bother, it's self-aligning :D

Paul Alciatore
03-17-2007, 05:49 PM
When it cuts as accurate as you need, then it is aligned well enough.

Your Old Dog
03-17-2007, 10:49 PM
BTW..... for the amusing gentleman who "trumped the discussion" with the portable LeBlond..........

You will notice TWO things about it......

1) It sits on 3 supports, so there is no net force twisting anything assuming a sensibly flat and level floor. A sufficiently unlevel floor to give a twist would send it rolling into the corner with bad results.....

2) the bed on it is one of the stoutest you will ever see, ion proportion to length and size.... The prospect of getting a serious twist into that seems unlikely.....

You have to admit it clearly demonstrates that you could park it on the side of a hill and do accurate work with it. I took that to be the meaning of the picture! But you are right of course, three wheels means it won't likely have any twist in it. But for most new folks they have to learn that the purpose of leveling is to insure the ways are not twisted.

Your Old Dog
03-17-2007, 10:51 PM
How would you align a lathe in a microgravity environment?

I'd use my old wooden Stanley level I use for sidewalks and defy anyone to prove me wrong !!

J Tiers
03-17-2007, 11:33 PM
Actually, parking the LeBlond on a hill, if it were restrained from moving, WOULD TWIST IT.

The single wheel would introduce a torque on the bed due to the direction of gravity not being alined with the axis of the support.

I doubt it would be very significant on any hill you could credibly park it. But attached to a wall, for instance, would have that proiblem.

That is assuming that the single wheel support was attached by "pinning" rather than a solid support point. Although even a solid support point would have a small but measurable deflection and torque on the bed.

Evan
03-18-2007, 12:11 AM
Hmmm. How would you do flood coolant in zero-gee?

ckelloug
03-18-2007, 12:23 AM
I think I'd see if the ship's vacuum toilet could be modified to constrain the flow. NASA guys are a bit pedantic so I would suggest urine as the flood coolant since they already know how to handle that. . . I'd ask the acquaintance I know that's in charge of building the machines that reprocess urine on the International Space Station but I think they'd throw me out of the supper club. Urine as a flood coolant might introduce extra phosphorus into the alloy ;)

Swarf&Sparks
03-18-2007, 08:49 AM
"so I would suggest urine as the flood coolant"
Nope, would introduce nitride hardening to all those exotic alloys.
They might get p1ssed off. :D

Evan
03-18-2007, 09:14 AM
Sorry about derailing this thread Cameron. Back to your original question, it largely depends on you and what degree of accuracy you desire. You can align the lathe plenty close enough with the less accurate level and then use test cuts to bring it in to whatever precision you require, within the capability of the machine.

Swarf&Sparks
03-18-2007, 09:21 AM
as long as the suds run down the drain and not over the side, it's level enough for me.
OK, that was facetious, but we're talking alignment, not level.
Good mate of mine (now deceased) ran machines on everything from submarines to bulk carriers. Marine engineer of the old school (Clyde)

Let's lay this "level" thing to rest for all time.
Vale Aldo

Evan
03-18-2007, 09:40 AM
Is Vale your name SS?

I was cruising at low altitude over your hometown last night. How does anyone get anything done there? It appears to be unfairly over supplied with golf courses and beach.

http://vts.bc.ca/pics2/perth1.jpg

Swarf&Sparks
03-18-2007, 09:52 AM
Rest, Aldo C

No you are well south of here Evan, try Cockburn Sound or Mangles Bay on google earth.
BTW, beware of assorted mililtary hardware around Garden Island :D
Airborne, surface and sub.
I'm about 32 17' S, 115 42' E
The Name's Lin, or Lindsay, if you prefer.

Evan
03-18-2007, 10:17 AM
? I use NASA World Wind, many more options. According to it you live about 35 kilometers off the coast then. :confused:

Swarf&Sparks
03-18-2007, 10:31 AM
Dunno, my chart's in nautical miles.
FYI, Aus 117

Swarf&Sparks
03-18-2007, 11:13 AM
This may help
http://i23.photobucket.com/albums/b387/idgara_eng/cockburnsound.jpg

ckelloug
03-18-2007, 03:27 PM
I have to say this has been a fun thread. I now know that as level as you can get it is the right answer for a lathe bed. The levity provided by the space lathes discussion was of significantly more value than the brevity of a concise "As level as you can get it answer." The question is, did the Japanese who did things like harden swords by plunging the hot sword into the living body of a captured opponent ever use urine for hardening ;)

Speaking of hardening, does anybody have a preference in bench furnace brands? I've been looking at a small paragon for my nefarious plans.

Evan
03-18-2007, 04:30 PM
I wasn't really aiming to sidetrack the thread when I mentioned aligning a lathe in zero gee. The point was to direct attention to the real problem at hand, alignment rather than leveling.

As for furnaces, I don't have one, yet.

Your Old Dog
03-18-2007, 04:37 PM
As for furnaces, I don't have one, yet.

Hey Everybody! Did you see that, Evan ain't got a furnace..........................yet ! :D

Evan
03-18-2007, 04:41 PM
That isn't quite true. I have a furnace for melting aluminum but I don't have a bench furnace for heat treating. Yet.

darryl
03-18-2007, 05:23 PM
Ok, if anyone goes so far as to find the molds for the LeBlond in the pic, put me down for a set of castings :) . Seriously, I think it'd be cool to own one of those. Has anyone here ever used one?

oldtiffie
05-14-2007, 04:32 PM
Deleted/edited-out