Lathe installation without a precision level?

[Ray C]

Rich,

I think this is what you might be talking about. See this post: http://www.hobby-machinist.com/showthread.php/10476-Triangular-Leveling-Base If this is not the correct concept you were talking about then please say so, so I don't misguide folks.

I built these because the edges of my garage floor are sloped a good inch at the sides (presumably for water runoff). These mounts worked very well for me to get the base close to being leveled. I ended-up building a heavy duty bench and moving it further back from the wall where the floor was not so horribly sloped.

Ray

You can solve the problem of the sloped floor by using 3 points under the cabinet (Kinematic mount principal). Many machine tools sit on 3 points to eliminate twists. In a shop I am rebuilding a grinder at has issues with a rough floor, so they used leather super glued to steel plates so the plate would not slip, if you want to spend some money you can buy wedge leveling mounts (http://www.reidsupply.com/products/leveling-devices-vibration-control/machinery-leveling-mounts/) . Place them under the lathe cabinet; put 2 under the head-stock end and one under the end of the Tail-stock end.

Moparfever for your information I am a Journeyman Machine Tool Rebuilder, have been aligning and leveling lathes for over 40 years, I manufacture machine levels and teach way scraping and rebuilding / building and have probably rebuild or helped build new machines, (a good guess would be) 1000 lathes and level aligned 5000 lathes in my career. Turning a test bar is the easiest way and most precise method as it duplicates the actual cut you're making when it's being used. (even if the ways are worn) to do this with and with-out a level!. Like I said before, I'm trying to help you with proven methods and not guesses. If you want to experiment to satisfy your curiosity go for it, but don't tell someone it won't work as I know it will !!. I was taught this method when I was an apprentice and it works. Many new machine builders tell their customers to use it for the final test after leveling. I can send you a pdf on how to do it if you PM me your Email Address. I can also send you the info we use to align tail-stocks and turrets.

 

[hobbygunsmith]

Test bar ---TT------TT-------TT-- after getting it close with plate glass and ball bearing, optional buy a used level. I have enjoyed all the different ideas proposed. Three point floor mount? I have used this on a small lathe's bench.

 

[Richard King]

Test bar ---TT------TT-------TT-- after getting it close with plate glass and ball bearing, optional buy a used level. I have enjoyed all the different ideas proposed. Three point floor mount? I have used this on a small lathe's bench.

3 points is used by Moore Jig Bores, Sip Jig Bores, Granite surface plates, several brand surface grinders, Think of a transit or a camera tri-pod..3 legs = 3 points so it doesn't rock or in machine tools, twist.

Toz, Rays idea is not what I was thinking of, but it's a good one. I see on Ebay you can buy a new import .0005" level for $80.00. There are several used Starrett levels there too.

It does sound like your having fun with the laser level. I will shut up now. If you need anymore help of info from me. PM me. I will send you the 2 collar test pdf as soon as I get into my office where I have it on that PC.

Rich

 

[Metalmann]

"Turning a test bar is the easiest way and most precise method as it duplicates the actual cut you're making when it's being used. (even if the ways are worn) to do this with and with-out a level!. Like I said before, I'm trying to help you with proven methods and not guesses."





I'll back you up on this post, Richard.

Besides, a 36" long lathe bed isn't that much to worry about.

Now, when I installed lathes over 25 feet in length; that was a different animal.

Those boys have to be spot on. Some of them were a lot easier to tweak, than the shorter machines.

When the poured foundation is done, you will have to spend the next few years "tweaking the twist".

Then others, hardly ever needed adjusting.

What's more important, is the relationship of the head, to the ways/bed....then the tailstock.

 

[tigtorch]

Interesting test, Tozguy. On a lathe bed the overall flatness of the level would be less important because it would only contact the bed in just discrete areas. I hadn't expected someone to try this, I defer to the experts in really leveling a bed, I was posing a logic exercise.

 

[Richard King]

Hi Richard, I'm well aware of your qualifications, and wouldn't go against your recommendations. However, on my lathe there is so much wear within the 10" near the headstock that I get .0004" difference from one end to the other. The rest of the bed shows little wear. Do you really recommend I adjust this out by twisting the bed? Then the rest of the bed will be out of wack. Of course I do turn more parts within that 10" than anywhere else, but doing what you say doesn't sit well in my mind. If you say it's a viable method in my case then so be it. Like you said, I have little experience compared to you.

I have twisted beds for years to compensate for wear. Taz never said anything about wear near the chuck did he? There are many factors when twisting the bed. I ask the lathe owner if he uses a boring bar to bore holes or just turn? As If you twist the bed for the OD the ID bore will be off or you can go 1/2 way. When its off one has to file or emery cloth the part if he wants a straight part.
so if you can twist it to help the situation and not cause other problems, go for it.
But this was not the original question. It was how do you level a lathe with-out a level. The 2 collar test has been used for years to do this. It's not my idea, it's an industry standard taught and recommended by professionals and instructors. If one can't afford to get the machine rebuilt he needs to "Tune it up" and utilize some "tricks of the trade" to turn better parts. We are here to learn and not debate. I found the thumb bob idea to be interesting.

 

[Ray C]

Just mentioning I find this thread very interesting and appreciate everyone's input, creativity and willingness to pass-on industry experience...

I've been setting-up a benchtop lathe in the last few weeks. The effort is taking longer than hoped due to various delays and other work cropping-up but, I must say this... It has been a learning experience!

I've tried some (but not all) of the techniques mentioned here and they did not at all produce the results I was expecting. -And I believe the reason for that is because there are different kinds/styles of lathe for which some techniques are applicable and some are not. I'm not stating that as fact -as I have no business making such a statement but, all my experiments and theories are leading me to think this way.

For Example: A modern table-top 1000lb 12x36 lathe has a different bed and footing configuration than say, a heavy 10. Putting shims under one leg of the benchtop does virtually nothing while the same shim under the leg of an H10 will change things considerably. Of course, there are MANY different styles of lathe and I really think that analysis is needed for each individual lathe, to determine how best to set it up.

Sorry, I don't mean to hijack this thread... I didn't really have any point to make by posting this but, somehow had to get it off my chest. Fire away and tell me if I'm full of crap. At the end of the day... I just want my lathe working good so keep talking so I can try different things.


Ray

 

[Tozguy]

First, I want to apologize for not being clear enough in my original post. My question was about how one might get along without a machinist’s level with respect to detecting twist in the ways during installation. Getting the whole lathe absolutely level was never a biggie for me. My assumption is that a machinist’s level would be used at both ends of the bed to compare readings during the installation. It is NOT about trying to replace the bar turning procedure that is the ultimate and final test for detecting twist in the ways. Before writing the original post I was fully versed on the twin hub test bar turning procedure and its variations. It is in every manual I have consulted and it is all over the web. I fully intend to use this fundamental procedure for final adjustments. As much as I appreciate the participation, proposing this method to me is like preaching to the converted.

Second, some stuff I don’t know. The new 13x40 gap bed lathe I have ordered comes with a stand. The stand is basically two steel cabinets with a steel sheet bolted across the back of the cabinets to tie them together. Each cabinet has four mounting holes in its base. It does not strike me as being a very rigid structure. It is going on a sloped cement floor. What should be done to check straightness and levelness of the stand before plopping the lathe on it? Will the bench top lathe come straight or twisted? How rigid will it be? Without a level do I just slap it all together and rely on the test bar turning procedure to make all the adjustments for twist?

Third, I’ll buy a machinist’s level if I need one but do I really need one to install a lathe? The executors of my will already have enough to liquidate when I go to the big machine shop in the sky.

Yes, I am in this for the fun of it and I'm having a ball. Getting the most out of what I already have is part of the fun. One thing I have too much of is time. Waiting for the lathe to arrive is painful. Hopefully it will arrive before I drive everybody crazy, myself included.

Ray, glad to know that I am in good company. Please make whatever you want out of this thread, we are in the same boat.

Richard, you can call me Taz if you want as long as you don’t mean anything by it. J

Regards to all and thanks again for your help.

 

[Ray C]

... Stuff snipped...

Second, some stuff I don’t know. The new 13x40 gap bed lathe I have ordered comes with a stand. The stand is basically two steel cabinets with a steel sheet bolted across the back of the cabinets to tie them together. Each cabinet has four mounting holes in its base. It does not strike me as being a very rigid structure. It is going on a sloped cement floor. What should be done to check straightness and levelness of the stand before plopping the lathe on it? Will the bench top lathe come straight or twisted? How rigid will it be? Without a level do I just slap it all together and rely on the test bar turning procedure to make all the adjustments for twist?

Third, I’ll buy a machinist’s level if I need one but do I really need one to install a lathe? The executors of my will already have enough to liquidate when I go to the big machine shop in the sky.

... other stuff snipped...


Regards to all and thanks again for your help.

Tozguy,

Please have a look here just to see what I'm up to. http://www.hobby-machinist.com/showthread.php/10957-YALB-(Yet-Another-Lathe-Bench)
http://www.hobby-machinist.com/showt...-Leveling-Base


So far, I'm making good progress and I think I'm about ready to finalize then, summarize all my steps so far. I've had many different projects going -all related to improvement on the lathe. The work has taken longer than hoped. With luck, I'll be finished this weekend.


Ray

 

[Richard King]

Here is one you guys with lots of time on your hands...lol....I was thinking today about a chapter in the Connelly book "Machine Tool Reconditioning" and they use water to test the height of the ways on a grinder by using clay to plug the ends and depth mic-ing to the water.. It's a bizarre, but back when the book was written maybe it was another idea someone had.

I was thinking for the fun of it get a clear plastic pan of water in it, and set it on the ways near the chuck and use a fine point pen and ruler or a scribe and mark the outside of the pan with a thin line. Then pick it up and careful move it to the tail-stock end check where the water is compared to the lines. I was thinking you could call it a "Leveling Bed Pan" :lmao:. I hope I didn't come off as preaching, but sort like the name Pastor Rich...:lmao: :lmao: