# Angle cube accuracy?



## cdhknives (Jul 15, 2013)

I saw these being sold in the classified of this forum and had one question.  Are they accurate enough (really repeatable enough, yes I am VERY well versed in the difference) for lathe setup/bed leveling?  The magnetic base and fractional reading sure sounds like the perfect thing for just that...IF it is repeatable.

http://www.amazon.com/iGaging-Angle...1373935460&sr=1-1&keywords=digital+angle+cube


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## Ray C (Jul 15, 2013)

Hi...

I don't know about those electronic levels but, I had one similar.  After one use, I removed the battery (for other use) and threw the unit away.

If you're interested in aligning your lathe, making it level to the horizon is a tiny part of the equation.  In my case, I used a carpenter's level to make it just unlevel enough so fluids would gently travel to a desired part of the drip pan.  After that, the Rollie and 2-collar method was used to adjust the lathe until it cut perfectly.  If you're so inclined, the thread provided (albeit lengthy) shows the trials and tribulations of building a heavy bench and getting the lathe aligned.  It also shows links to the threads that Rich King posted about a different example case of using the 2-collar method.

http://www.hobby-machinist.com/showthread.php/10957-YALB-(Yet-Another-Lathe-Bench)?highlight=Yalb


Ray


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## cdhknives (Jul 15, 2013)

My bench is the same 50 year old welded angle frame similar to the one in your link.  I dunno who made it but it weighs more without any drawers installed than the lathe.  Mostly I'm looking to check for twist in the 54" long bed of my lathe.  I would have to use shims to adjust it out...  My setup was basically to bolt the lathe back in place with the same lead pads as before, use the adjustable feet to level against a 36" carpenter level, and start cleaning it up for use.  I've never checked the setup beyond that leveling and the alignment bar.

My 12" alignment bar is now reading about 0.0005" difference between ends, so I'm satisfied with that...but the only way I know of to check for bed twist is precision levels.  I am hoping the little cube is repeatable enough to zero at one point of the bed, move to another, and get a decent check on the angle difference between the points (and thereby verify that the bed is flat end to end).


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## Ray C (Jul 15, 2013)

Rich King is more qualified to talk about this but, in my view of the world, if the lathe cuts dead-on, I wouldn't care if the bed looked like a pretzel...

Unless I'm completely missing something, the whole purpose of the 2-collar and Rollie methods is to tweak (aka twist) the bed until it cuts right.

In any event, I think you'll need a precision level to do the kind of checking you're after.  I have a precision level from Shars which was 50 bucks.  It's normally not shown in their catalog but, if you call and ask Brian, he knows how to look it up.

Rich or someone else really needs to advise you on anything more involved than Rollie or 2-collar.  If you have questions about those things, I can offer what I know.


Ray


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## awander (Jul 15, 2013)

Usually, accurately leveling a machine tool involves using a level such as the Starrett 199Z Master Precision Level, which is specified as accurate to 10 seconds of angle, and has divisions which represent .0005" in 12". Those divisions would correspond to an angle of 8.59 seconds. 

Even the less-expensive Starrett 98 series levels are graduated in .005" in 12", or about 90 seconds.

The electronic level you are looking at says it is accurate to 0.2 degrees, which can also be written as 12 minutes of angle, or 720 seconds of angle. This corresponds to about .04" in 12".


I'd have to say that if want to do carpentry, that electronic level would be adequate, but not for leveling a machine.


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## 12bolts (Jul 15, 2013)

Hi ya,
If that is Pb you are referring to then I dont think it would be suitable as shims. The lead will just compress until it is carrying no weight.


cdhknives said:


> ....... basically to bolt the lathe back in place with the same *lead* pads as before, ........


And like Ray says,



Ray C said:


> .... if the lathe cuts dead-on, I wouldn't care if the bed looked like a pretzel.....



Dont get lost in the jungle trying to get a lathe level to the horizon. It needs to be straight and flat to turn parallel but not necessarily "level"

Cheers Phil


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## awander (Jul 15, 2013)

I know there are strong feelings, both ways, on the leveling of lathes and other machine tools.

There are those who say that all lathes must be leveled, and won;t cut a darn if they are not. 

Others point out that lathes are used aboard ships, where they will rarely be level, at least while at sea.

As pointed out, the lathe bed needs to be straight and flat in order to cut true.

In my opinion, the easiest way to ensure that a lathe's bed is straight and flat is by using a level. And it is easiest to then level the ways, instead of adjusting the lathe so that it is "out by the same amount" at both ends.

If you do level your machine, many setups will be made easier as well, as you can just level the workpiece and know it is square to the machine.


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## TOOLMASTER (Jul 16, 2013)

there are apps for iphones, if you have one


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## raross61 (Jul 16, 2013)

awander said:


> Usually, accurately leveling a machine tool involves using a level such as the Starrett 199Z Master Precision Level, which is specified as accurate to 10 seconds of angle, and has divisions which represent .0005" in 12". Those divisions would correspond to an angle of 8.59 seconds.
> 
> Even the less-expensive Starrett 98 series levels are graduated in .005" in 12", or about 90 seconds.
> 
> ...



I also feel the same as you, and Ray do, I have 2 of these one better quality, and one cheaper one, really cant see any difference between the 2 of them! Not sure I have anything good to say about them in a "precision machining environment". Now the rest of the story, when I was building my dump trailer and rotating it a lot on my overhead crane in my garage, it worked great, by using the zero function, even if the trailer was not level, you could zero it, and then install uprights, brackets, etc., and for a dump trailer .04 on uprights is fine.

Even at work in the heavy equipment business, where I do a lot of line boring on huge pin bores, some 110 MM plus. We made a extension for our inside micrometer, to check between another pin when the holes are all hogged out! I took my levels and played with them a little, but when you have a 55' logging boom and stick, off very much, it plays hell on the cylinder lift pins on the boom, so I was scared to trust it. In the old days we used spherical bearings, due to production tolerances, and it would go, Now we use some high tech bronze bushings, they have many holes in them, with some high tech, moly, or graphite pucks laminated into them, they won't take much misalignment! 
                                                             Bob in Oregon


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