# Model number for level



## DavidR8 (Feb 26, 2020)

This came up for sale near me.
Curious what model number it might be. Ad says Starrett 12" but nothing else.
Wondering if it might be sufficiently accurate for lathe bed levelling.


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## francist (Feb 26, 2020)

Looks like a 98-12 to me, and many will say not sensitive enough for machine levelling purposes. I have the little brother, 98-6.

-frank


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## NCjeeper (Feb 26, 2020)

Yeah. I have a 98-8.


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## Liljoebrshooter (Feb 26, 2020)

I would grab that up in a minute depending on price 
Joe


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## DavidR8 (Feb 26, 2020)

Thanks Frank, I think you’re right on the model. Starrett specs say that it has graduations of approximately .005 per foot. 
What level of precision is necessary to level a lathe?

Edit: asking $100
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## NCjeeper (Feb 26, 2020)

That's a good price. I paid 75 for my 8" without the factory box.


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## middle.road (Feb 26, 2020)

Close enough for the equipment you have, plus you still have 'young' eyes.


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## C-Bag (Feb 26, 2020)

Grab it quick! Ive got a 98-12 and the next level up precision 12" .0005per ft made in Poland and IMHO you need both and the 98-12 will a fine job of leveling. But I love my 98-12, must have, for me.


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## mikey (Feb 26, 2020)

Dave, be careful to look at the condition of the base before you buy that thing. If it is rusted or dinged up, pass. 

A Starett 98 is a good level but, in my opinion, lacks the sensitivity you need for leveling machines. I own a 98-6 and I use it but only to get me in the neighborhood so I can use my more precise level. 

What is the difference? Speed. A precision level will get you very near dead level very quickly. You still need to do a 2-collar test to finalize your level regardless of the level you use but a precision level will usually get you within 1/8 turn of a leveling bolt of foot.


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## Dhal22 (Feb 26, 2020)

A shame you couldn't use water as a level.   I do in my line of work (plumbing) and results are indisputable every time.


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## DavidR8 (Feb 26, 2020)

Score!
It’s basically brand new. 
He also had a brand new 196B1 indicator. 
All in for $200























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## BrentH (Feb 26, 2020)

Hey David, 

Check out e-bay for Starrett 196 accessories.  I got the full kit for $45 CDN the other day - shipping was a killer though, but still under 100 all in


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## DavidR8 (Feb 26, 2020)

I actually have the full kit but was missing the indicator. 


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## Shootymacshootface (Feb 26, 2020)

I love the 196 for tramming.


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## DavidR8 (Feb 26, 2020)

Shootymacshootface said:


> I love the 196 for tramming.



That’s the main reason I bought it. 
What does your setup look like?


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## Shootymacshootface (Feb 26, 2020)

I have a complete set in the wooden box. It has 2 rods a bar and a lever to use it like a test indicator. The large dish button on the back is great for getting over the t-slots, and with the dial facing up it makes it super easy to read.


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## graham-xrf (Feb 27, 2020)

DavidR8 said:


> Thanks Frank, I think you’re right on the model. Starrett specs say that it has graduations of approximately .005 per foot.
> What level of precision is necessary to level a lathe?
> 
> Edit: asking $100
> Sent from my iPhone using Tapatalk


Dave - look hard again at the 0.005, and check it did not say 0.0005 per foot.
The "three zeros with a 5" is the very common accurate machinists level.

The forces from being out of level getting to be sufficient for the big chunk of steel to develop a "twist" become insignificant, even from a "lower accuracy" level. Using a level for _measurement_ is a different matter.

Strictly, the lathe bed does not need to be exactly level as such. What is essential is that it be at _the same_ level across the ways. If you do choose to set the whole thing without twist AND horizontal, and you know there are reference unworn surfaces, it can be a great convenience if you want to use a level for measuring.

Try some numbers:
0.005"/12" = 4.1666E-4 gradient.
From arctan(4.1666E-4), that is 0.0238732 degrees.
Then to get angle in arc-seconds, multiply by 60 x 60
0.0238732 x 3600 = *85.94* arc-seconds

That's about twice or three times as good as a very high quality builder's level, and should be good enough for leveling a lathe, but maybe not for measuring.

For measuring, as in checking for twist, or attaching to a Kingway, I am not sure I would be happy with something as much as 5 thousands out only one foot away. That is why I asked about the "extra" zero.

The levels on eBay usually come as 0.0005" per foot, and 0.0002" per foot.
They also come as 0.05mm per metre, and 0.02mm per metre.

The angular values are ..
0.0005"/foot --> 8.59 arc-seconds
0.0002/foot  --> 3.43 arc-seconds
0.05mm/m  --> 10.31 arc-seconds
0.02mm/m -->  4.12  arc-seconds

I think the 0.0005"/foot and the 0.05mm/m are the most useful and usable, around 8 to 10 arc-seconds.
That is accurate enough for most measuring, and difficult enough to get them to "settle".

With my ambitions to knock up a sort of Kingway, I have purchased a couple of 0.02mm/m.
I was going for maximum sensitivity for the price, and I may regret it!
THESE -->  eBay LINK

4 arc-seconds may be "too sensitive". My experiences with trying out the level in the picture is that each measurement takes a up to half a minute to settle, and even leaning not very hard on a strong bench made with steel legs and frame, and a thick top covered in 3/16 steel, will still move it 2 or 3 divisions.


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## C-Bag (Feb 27, 2020)

The Starrett 98-12 is calibrated for .005 per foot. You can do a lot of fairly precision roughing in with it easier than chasing your tail with the .0005 per inch right off the bat. Personally I think it's good to have both and to know how to use them.


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