Model number for level

[DavidR8]

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

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[BrentH]

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

 

[DavidR8]

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


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[Shootymacshootface]

I love the 196 for tramming.

 

[DavidR8]

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]

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.

 

[graham-xrf]

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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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.

 

[C-Bag]

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.