Just bought a Starrett 6" machinist level (lathe leveling)

RJSakowski said:
High sensitivity import levels are available for less than $100.
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8'' Precision Machinist Level Engineers Bar Inspection Block 0.0005''/10'' | eBay

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Ok, I cancelled my Amazon order and bought this instead. It'll take a month to get over here, though. Probably has to be shipped from China

I'll be happy with .0005 over 10"
 
I love John as a good friend, but I say you can use a .005" level to level align a lathe bed. If the bubble division is say 1/16 wide and 1 line is .005" then if you adjust the leveling screws or shim under the feet so the bubble repeats to the same spot then your with-in .0005". 1/2 a bubble line out is .0025, a 1/4 out is .00125, etc. I have used a magnifier glass to get it closer.

Normal spec. on a new machine is .0002" per 12" accuracy and on a old one are worn more then that, so why get that upset if center to center is 24" when new machine accuracy is .0004" If you can level it to with-in 1/2 a bubble on a .005" level on a worn machine what can you expect? Once you have the bed as level as possible with the .005" level you do test cuts or what is called the 2-collar test to tweak it in.

This part is bigger then your small lathe, but it shows how to do it. https://www.youtube.com/watch?v=XZP0o06gsco&t=571s . You can use a 1" x 3" between collars on a piece of aluminum I showed Adam (abomb) how to do this as other students. John or Benchee has attended what 4 of my classes as a student and quest as he has forgot more about machine shop then most will ever know. Some folks can't afford the expensive levels and the cheaper levels will get you close. Here is another one I showed Stefan G on Tail Stock alignment. https://www.youtube.com/watch?v=bLn0Ch1_KQM
 
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If it's .005 per graduation mark on the vial, it shouldn't be an issue then. If your bubble is visibly right on the same line on both ends of the lathe bed, then it should be less than 1/10th of .005 difference.
 
For those wanting to buy machinist levels I would recommend putting a want to buy ad on Craigslist. I was able to buy a 12” starrett 99 and 199 for $85 and $235. Boxes were less than mint but the levels are mint. Many times these are bought and not used much. I would pass on eBay for something like levels. Too many people buying things and reselling them. Using black sharpie to cover up dings and scratching out initial sand seeking in like new condition.
 
A few points concerning level calibration. First, level vials are one of two deswigns: the vial interior can be barrel shaped or a slightly curved cylinder. The former is now used in most modern carpenter's and mason's levels because the vial can be rotated around its axis and not lose accuracy. The curved cylinder was formerly used in all levels and is used in precision levels. If the level is tilted to any great degree, it loses its calibration. For this reason, cross vials are incorporated in precision levels. Why is this important? Because if the vial is tilted due to a surface with an out of level condition in the direction perpendicular to the calibration line, it will affect the calibration. Note that this is not a sensitive adjustment. My level's cross vial has a sensitivity of around .025"/10" or 1/50th that of the main vial.

While it is not necessary that a calibration surface not be a level plane or even have a level line, as has beeen noted in previous posts, it is desirable to have as close to level a surface as possible. Another issue is one of surface flatness. When trying to calibrate a level with.0005"/12" sensitivity, surface imperfections on the order of a fraction of a thousandth can affect the calibration process. Most surfaces that I have run across do not have that level of flatness. To that end, I would suggest that a surface plate be used. If a surface plate is not available, a suitable calibration setup can be made using two vee blocks, two dowel pins or pin gages, and a straight bar. A straight bar slightly longer than the length of the level is clamped to a flat surface. The surface can be the bed of a mill. The two vee blocks are set on the surface with the vees perpendicular to the bar and the ends of the block against the bar and the center to center distance about a inch less than the length of the level. Two dowel pins are placed in the vees and the level placed on the pins with the side of the level flush with the ends of the vee blocks. This provides a stable and reproducible alignment setup. If pin gages are used, the pin diameters can be selected to bring the contact surface close to level, less than .002"/12".Level Calibration Setup.JPG
 
It was delivered yesterday afternoon, but someone stole my UPS package.
 
I'm sorry you lost your find.
 
Contact UPS and tell them as they do offer insurance up to $50.00 I think.. Also call and report it to the local police. See if you can have it shipped to local UPS store and you can go there to pick -it up.
 
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