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  • Level Calibration

    Anybody know the procedure for calibrating this level?




    Last edited by Spindle; 08-06-2009, 08:25 PM.

  • #2
    Ah, the nuts raise and lower level. You need something flat which you can create by getting bubbles in same relative position when you turn level 180 degrees.

    Basically you need to level your reference surface by alternating comparisons of level at 0 and 180 while tweaking the level.

    When you are done doing this recursively, you will have a level surface and a level that is calibrated. Somebody save me, I'm not doing a great job explaining it tonight.

    Clutch
    Last edited by clutch; 08-06-2009, 08:31 PM.

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    • #3
      Clutch-

      I had the instructions, but lost them. There was mention of adjusting so the bubble read level when turned 180 degrees, then wait for 5 hours to use or adjust again.

      I understand the adjusting part, but don't know what the 5 hour wait was for. Thermal equalization? There was also a warning about keeping your hand away from the vial for thermal reasons.

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      • #4
        It never takes more than a minute for my levels to stabilize the bubble. It is important to clean the surface of the level and the place you put it down. Always place it in the same spot when you switch it end for end.

        The place you use to adjust the level doesn't have to be perfectly level, you just have to get the vial set so the bubble is off the same each time you swap ends.

        Truing a level is a learned skill and only by doing it many times will you get it right. Keep playing with it and you'll get good at it.

        5 hours? the guy must have been smoking a left hand cig.
        It's only ink and paper

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        • #5
          Clean the level and the surface it is to be set on. Set level on surface. Using a fine pencil draw around level. look where bubble is at, now turn level 180° place in pencil lines and see if bubble is in same place. If not it is time to adjust.
          The level is sensitive to heat, sun light, your hands, or leaning on the surface.
          When you are finished put your hand on one end and watch the bubble move as the level heats up.

          Bob

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          • #6
            5 Hours

            HA HA 5 hours well it does affect the level. If you are usiong the level and its out and you diont want to really level your customers machine perfect just with youre thumb gently rub the glass level opposite the bubble and it will work its way towards you LOL It has alcohol in it and this is a millwright trick to make it move a hair .

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            • #7
              Leveling a level

              This will do it.

              To fit a reference for setting the level to be calibrated, I use a good (1mm/1metre = 1:1,000 = 0.057 degrees = 3.44 arc minutes) carpenters level made from extruded aluminium and machines flat and parallel and set it in my vise.

              The procedure for setting up the OP's Machinist's Framing Level is here - its quick and accurate. It takes a bit of time at first but once you see how it works and are in the "swing" of it, it is quite quick.

              http://www.leveldevelopments.com/PDF...structions.pdf

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              • #8
                Originally posted by Spindle
                Clutch-

                I had the instructions, but lost them. There was mention of adjusting so the bubble read level when turned 180 degrees, then wait for 5 hours to use or adjust again.

                I understand the adjusting part, but don't know what the 5 hour wait was for. Thermal equalization? There was also a warning about keeping your hand away from the vial for thermal reasons.
                I'm over here near Buffalo New York. Let me know when you're going to use it and I'll have the wife turn off the oven.
                - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

                It is true, there is nothing free about freedom, don't be so quick to give it away.

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                • #9
                  Clutch, didn't read your unedited post, but what I see explains it pretty well.

                  With a sensitive level you discover gravity exerts a greater pull in some places more than others.

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                  • #10
                    Spindle, the 5 hour wait is for the level to come to thermal equalibrium. It's very difficult to adjust a level without handling it thus warming it from the heat of your hands. The heat input is naturally localized abd often the level setting is affected by unequalized expansion.

                    Few people will realize that their warm hands have such an effect on a sensitive instrument so the manufacturer solves the problem by an arbitrary 5 hour rule.

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                    • #11
                      Yes, body heat affects the level and that is why it's best to use a finger and thumb on each end to lift and move the level rather than a club handed grab of the level.

                      Your tools should be at the same temp as the machines because they are in the same building so all you need to do is keep the body heat out of the level or any other measuring instruments.

                      You might want to set the level on the mill table and leave it for an hour but not 5 hours unless the level is huge or just carried in from outside. Go to HF and buy the cheap non contact temp reader to check the temp of your work and measuring instruments. I have one and it is very handy in my shop. I use it all the time. I am going to get a more expensive one that reads higher than the 230 deg of my current one.

                      Some common sense has to be used.
                      Last edited by Carld; 08-07-2009, 11:03 AM.
                      It's only ink and paper

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                      • #12
                        Is this level going to be used to seek such a degree of precision that you're going to wait 5 hrs each time you handle it?
                        If not, what's the point of such painstaking calibration process?

                        Brings to mind the old line of "...measure it with a micrometer, mark it with a piece of chalk, then cut it with an axe... ."
                        Lynn (Huntsville, AL)

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                        • #13
                          Originally posted by lynnl
                          Is this level going to be used to seek such a degree of precision that you're going to wait 5 hrs each time you handle it?
                          If not, what's the point of such painstaking calibration process?

                          Brings to mind the old line of "...measure it with a micrometer, mark it with a piece of chalk, then cut it with an axe... ."
                          While being used to level a machine, the level would be handled frequently and probably would NOT be in thermal equilibrium. This is a practical necessity. To compensate for this, you should handle it as little as possible (someone above suggested using both hands, thumb and finger only, on both ends) AND reverse it to take readings both ways. You should reverse it several times and look for a reading that is consistently off in opposite directions (toward the same end of the level, that is). In this manner, you can, at least to a great degree, negate any errors that have been generated by uneven thermal expansion.

                          However, when setting up (calibrating) a level, you would want the best possible accuracy. If it is distorted by uneven thermal expansion, then you would be setting the zero to the wrong point. The only way to achieve that “best possible” zero setting would be to completely eliminate any thermal expansion and that means allowing a long period for it to stabilize to room temperature. It would also mean that extraordinary measures (hands off) should be taken to maintain that condition during the procedure.

                          So it does make sense. As for the five hours, it may or may not be necessary to wait that long, but such a time will insure that equilibrium is reached so they use a number that will always work and not just sometimes.
                          Paul A.
                          SE Texas

                          And if you look REAL close at an analog signal,
                          You will find that it has discrete steps.

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                          • #14
                            Originally posted by Forrest Addy
                            Spindle, the 5 hour wait is for the level to come to thermal equalibrium. It's very difficult to adjust a level without handling it thus warming it from the heat of your hands. The heat input is naturally localized abd often the level setting is affected by unequalized expansion.

                            Few people will realize that their warm hands have such an effect on a sensitive instrument so the manufacturer solves the problem by an arbitrary 5 hour rule.

                            Wool gloves? Seems like I recall a metrologist talking about wearing wool gloves to insulate body heat from the instruments...?

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                            • #15
                              Or heat your entire workshop to body temperature
                              Peter - novice home machinist, modern motorcycle enthusiast.

                              Denford Viceroy 280 Synchro (11 x 24)
                              Herbert 0V adapted to R8 by 'Sir John'.
                              Monarch 10EE 1942

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