No announcement yet.

On Making Level Vials...

  • Filter
  • Time
  • Show
Clear All
new posts

  • On Making Level Vials...

    Not wanting to high-jack the thread on fly cutting, but wanting to share this info.

    I found this page particularly interesting when I started down the path of making a precision level...

    I haven't had the time to try out the method they suggest, but it looked good.
    Obviously we would be making much smaller vials, but the technique was interesting.
    Last edited by R.Bolte.Jr; 12-15-2016, 12:12 AM.
    "Never bring a caliper to a mic fight"

  • #2
    That's some really Gold level info there. Thanks for posting the link.


    • #3
      Very clever technique, thanks for posting.
      The length for the vials made, 12.5mm is probably wrong; guess it should be 125mm (about 5").


      • #4
        I made my "machinists level" using that technique, and was quite impressed how well it worked. I tried used valve grinding compound and also rock polishing grit with a bit of water. The valve grinding grit was pretty pretty aggressive.
        I put a strip of adhesive weatherstripping foam on a paint stir stick to spin the glass tube - worked great!
        From memory, my vial is about 6 inches long. I punch cut some plugs from a silicon bumpers I'd made for another project (RTV in a cup), and poked them in the ends, filled the tube with alcohol and a bit of food coloring. I ground/cut/filed a window into a piece of 1/2" EMT and slid the glass tube in with a bit of tape wrapped around the ends for a light press fit. I adjusted the bubble size with a hypodermic needle and syringe. I made steel end caps that pressed into the EMT, cross drilled for calibration screws and jam nuts mounted it on a 1x1x8" piece of aluminum. The original vial lost some of the alcohol and I broke it trying to push it out of the EMT carrier (of course cut my thumb in the process). I suspect the coarse valve grinding compound left stress risers in the glass, so when I made a replacement I did more grinding with finer rock polishing grits.

        Adjusted the vial to level by swapping end for end to find true level orientation on my table saw top, "calibrated" with a couple different shims under one end and a sharpie marker to tick the vial (since rubbed off, but not actually needed for my purposes)

        If I recall, a .001 shim under one end moved the bubble well over an inch from center. Symmetry and repeatability (back to center) was very good. Plenty accurate for leveling a lathe, and cost me nothing but an hour or so of fun. I did notice recently that the bubble has grown again over the past couple years... I should use something better for the end seals.

        I'd post a picture, but it's 15F outside right now and about 50 yards through the snow to the shop...
        Last edited by Bellingahmster; 12-15-2016, 10:31 AM.


        • #5
          The bent glass technique probably works about as well as that, and is far simpler, although that technique IS closer to the "approved" method. For a shorter vial, the grinding method is likely better and more controllable.

          Neither that nor the bent glass is likely to produce a true curve form that can be accurately calibrated, but if the goal is simply to find "level", either would work as well, and I bet you would be hard put to it to find the errors even for calibrations.

          It's fashionable for "real machinists" to say the bent glass is useless, but that is obviously not true for simply finding the level position unless the glass is really bumpy on the inside. It would have to do with the accuracy of the marks as far as indicating specific slope errors off level.

          I expect that "real machinists" would have the same thing to say about the grinding method described.

          I'd bet that the same method would work fine with a shorter section of tube. I'm not sure why they needed such a long one, unless the optics for the artificial horizon viewer require it.

          I bet you also could happily melt-seal the ends. You'd do one end after grinding, drawing out the other, but not sealing, then filling to a mark to get the right bubble size, and melting the end shut with the bubble up. You'd want a fairly blunt draw-out on the filling end.

          heat should not distort it so long as you do not heat anything but the end, and you use a hot enough flame to get done quickly Glass is not a very good heat conductor.
          Last edited by J Tiers; 12-15-2016, 11:19 AM.

          Keep eye on ball.
          Hashim Khan


          • #6
            Sorry guys, I'm sure making a vial yourself is very gratifying and a great learning experience I just can't imagine it's cheaper than buying one.



            • #7

              What's their minimum order? I looked but did not see it. Maybe you have to open a "cart" to see.

              Keep eye on ball.
              Hashim Khan


              • #8
                Yes, he probably meant 12.5cm. That works out to about 12 lengths from the five foot tube so figure some waste when the glass company cut it into three pieces. He should have asked them to cut it into 12.5cm pieces.

                That is a very interesting technique and I see no reason why it would not work with a fair degree of accuracy.

                Originally posted by rodelu View Post
                Very clever technique, thanks for posting.
                The length for the vials made, 12.5mm is probably wrong; guess it should be 125mm (about 5").
                Paul A.

                Make it fit.
                You can't win and there is a penalty for trying!


                • #9
                  Shouldn't that be "never bring a feather duster to a handbag fight boys." Alistair
                  Please excuse my typing as I have a form of parkinsons disease


                  • #10
                    I have to agree, at that price and for items that sensitive it's sure not worth bothering to make our own.

                    I really have to wonder at the graduations too. On the first one in the table rated at .01mm/m each line is .01mm over a METER? That's likely more sensitive than many of us would need.... or would want for that matter. There's level and then there's "OCD to the MAX"....

                    I've always felt that level by my carpenter's level is close enough. After that I use DTI's to tram or check alignment with test cuts. After all "level" is only one way of lining up a machine. And really the test cuts or tramming is still needed to be sure.

                    But a sensitive vial for that much would be a really neat excuse to build a precision level even if it's just a further excuse to make a nice felt lined hardwood box to put it into and show it off.


                    • #11
                      Thanks for the post, since it was for me (I hijacked my own fly-cutting thread after all)

                      This is definitely interesting. I have almost all the material here to accomplish it on hand, except for the eye bolts for the jig. Very clever.

                      I think I'll consider this for a backup if the bending fails me.


                      • #12
                        Here's a link to the photos:


                        • #13
                          For the UK members (or others) there's a guy selling off a bunch of precision vials here:


                          I have bought five 20 second vials myself in very sturdy mounts. These could be useful for any number of applications.
                          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


                          • #14
                            To those wondering, I received an email back from Level Developments and their minimum order is $80. You'd have to buy a few vials.


                            • #15
                              I haven't had time to see the video so I hope no duplication, but the idea I have was a plug with small O rings to seal the ends with a small setscrew in the end to be a filling port, with sealer of course.
                              mark costello-Low speed steel