Pushed by the need for a precision level, after having failed to make an electronic sensor, I wondered if it was possible to exploit a sample perfume vial to make a machinist level. You will see in the video.
Greetings to everybody.
Thanks Claudio, for yet another creative approach, nicely looking and well executed tool (and video)!
I've been walking this tedious road myself for quite a while now,
as the tiny nib of the vial of my cheapo Machinist's Level broke when overhauling it, described in this dismal read:
35 buck Chinese Machinist's Level overhaul and cralibation (!)
I've still some work to do on that project:
1) Refill the vial with the appropriate amount of the proper fluid.
2) Permanently seal the vial (easier said than done).
3) Reliably and sustainably fix it in the housing tube.
4) Remount in and calibrate the level.
A few findings of mine so far (FWIW):
The original fluid in these high precision vials is "Ether" (Diethyl Ether or Ethoxyethane) and that for a darned good reason:
Low kinematic viscosity, i. e. it flows really easy in the vial of such a low curvature,
as to get a 2 hundreds of a mm (per div) in 1 meter.
Even with this very low viscosity fluid, the bubble still would take some 20 secs to set...
But depending what kind of resolution you aim for, other fluids (like acetaldehyde, ammonia or acetone) might be good enuff...
Snag with Ether is the volatility and vapor pressure at room temp, making it hard to handle (aside of even getting hold of it).
Next assignment is to get the fluid into and keeping it permanently within the vial, as in the above steps 1 & 2...
My experience is that ether really effectively prevents epoxi (and everything else I've tried so far) from curing.
Next try will be adding a droplet of waterglass (Sodium Silicate) to the nib, instanty cured by a shot of CO2 gas.
If that is good enuff is to be determined - other suggestions welcome...
But that's to come in another post in the thread above.
Thanks Johan. About the fluid I've tested many fluids.
- Ethilene 90% + blue methilene (as dye): slow.
- Perfume (yes, the original perfume): quite good. I have no idea of the composition.
- Acetone 100%: excellent but it would eat up the seal in the long run,.
- Ethil-methilene 94% (ethilene+10% methilene, up to reach 94%): good enough.
For the seal I've used the original cap of the perfume vial.
About the bubble. I've noticed that the smaller the bubble the slowest the response. There is a physical explanation for this but I didn't digged much into it to check it out. So for a faster response let the bubble be generous as much as possible.
For the fluid my final choice was ethil-methilene. In short it is industrial "alcohol" with the classic pink dye.
Be careful to add a dye because it could change the viscosity of the fluid. In general aniline dyes, in very little amount, should not modify the viscosity. Blue methilene should be a good choice but I noticed that the one I bought is "already diluted" in water! That's probably why in my experiment the bubble moved so slow, I think.
An other point to keep in mind is the possible reaction of the vial's material with the fluid, i.e. if the fluid is polar. That should be not the case with glass, though.
About the seal. Sodium silicate should bond quite well with glass, but I have no experience.
Epoxy won't work at all. Not only you could experiment snags in making it to cure, but also it could even decompose in the long run. Also, epoxy in general requires almost 15°C to cure, if you put it in freezer it won't cure at all.
If the sodium silicate works to seal the nib, then epoxy could be used to externally keep in place and reinforce the sealing.
Last edited by Claudio HG; 08-09-2020 at 08:09 AM.
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