Looking for best way to level airplane.

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Eugene

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Please add a little dish washing detergent into the water.
the soap will reduce the surface tension.
I did some more thinking about using of RV antifreeze. Maybe it's not a such a good idea after all. In my world of hydronic radiant heating every time we use an anti-freeze instead of water pump performance is deteriorating. Much easier to pump water. Maybe I should use little alcohol or soap, but no antifreeze.
 

Eugene

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Unfortunately the tubing volume changes with the amount of head since the plastic tube expands under slightly increased pressure. So if you mark a couple of lines when a foot off the floor, the water will no long reach the marks when 7 feet in the air.
Sure, maybe, but very little and both ends will be level to each other anyway. And this is what I am after.
 

Gregory Perkins

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I did some more thinking about using of RV antifreeze. Maybe it's not a such a good idea after all. In my world of hydronic radiant heating every time we use an anti-freeze instead of water pump performance is deteriorating. Much easier to pump water. Maybe I should use little alcohol or soap, but no antifreeze.
SOAP ? ABSOLUTELY NOT ! ! ! Soap increases chances of bubbles.

The reason why a 5 gal bucket works so well is you feed the tubing in one foot at a time and coil it up in the bottom of the bucket. This is the easiest way to fill the tubing without any bubbles. Every bubble you have can cause the reading to be off by about the internal diameter of the tube. Actually antifreeze is similar to alchohol ie glycol
so I dont see any reason why it would not work well. Just a little expensive however.
The alchohol ( or anything else water soluable that reduces surface tension ( surfactant)
makes the fluid in the tube move very freely without snaging and jumping around.
 

FinnFlyer

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I use a slightly different method. I only use one end of the tube for all my measurements. Take your clear tube and submerge many coils of it into a 5 gal bucket
of water treated with a quart of rubbing alchohol and a bottle of food coloring from grocery store. When you submerge the tubing go slow and eliminate all bubbles in the hose. Then take just one end of the tube out and walk as far as needed to measure
your target. What you will get at the end of the tube you are holding is a constant
level indication and you can mark that on your target or multiple targets. When done for the day just coil the tube back into the bucket and put the top on the bucket.
What I sometimes do is tape the end of the tube to one end of a yardstick. and then tape the rest of the tube to the length of the yardstick so you can use the measurements
on the yardstick for comparison to other measurements when holding the yardstick vertical. The name for this contraption is "The Egyptian Magician"
Be aware that you can't use that for day-to-day measurements (or even while a thunderstorm rolls though). In other words, the absolute level varies with air pressure.

Finn
 

Gregory Perkins

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Finn- unless you can define day to day measurements or absolute level you are
flat wrong. If you understand what the fluid in the tube is telling you, it will
NEVER lie and air pressure, barometric or altitude makes no difference what so ever.
The technique is not a device like a measuring tape, it is exclusively for comparisons
of the elevation of two or more points. All of them being more or less by how much
or equal .
 

Aerowerx

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Be aware that you can't use that for day-to-day measurements (or even while a thunderstorm rolls though). In other words, the absolute level varies with air pressure.

Finn
Uh no, water is non compressible. Air pressure will have no effect on the water level.
 

Rataplan

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You can get,for free,phone apps,that are super easy to use and very acurate.
Can test against whatever you have now,again
its free.
Lot of them are not accurate some are but depends also on your phone.
Yes, I do have a digital levels. Several of them. Also have laser as well. Where I get confused is when I level airplane from the front with laser and then I raise both wings to 1.5° dihedral - Wings looking in-line with laser level line, but struts don't measure the same with 3 mm difference.

I was already back home when I start thinking that wings possibly built differently and have different dimensions. I will check that next time.

View attachment 111810View attachment 111811
3.4 mm per m accuracy ... I think a gardenhose with two end tubes are more accurate
 

Rataplan

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If I recall correctly, a column of mercury is affected by air pressure…..:popcorn:
The airpressure will be the same on both ends , its only a few meters between the ends. LOL. to check just hold the two ends together and very easy to see if the levels are the same. Its all very static so pressure is all what does the work
 

dog

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Lot of them are not accurate some are but depends also on your phone.

3.4 mm per m accuracy ... I think a gardenhose with two end tubes are more accurate
You are right,its more the idea of bieng able use one level to check another,and if you are
like me then its also an oportunity to get rid of the stuff that is just junk.
Also when I have been stumpted needing more
accuracy than my tools and methods can deliver ,I have resorted to repeating my measurements many times,throwing out the
wild ones and averaging the rest,with good results.
 

FinnFlyer

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Uh no, water is non compressible. Air pressure will have no effect on the water level.
Seriously?!
Did you even read the post I was replying too??
"Take your clear tube and submerge many coils of it into a 5 gal bucket
of water ..."

You're telling me the laws of physics have changed and the level at the open end will not change as the ambient pressure changes?

Never mind. Don't see how Gregory's idea will work. A standard atmospheric pressure will support about 35' of water column, so unless you have a very deep basement to put the bucket in ... I doubt the alcohol will make that much of a difference.

Perhaps he omitted to mention taking the submerged end out of the bucket and fixing it at a suitable height?

Edit: Finally remembered that the water (or mercury) column is for a closed hose. In other words a vacuum at the high end.
Atmosphere pushing on the water (or mercury) in the bath (bucket), nothing pushing on it in the other (free) end of the hose.
Embarrassed. :oops:

Finn
 
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wsimpso1

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Eugene,

Please tell me you are not eyeballing that miniscus to the rounded top of the wing... The reason to object is you can raise or lower your point of view slightly to make a fair range of positions all "line up".

Use four fixtures cut and sanded to be identical, and now you have straight edges to align your ruler on for each check. If you are really going to work to any level of precision, you ought to have a fixture on top of the wings at root and tip. The fixture should reference nicely on some fixed point on the foil, like the leading edge.

Billski
 

Eugene

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Eugene,

Please tell me you are not eyeballing that miniscus to the rounded top of the wing... The reason to object is you can raise or lower your point of view slightly to make a fair range of positions all "line up".

Use four fixtures cut and sanded to be identical, and now you have straight edges to align your ruler on for each check. If you are really going to work to any level of precision, you ought to have a fixture on top of the wings at root and tip. The fixture should reference nicely on some fixed point on the foil, like the leading edge.

Billski
I simply didn't get time to accomplish this yet. Don't worry, I will do my best to get it right. I would like to see the pictures of how this kind of templates done by professionals. First I was trying to make water level working for me. Who would guess that this can be so complicated.
 
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