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Calculating wing area of model airplanes (Read 2893 times)
Reply #3 - Sep 20th, 2012 at 11:57pm

Sky9pilot   Offline
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Stick & Tissue
Kelso, WA 98626 USA

Posts: 11068
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Great stuff guys...I guess I'm just lazy.  I just have to plug in numbers into the calculator for my way!!!

But an elipitical wing (Spitfire) etc. I can see your systems working easier for this lazy guy.  Plus remember, math is not really my thing.

But I'm growing in this area Smiley Grin Wink Cool

Thanks guys for these alternative methods, can never get too many options to choose from.

Tom
 

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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Reply #2 - Sep 20th, 2012 at 11:28pm

Ates   Offline

Stick & Tissue
Los Gatos, CA

Posts: 25
 
A fairly accurate method, essentially similar to Eric's:

Cut a rectangular piece of cardboard which is larger than the wing section you want to measure. The wing section should be able to completely fit in the rectangle. To simplify the math you may want to oversize the rectangle such that both the length and width are multiples of exact inches. Weigh that piece of cardboard. Also record the area as L*W.

Now trace the wing outline onto the same piece of cardboard and cut it out. Weigh the cutout (which has the same shape as the wing section). The ratio of the weight of the cutout to the weight of the complete rectangle is the same as the ratio of the area of the wing section to the area of the rectangle. Or:

(Area of the Wing Section) = (Area of the Rectangle) * (Weight of the Cutout) / (Weight of the Rectangle) 

Best,

--Ates
 
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Reply #1 - Sep 20th, 2012 at 8:47am

thymekiller   Offline
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Missouri

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Excellent site. Tons of info and pics. A VERY GOOD site!!!
Thanks Tom!!!

I have another way to calculate wing area, altho I am sure it's not as accurate.  Much less math, but you need scales.

Cut a piece of thin cardboard exactly 1 inch x 1 inch.
Weigh it. 

Trace the outline of your wing onto the same cardboard and cut it out.
Weigh it. Divide that by the number that you got for 1 square inch of cardboard.

Poster board works well also.

For example,:
If one square inch weighs 1 gram...
If the outline of your wing weighs 16 grams...
you would divide 1 gram [the square inch] into 16 grams [the wing outline] and you get 16 square inches of wing area.

Exaggerated numbers, I know, but you get the point.

To further this, if you want to know if your plane is "heavy"'
Divide your planes wing area in half and that will tell you how many grams it should weigh.
The above example should have an "all up" weight of 8 grams.

Most of mine are "heavy". Embarrassed Embarrassed Grin Cool  The half a gram per square inch thing is NOT cast in stone. Alot depends on other factors, like wing design, frontal area, drag, indoor or outdoor, ect. But it will get you in the ball park for rubber free flight. I have had planes at 6.5 grams fly outside, and some peoples indoor planes come in around 4 grams or less.

Weight and wing area are a great topic for discussion.
Does anybody have any thoughts on the subject?
 

",,,The road goes on forever, and the party never ends..."
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Sep 14th, 2012 at 1:54pm

Sky9pilot   Offline
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Stick & Tissue
Kelso, WA 98626 USA

Posts: 11068
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Found this site for calculating wing area of straight wing, tapered wing, delta wing aircraft.  This was very helpful to me.

Airfield Models site: http://airfieldmodels.com/information_source/math_and_science_of_model_aircraft/...

There's a lot of other great stuff on the site so you may want to...
Check it out... Smiley Grin Wink Cool

Tom
 

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
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