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-   -   Wing Loading and Cubic Wing Loading (https://www.rcuniverse.com/forum/gas-engines-142/4865058-wing-loading-cubic-wing-loading.html)

3d-aholic 10-13-2006 08:43 PM

Wing Loading and Cubic Wing Loading
 
What is an acceptable wing loading for flying good 3D on a 27-28% plane?

Is a wing loading of 30.45 oz/in or a cubic loading of 9.76 oz/cu. ft. ok?

AirWizard 10-13-2006 08:56 PM

RE: Wing Loading and Cubic Wing Loading
 
IMO 23 to 25 oz/in

3d-aholic 10-13-2006 09:01 PM

RE: Wing Loading and Cubic Wing Loading
 
Can't be...[X(]
Using this site here...http://adamone.rchomepage.com/design.htm

A EF YAK with a DA50 at around 1400sq and 15.5lbs...is 25.51oz/sq ft. and is that about one of the absolute best case scenarios...yet its already slightly past your highest range.

Tired Old Man 10-13-2006 10:10 PM

RE: Wing Loading and Cubic Wing Loading
 
Cubic loading unneccesarily complicates the computation. Your plane would fly well at 34 oz/sq. ft. depending on available power. More power makes 3D possible. Average power means standard aerobatics would be the area flown.

3d-aholic 10-13-2006 10:20 PM

RE: Wing Loading and Cubic Wing Loading
 


ORIGINAL: Silversurfer
Your plane would fly well at 34 oz/sq. ft. depending on available power. More power makes 3D possible.
Well it would be a 58cc on a 28% so I think there would be plenty of power....thats why I'm trying to determine if the combination works and how far I'm into the "lead sled" arena.

rmh 10-13-2006 10:28 PM

RE: Wing Loading and Cubic Wing Loading
 
for really good 3D that size is better at 25 -- My own EF YAK weighed 15.25 with piped ZDZ50 -turning Mejzlic 22x8 at 7750 static
instant acceleration and super slow falling maneuvers
lots o power and min weight is the 3D formula- no way around it
but -- my 39 lb pig of a 42% at 2600 squares -is 34 lb loading and is also a "feather " relatively. just not the acceleration of the YAK
My EDGE at 23 lbs and 1650- is close to 33+-- not as good at slow 3D but still very good at power maneuvers. Lots o power.
30 - is a decent number for most stuf -in THAT size ---- but lower is better -
now go to really good electric flat foamies - the power to weight is far far better and the performance is like a hummingbird
wing loadings of 3-4 ounces per sq ft.

AirWizard 10-13-2006 11:16 PM

RE: Wing Loading and Cubic Wing Loading
 
AirWild Extra 260 has a 24.8 oz/in

Flip and Fly 10-14-2006 03:54 AM

RE: Wing Loading and Cubic Wing Loading
 
Don't forget that there is a scale effect, the more wing area "over all" the higher that number can go I think.

Like on a 28% I would go no higher than 30 oz/in. ( depending on your location, altitude, air temp) for good 3d.

On a 35% you can go to about 32 oz/in and have the same result as the 28% on 30 oz/in.

On a 40% you can go to about 34 oz/in and it will fly like a 28% at 30 oz/in.

Or so it seems to me.

Also altitude were you fly, and temperature, will have an effect on lift.

Cooler air = more lift

Denser air = more lift :D

rc bugman 10-14-2006 06:59 AM

RE: Wing Loading and Cubic Wing Loading
 
Hi,

If you want to "design" planes of different sizes to fly similar, you need to use the cubic loading formula for comparison. Simple oz/sq ft calculations are not represensitive. thus the saying "larger planes fly better" For example, a 25% cap with a wing loading of 25 oz/sq ft will fly the same as a 33% cap with 32 oz/sq ft, etc. (these are just figures to illustrate the concept, not actual calculations)


Elson

Flip and Fly 10-14-2006 08:24 AM

RE: Wing Loading and Cubic Wing Loading
 
I agree, its what I was saying. Without having to get into all the formulas it was just worth noting that.

By the way what is the formula.

Thanks.

3d-aholic 10-14-2006 09:51 AM

RE: Wing Loading and Cubic Wing Loading
 
Yes, cubic loading is suppose to be something you can compare across plane sizes. For example, a EF Yak87 at 5.5lbs would be a cubic loading of 8.18. I'm suggesting a cubic loading between 9.24 (best case) and 9.76 (worst case).

[link=http://adamone.rchomepage.com/design.htm]Heres the formula.[/link]

Flip and Fly 10-14-2006 10:04 AM

RE: Wing Loading and Cubic Wing Loading
 
Thanks, that is well illustrated.

Flip and Fly 10-14-2006 10:49 AM

RE: Wing Loading and Cubic Wing Loading
 
I used the cubic loading program to see what I get with my 3D planes.

1/4 Extra is 28.8 oz/sq ft wing loading.
Cubic loading for that one is 10.33.

In the real world it flies light, good 3D!


35% Ultimate is also 28.8% wing loading.
Cubic loading for that one is 7.58.

In the real world it flies very light too, good 3D. I find it just a little better than the little extra, but then its a bipe, two wings seem to get less lift that one big one over all.

35% Extra with a whopping 34.21 oz/sq ft wing loading.
Cubic loading for that is 9.81! Hmmm, less than the little Extra, even with a much higher wing loading.

In the real world it flies as light as the little extra, soooo I can verify from my experience that its all rather accurate.

3d-aholic 10-14-2006 11:27 AM

RE: Wing Loading and Cubic Wing Loading
 
Ok great...yes...hard to tell if those numbers mean anything in the real world...and you have 2 out of 3 that are above the cubic wing loading I suggest so perhaps its doable then.

Flip and Fly 10-14-2006 11:33 AM

RE: Wing Loading and Cubic Wing Loading
 
Looks to me like anything with a 10 Cubic wing loading, or close to it will 3D.

And I know how to 3D, I am talking slow 3D, rolling harriers, harriers, high alfa knife edge, avalanches, flat spins, all that cool stuff :)


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