This is the beta version and first public release of this RC design spread sheet.

http://www.angelfire.com/scifi2/wiza...aft_Design.zip

It is divided into 4 separate pages:
1. Gliders
2. Power
3. Canards
4. Flying Wings

The basis for this spread sheet comes from a CG program that published in “Soar Tech” (don’t remember the issue). Plus information from a number of other various sources. It started out mainly as a CG calculator and has expanded to calculate other basic parameters. Such as Tail Volume Coefficients, MAC, static margin, Aerodynamic Center, also it give a conversion from a standard tail configuration to a V-Tail.

To use the sheet fill in the gray areas with the aircraft’s data (all units are in inches). The yellow fields will reflect the calculations based on that data. While the blue fields will then show the suggested minimums, (NOTE: this data is presented for comparison purposes only.)

Suggestions and constructive criticisms are always welcome.

Alan Sinclair
[email protected]

Ha Alan. Thanks for the spread sheet. This will come in very handy.
Thanks agin..

Dave G

Looks good, can't wait to put it to use.

Don

Can the c.g. for the flying wing be changed?
And what is it right now?

hi Alan cant access your web page......can you help me....or e-mail me your program...thanks Glidaguy

for the flying wing change the areas in gray with your data and it should do the rest.

If not let me know and I'll fix it.

I have gone over my bandwidth limit today.

I've attached it.

Alan
[email protected]

Well, there's a typo in the Area heading in the grey area also.
Easy fix.
It does look like a good tool. The numbers I've worked so far agree with other sources.
I do like to know what the c.g. the sheets use, in case I want to change it.
Usually I set in a straight wing of 10" chord and see what the c.g. computes to, but it's a nicety to see where square one is.

Tall Paul

Sorry, I guess I’m not understanding the question, “… what the c.g. the sheets use, …” Is this referring to the formula?

I’ll can to dig up where I got the data from. I have had this spread sheet sitting around for awhile and the memory is a bit fuzzy.

Alan

I think he wants to know what the CG percentage is so if he wanted to change the parameter, which cell would he have to go into to change it.

Your spreadsheet has a set CG point calculated by the formulas, which cell would he have to change to move the CG forward or back from the point calculated now?

That about right, Tall Paul?

I could be out to lunch
Don

Hi Alan, great tool....thanks very much!

Question: I'm working with a friend on his variable CG canard project (Don't ask! ) and am wondering if your program will compute the CG for a canard just by entering negative numbers into the "Distance from leading edge wing to leading edge tailplane and Distance from AC of wing to AC of stab" fields, if not, how?

thanks Wizard...glidaguy

.
Close... I like to know what the fixed values are in addition to which of them are variable.
The c.g. in the "wing" section is 18%.
12.3% (negative) for the "canard" section..
40% in the "power" section
and 37% in "glider"..
but apparently the option to change isn't part of the sheet.
I'd prefer that option.

Oops, sorry Alan....I failed to heed Paul's favorite warning: "RTFB." I read your instructions and saw that you have canards covered.

Thanks again for a great little program!

Tall Paul

I'll dig up the reference material and my notes this week end and let you know.

Have a great day.

Alan

Tall Paul

Here are the equations that are used to calculate the CG for the flying wing. They were derived from equations published originally by Ron Van Putte, June1980, Model Aviation and then they were used in a Basic program printed in Soar Tech.

CG = P + ACw

P = (R^2 + (R X T) + T^2)/(15(T + R))

R = Wing Root Chord
T = Wing Tip Chord

The CG in % MACw is calculated for each combination of variables.

I hope this helps.

Alan

Thanks... it calculates where the c.g. should be...

Hey! This is what I've been looking for, although I don't understand all the terms.

Will you please give a hand? I'd like to know what they mean or if there is a link where I can find more info.

Here I go:

1. Leading edge sweep offset (LESO): I thought that Root_chord = Tip_chord + LESO but I'm wrong...

2. Static margin?

3. P?

4. DIH angle and the related in this frame (wing loc. etc.)

Thanks in advance.

Here you go.

1. Leading edge sweep offset (LESO): I thought that Root_chord = Tip_chord + LESO but I'm wrong...
The leading edge sweep offset is the distance from the leading edge of the root chord to the leading edge of the tip chord. Check out the article by Ron Van Putte, June1980, Model Aviation. It has all the equations.

http://www.angelfire.com/scifi2/wiza...es/Canards.zip

2. Static margin? Here is a very good definition of what the Static margin is. Better than I could by a long shot.

http://www.moneysmith.net/Soaring/soaring8.html

3. P? This is a multiplier derived from this equation also from the article above.

P = (R^2 + (R X T) + T^2)/(15(T + R))

I am not aware that it has a name.

4. DIH angle and the related in this frame (wing loc. etc.)

This is the dihedral angle of each wing panel from the horizontal.

Hope this helps. If not let me know.

Have a great day.

Alan

Where I cabn get this article? Is there any online source? Maybe someone can scan it and email it?

I'm from a third country world and don't think our library could have some copy.

Thanks in advance.

Lee Van Tassle did an Excel design Spreadsheet several years ago. I recall it also included canards. It can be located at this URL
http://www.cncfoamfactory.com/tech.htm

You guys need to make sure you aren't re-inventing the wheel.

It at the link I posted above.

http://www.angelfire.com/scifi2/wiza...es/Canards.zip

If it doesn't work let me know.

Alan