HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 16, 2002, 01:59 AM
Registered User
gbruce's Avatar
Canada, AB, Airdrie
Joined Oct 2001
2,324 Posts
Center of Gravity check ...please

I'm not sure if it's Dan or Daren, but I would really like one of those wonderful CofG checks superimposed on my bug as it has a little different wing than Kevins plans call for.

Thanks for your help!

I have checked it out for myself but would like a second opinion as the Test glides last year MAY have been done with the CofG a little to far aft, Pitched up and stalled twice..
gbruce is offline Find More Posts by gbruce
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 16, 2002, 11:51 AM
Registered User
Doc Watson's Avatar
UK
Joined Mar 2000
1,197 Posts
10%MAC and 20% MAC along with the MAC shown

Its up to you where it goes, suggest 15% MAC to start

Doc
Doc Watson is offline Find More Posts by Doc Watson
Reply With Quote
Old Dec 16, 2002, 12:22 PM
Ain't Dutch? Ain't Mutch!
Kimble_Schmitz's Avatar
Southampton, UK
Joined Oct 2001
3,384 Posts
Teach me please!

Need to know how you do this on curved wings using autocad.

I thought 23% MAC is normal, isn't it? Does this differ between planes? How about flying wings?

Please look in the Sniper thread and calculate the CofG of my E-vox flying wing, thank you.

Kimble_Schmitz is offline Find More Posts by Kimble_Schmitz
Reply With Quote
Old Dec 16, 2002, 08:16 PM
Registered User
gbruce's Avatar
Canada, AB, Airdrie
Joined Oct 2001
2,324 Posts
Thanks for the time you put in Doc.

A few Questions:

Doesn't the LEX effect this calculation at all??

I was thinking 23% like Kimble which basically put it where your NP is shown.

I am ,however, open to an education as far as the 10-15% that you are quoting

Thanks again.
gbruce is offline Find More Posts by gbruce
Reply With Quote
Old Dec 16, 2002, 08:42 PM
EDF Jet Jam 2015 , May 28-31
Kevin Cox's Avatar
St. Louis Intl, Missouri, United States
Joined Jan 1997
6,899 Posts
Bruce,

Yes the LEX does change it a bit. If you do the calculation without it it will come up tail heavy. 17% sounds about right but I suggest that you use the image you posted and make a glider. This is how the KC Bug CG was determind and I will do it for my Super Bug too.

Good luck!
Kevin Cox is offline Find More Posts by Kevin Cox
Reply With Quote
Old Dec 16, 2002, 09:08 PM
Registered User
Joined Sep 2002
7,938 Posts
He's right, it sure worked for my F-104.
Steve
U812 is offline Find More Posts by U812
Reply With Quote
Old Dec 16, 2002, 09:56 PM
Registered User
Daren's Avatar
Los Alamos, NM, USofA
Joined Nov 2000
3,123 Posts
Re: Center of Gravity check ...please

Quote:
Originally posted by gbruce
I'm not sure if it's Dan or Daren, but I would really like one of those wonderful CofG checks superimposed on my bug as it has a little different wing than Kevins plans call for.
Here's a quickie CG at 25%. Sorry I can't write more just now; holidays and all.

Daren
Daren is offline Find More Posts by Daren
Reply With Quote
Old Dec 16, 2002, 10:12 PM
Registered User
gbruce's Avatar
Canada, AB, Airdrie
Joined Oct 2001
2,324 Posts
You guys are really helpful!! Thanks!!

I pretty much have decided to start at 15% and go from there. I'll let you all know what happens if the weather doesn't go sour on me. Bungee launch emminent...

gbruce is offline Find More Posts by gbruce
Reply With Quote
Reply


Thread Tools