HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 11, 2012, 10:30 AM
Registered User
ian murdock's Avatar
United States, NV, Carson City
Joined Jan 2007
631 Posts
Help!
CG help

Hi guys, what is the percentage of cord length that is CG for a RG14 airfoil?
ian murdock is offline Find More Posts by ian murdock
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 11, 2012, 10:35 AM
Just fly it!
wyowindworks's Avatar
Cody, WY
Joined Nov 2007
6,915 Posts
The airfoil doesn't really determine the CG but rather the configuration of the entire aircraft. Most mortals like the CG to be on or ahead of the neutral point for the plane.

You can use this utility to get a really good start. I use a static margin of 7-9% for the first go.

http://adamone.rchomepage.com/cg_calc.htm
wyowindworks is online now Find More Posts by wyowindworks
Last edited by wyowindworks; Oct 11, 2012 at 10:40 AM.
Reply With Quote
Old Oct 11, 2012, 10:36 AM
Embrace the suck
nauga's Avatar
Joined Nov 2004
4,269 Posts
Quote:
Originally Posted by ian murdock View Post
Hi guys, what is the percentage of cord length that is CG for a RG14 airfoil?
Depends far more on tail size and arm than airfoil. Is this for your Hawk? If so, 25-30% is probably a reasonable range, maybe a little closer to 25 than 30. Can you give us an idea of the overall planform?

edit: or just follow Adam's advice

Nauga,
and his Cm-alpha curve
nauga is offline Find More Posts by nauga
Reply With Quote
Old Oct 11, 2012, 10:53 AM
Ninja Master
BigSwede's Avatar
United States, CA, Thousand Oaks
Joined Feb 2007
1,770 Posts
The CG calculator that Adam posted works great.
BigSwede is online now Find More Posts by BigSwede
Reply With Quote
Old Oct 11, 2012, 11:45 AM
Registered User
ian murdock's Avatar
United States, NV, Carson City
Joined Jan 2007
631 Posts
Thanks guys for the help, the cg is on my FW TA-152. I'm going to try the Cg calculator on my phone. the reason why is because I don't have enter net down at my shop anymore.
ian murdock is offline Find More Posts by ian murdock
Reply With Quote
Old Oct 11, 2012, 12:38 PM
Ninja Master
BigSwede's Avatar
United States, CA, Thousand Oaks
Joined Feb 2007
1,770 Posts
CG calculator works great on my iPhone.
BigSwede is online now Find More Posts by BigSwede
Reply With Quote
Old Oct 11, 2012, 02:35 PM
Registered User
ian murdock's Avatar
United States, NV, Carson City
Joined Jan 2007
631 Posts
It all worked out, i used my phone and was able to get the CG spot on. Thanks again guys. Now i just need to find the time to test fly.
ian murdock is offline Find More Posts by ian murdock
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Please Help : Graupner grob G 103 twin acro CG j.m.costa Flying Wings 0 Sep 11, 2012 10:16 AM
Help! CG Help Nicksbbq Parkflyers 5 Aug 19, 2012 10:07 PM
Help! CG Help Nicksbbq Sport Planes 0 Aug 18, 2012 09:41 PM
Question please help id wing and cg (cg found) steeg Slope 3 May 07, 2012 09:46 PM
Help! Cg help!!!!! Help me!!!!!!!!!! cale10 Electric Plane Talk 8 Mar 30, 2012 07:48 PM