please tell me what the c of g should b for my 28%xtra 300l
03-25-2008, 09:12 PM
#1
Senior Member
Thread Starter
Join Date: Aug 2007
Location: christchurch, NEW ZEALAND
Posts: 619
Likes: 0
Received 0 Likes
on
0 Posts
please tell me what the c of g should b for my 28%xtra 300l
Hi
I have just purchased the above plane & am unsure were to start with the c of g, any help would be really appreciated.
if it helps, she has a glass fus & foam vernered wings bgx1 up front with carbon bolly pipe
John
new zealand
I have just purchased the above plane & am unsure were to start with the c of g, any help would be really appreciated.
if it helps, she has a glass fus & foam vernered wings bgx1 up front with carbon bolly pipe
John
new zealand
03-26-2008, 08:33 PM
#3
Senior Member
My Feedback: (10)
Join Date: Jul 2005
Location: Christchurch, , NEW ZEALAND
Posts: 436
Likes: 0
Received 0 Likes
on
0 Posts
RE: please tell me what the c of g should b for my 28%xtra 300l
I still have the plans for a Midwest Extra 300 if that's of any help 
John. It's a 27% jobbie but
CFN, Paul
John. It's a 27% jobbie butCFN, Paul
03-26-2008, 11:56 PM
#4
Senior Member
My Feedback: (1)
Join Date: Sep 2003
Location: surrey,
BC, CANADA
Posts: 3,775
Likes: 0
Received 0 Likes
on
0 Posts
RE: please tell me what the c of g should b for my 28%xtra 300l
I think the Midwest was at 6 inches or close to the spar,but with sheeted foam wings it aint gonna help much.
03-27-2008, 03:51 AM
#5
Senior Member
My Feedback: (40)
Join Date: Dec 2001
Location: Merrimack,
NH
Posts: 1,597
Likes: 0
Received 0 Likes
on
0 Posts
RE: please tell me what the c of g should b for my 28%xtra 300l
Check out http://www.airfieldmodels.com/inform...amic_chord.htm
There are a bunch of CG calculators on the web, just google "mean aerodynamic chord" and you'll find them. At least one has an on-line calculator into which you enter data for the parameters Pat Roy is asking for, and it spits out the answer for you. I'd give you more links, but they're on my other computer.
I normally set my aerobatic models at 30% of mean aerodynamic chord for the first flight CG, then adjust from there. This is a pretty safe setting, without being so noseheavy as the 25% that is commonly recommended by legal departments of model manufacturers.
There are a bunch of CG calculators on the web, just google "mean aerodynamic chord" and you'll find them. At least one has an on-line calculator into which you enter data for the parameters Pat Roy is asking for, and it spits out the answer for you. I'd give you more links, but they're on my other computer.
I normally set my aerobatic models at 30% of mean aerodynamic chord for the first flight CG, then adjust from there. This is a pretty safe setting, without being so noseheavy as the 25% that is commonly recommended by legal departments of model manufacturers.
