Centre of gravity calculation
 

Could someone be good enough to check the CG calculation as per the sketch below.

Tapered wing with straight trailing edge.
Root chord 450mm
Tip chord 250mm
Mean chord = 350mm
25% Cg = 25% of 350 =87.5 mm plus distance from mean chord to leading edge = 100 =187.5mm behind leading edge?

Thanks you mathematicians!

John Agnew

RE: Centre of gravity calculation
 

Need the length of one of the wing panels.

RE: Centre of gravity calculation
 

tail volume and fuselage shape are also key variables too...

RE: Centre of gravity calculation
 

Wing panel is 950 mm long.Tailplane size is 600 long x 180 wide.

John Agnew

RE: Centre of gravity calculation
 

John;

You are good to go as calculated.

RE: Centre of gravity calculation
 

Kenny and others

Many thanks for your help!

John Agnew

RE: Centre of gravity calculation
 

and what is the distance of the tail plane from the trailing edge of the wing? this airplane has a long nose and/or flat areas in the fuselage aft area? how much sweeptback has the tailplane?
sorry, but I cant´figure out a aproximate cg value without this info.

RE: Centre of gravity calculation
 

Here ya go...

http://www.geistware.com/rcmodeling/cg_calc.htm

Dave Rigotti

RE: Centre of gravity calculation
 

Dave

Thanks for that. My calculation seems OK.

John

RE: Centre of gravity calculation
 

I agree. Looks like 180-195mm back will be fine. Maybe more depending on how radical you want it to fly. Me? I aim towards the front. Flick rolls ain't my thing!

Dave Rigotti

RE: Centre of gravity calculation
 

Dave

I will be interested to hear Allan's comments on thr CG issue with the Intro. He was quite firm about the 150mm position for first flights as are the instructions.

Maybe he likes a nose heavy model?

No chance of flying mine this week. After some nice flying weather in Jan / Feb we are now having the coldest weathe of the winter.

On another issue I see you are waiting for a Savex L39. I have the Schreiner version which is very similiar. I believe the two guys used to be partners. I only waited about 8 weeks for mine and it flies well. Blame the popularity of the Savex version on the thread!

Axel Schreiner also does a F18 which is the same size as the old Yellow single engine job.

John