Cg issues
 

Well I made the mistake of buying a less than reputable brand warbird for my first build, so the already shotty Manuel didn’t come with a cg location. Not knowing the proper cg point, I improvised by looking at a different brand, but same size and identical model, cg point. Well what’s really odd is it takes about 10oz of counter weight at the very rear of the plane to get the correct "hypothesized” cg. I was just wondering if that much weight is just insane since it seems to me adding quite a bit of weight to the plane. Oh and this plane is and fu4 corsair .50 size being powered by an evo 1.00 nx, this is the airframe I bought http://www.nitroplanes.com/f4ucorsair5055.html .

RE: Cg issues
 

G'day Mate,
Are you sure it didn't have a CG (balance point) in the manual, it should be towards the end of the manual, possibly inside the back page, it may be in the same section that shows control throws.
If that is the CMPro ARF, 58" span, the CG (balance point) is 80 to 85mm back from the leading edge of the wing. I have put 5 CMPro ARF's together, & they always have the CG, or balance point in the manual, somewhere.
If it the other one, 55" span, whatever brand it is, I'm still betting it is in the manual somewhere.
If you can't find it, use this calculator, to help with your CG, keep it in your favourites, it may be useful later on.
http://www.palosrc.com/instructors/cg.htm

RE: Cg issues
 

I would speculate that the reason you have to add 10 oz. of weight to the tail is because of the engine you are using. Seems to me that an evo 1.00 engine is way too much for a '.50' sized plane. I would think that a .60 would be plenty. Remember, lighter usually flies better (especially with warbirds!).

RE: Cg issues
 

G'day Mate,
It's OK, he shouldn't be flying it for a looong time.
BTW, Koala's aren't bears. they are Koala's.

RE: Cg issues
 

It's a quote.[8D]

RE: Cg issues
 

If it's the Nitromodels Corsair 50 the Cg should be 80 to 85mm back from the Leading edge at the fuse.

Look at you manual again:

RE: Cg issues
 

If you have other questions they have a support forum here on RCU.

http://www.rcuniverse.com/forum/forumid_456/tt.htm

Like every other company they have some problems but they appear to be trying.

BTW 80 mm= 3.1496062992125986 inch and 85 mm=3.3464566929133856 inch

RE: Cg issues
 

Wow, can we measure that with a tape?

RE: Cg issues
 

I just provide the numbers. Accuracy is up to you.:D

RE: Cg issues
 

Bruce i just wanted to thank you for your help, the info you gave me really got me out of a bind.

RE: Cg issues
 

hi, thanks for helping me with the cg issue, the measurments you gave me saved me alot of frustration. Well again i cant thank you enough lol.

RE: Cg issues
 

Now do i measure 3.24 inches from the leading edge at the wing tip, where the wing is thinnest, or do I measure 3.24 inches from the leading edge near the fuselage where the wing is thickest.

RE: Cg issues
 

Minn found the drawing. I just crunched the numbers. Me and Google that is.:D

RE: Cg issues
 

Now why are CMP kits "Less than reputable"?

The manuals stink, but anyone purchasing CMP/KMP or other asian kits should be aware of this.

RE: Cg issues
 

it wasnt a cmp kit, it was a evergreen kit. I actually regret not buying a cmp kit.

RE: Cg issues
 

Measure distance back from the front (leading edge) of the wing right next to the fuselage of the plane. NOT at the wing tip. Some planes are measured at the tips and that will be called out in the manual if it is the case.

RE: Cg issues
 

lol i just realized the original link i had wasnt working rite, was the number you gave me for the cg for a evergreen or cmp f4u. < i have the evergreen, if u want to look at it i corrected the link issue.

RE: Cg issues
 

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RE: Cg issues
 

Ok, DO NOT use that dimension, that is for the CMP model.

However, yours is only 3" shorter in the wingspan, so it will be close to that anyway.

I would give an educated guess and say that if you balance it in the 75 - 80mm range it should fly well enough for you to decide from there if you want to change it.

RE: Cg issues
 

Recheck your manual or post on the support forum.