I have a cmp extra 300s 1.40 I need to balance. I heard I could take the plane and turn it up side down and pull out the wings a little bit and place 2 pieces of string around the wing tube on each side. Going by the measurements in the directions it seems that the center of gravity runs along the front edge of the tube. Is this close enough to to use the string method or should I get a get a cg machine? Thanks for any help,
Chad

Why don't you just put your fingers under the wing where you want to ballance it! Why waste the time or money on expensive tools for ballancing that won't work any better than your finger. [X(]

I tried, this plane is just too big. My fingers will brake through the wings.

try the following link,this is what i use,very simple to make. http://home.mindspring.com/~the-plum...%20Machine.htm

String is cheap. And accurate as heck.

But if your fingers would punch the wings because the sucker is so heavy, maybe you oughta use braided steel cable or light chain.

You're right about tying the cord to two different places on the model, but those places ought to be: decently forward and decently back. Most planes, the prop shaft and tail wheel work great. But you can use anything that lends itself to the task. I've used the "rubber band dowels" you find on trainers and other models, for example.

You do need to use an additional string. You need one with a plumb bob on the end of it to point to where the CG is. The CG will be directly below the bob, obviously. The bob should be hung from where the other string is hung.

hey bigdarylg,
That is one excellent article. Really covers the technique well.

Thanks, that is one cool article and easy to follow. You just same me a little money!!

anytime guys, i try to pass on good info as much as possible