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Wildthing
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When I haven't a clue as to where the CG is on my unorthodox scratch builds I use this technique. I get a large cylindrical pencil and put it under the plane and roll it back and forth until the front and the back do not touch the table. This is the "balance point" on the plane. Then I measure approximately 1.0 inches forward of this balance point and I mark it as my CG (approx). I put my battery in and move it to and fro to get the plane to be level when the pencil is under the "CG" mark. This mark is an approx CG point but it is a good starting point. I find that on my jets I still need to move the CG slightly more forward but not much. chas
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But all you are doing is finding the center balance of your plane which has nothing to do with your wing design. Sorry I don't know all the right terminology . The cg is based off of the wing area, design and size front to rear and all that other stuff to come up with a balance point on the design of the wing, not the weight of it. You are just balancing the weight. If I add 4 servos to the rear of your plane and you do your method the cg will be even farther back .
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trying2fly
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But all you are doing is finding the center balance of your plane which has nothing to do with your wing design. Sorry I don't know all the right terminology . The cg is based off of the wing area, design and size front to rear and all that other stuff to come up with a balance point on the design of the wing, not the weight of it. You are just balancing the weight. If I add 4 servos to the rear of your plane and you do your method the cg will be even farther back .


Obviously the CG would be affected farther back by added rear weight but reasonable parameters have been historically presented that dictate that the CG on a fixed wing be in neighborhood of 33% back on wing and about 23% back on flying wings and deltas. You definitely would want to get closer to these figures by being prudent on your weight distribution. This technique has worked to get me in the ballpark for CG on my scratch builds . Very easy understanding of my suggestions is presented by Googling "CG" vs Balance Point/Flight test forum. Contributors Flite Risk,Hai-Lee, and Merv are better at explaining this to you. It is easy to confuse the two concepts especially when I attempt it. I only employed a pencil to find my balance point rather than holding plane with my fingers. chasCG..finding it.PNG  CG..finding it.PNG 
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