Balancing the Something Extra
#1
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From: Aurora,
CO
Getting ready to put the bird in the air, the instructions don't specify to balance it upside down or upright, which way should I do this?
Joe
Joe
#2
I just balanced mine within the last two weeks and maidened mine last Sunday. I used a Great Planes CG machine and found it difficult either way. I ended up doing it upside down. I got it as close as I could, but found it a problem to keep it level. If it dropped the tail just a little, it would continue to drop. However, with the same weight on it I could push the nose over and it would also drop. I ended up getting it as close as I could with just a little of more drop on the nose than the tail. I must of got it right because I needed only two clicks of up elevator when I flew it. A mid wing plane is tough to balance either way. Others on here have suggested the "sling" method, but I have not used it. You might want to search and find an explanation on how it is done. Hope my explanation isn't too confusing. BTW: This is a fun plane to fly. I have only two flights on mine now, and can't wait to get back out to the field this weekend.
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From: Aurora,
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Well, I think I'll do it upside down and slightly nose down, it's tail heavy, and all electronics are placed per plan, I got a set of low bounce wheels that are heavyer than the foam one I wanted to use, I may end up moving the battery forward if the wheels don't cut it. I want to maiden this bird next week.
Joe[8D]
Joe[8D]
#9

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Tall Paul has a web page on the Somethin Extra. He calculates the center of gravity should be an inch back from where the plans show.
http://www.angelfire.com/indie/aerostuff/washin.htm
Food for thought,
John
EDIT-> Look at the bottom of the page.
http://www.angelfire.com/indie/aerostuff/washin.htm
Food for thought,
John
EDIT-> Look at the bottom of the page.
#10
Joe: Mine was a little tail heavy as well. After moving the battery and RX as best I could, I ended up adding 1/2 oz in the nose. I epoxied 1/4" oz to each of the engine mount arms. (Placed them on the underneath side as far forward as possible) This worked for me, but not sure how tail heavy yours might be. My battery is underneath the tank shelf in front.
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From: Aurora,
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Finally done, after almost 6 months of on and off building, she's ready for maiden, I ended up putting on the Dubro Low Bounce Wheels, part # 275R, the battery under the tank and 3oz of lead in the electronics compartment, it's very sensitive at the balance point, but I think once I get fuel in it, everything should be fine. Here is a picture of what I did and the finished product.
Joe[8D]
Joe[8D]




