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Old 11-10-2015, 04:06 AM
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Larry3215
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Join Date: Mar 2006
Location: Gig Harbor, Wa USA
Posts: 7,061
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Originally Posted by bgchip View Post
I have a scratch built Lazybee, 50 inch wingspan, electric motor Hacker 30. When it takes off it climbs, stalls, dives, climbs, stalls etc. sort of a scallop pattern. It is probably overpowered. But would it fly like this as a result of incorrect wing incidence, or wrong engine thrust?
One more thing - its important to realize that no single aspect of model setup is independent. Every detail effect every other detail as far as model "trimming". When we talk about trimming a model or setting a models "trim" we dont just mean elevator trim settings.

CG, thrust line, decalage and trim setting all work together. Each one effects the others.

For example, haveing the CG to far forward forces you to add more UP trim on the elevator with in turn means you need more down thrust to keep the model from climbing under power and diving with power off. Having too much elevator down trim would make you want to move the cg back and or add UP thrust, etc etc.

Thats why you need to run through the tests above more than once.
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