Originally Posted by
speedracerntrixie
It's a combination of nose heavy and too much elevator travel.The OP is running excessive elevator travel to compensate for a nose heavy condition. This would be evidenced by having to hold a fair amount of back stick at slower speeds and a fair amount of forward stick while inverted. I'm also betting that the airplane took a fair amount of up trim when maidened.
I agree.
Let me suggest that the guys whose planes are showing this behavior make all the basic checks such as CG, but don't stop there because the CG shown on the plan may be incorrect. Since the guys who are observing this issue are very observant and cognizant of model behavior, I suspect they would like a more thorough approach. Actually calculate it using one of the online calculators. I've used "RC Aircraft Proving Ground" recipe with good results and use 15% Static Margin for the calculation.
15% Static Margin produces a stable model with no tip stall or high speed stall tendencies. More static margin moves the CG foreward and less moves it back.
One more thing, if the CG is pretty close to where it should be and the elevator required is still 30 degrees, the model has insufficient elevator area. Add area and reduce the throw. None of my designs require more than 15 degrees for the most violent snap rolls. I usually fly with a max of 10 degrees of elevator (mid rate). Even at this deflection, the model snaps fine, just a little more slowly. No reason a pattern model should need any more than that