aerobatic airplane setup

[furn1593]

need some help here - my seagull 300ep wont seem to fly level, and looks out of trim - here is the current setup, climbs like a rocket at full power, needs up elevator inverted... what to adjust, thrust angle, CG, aileron adjustment (move both up or down)...??

[mararra]

I dunno, but I bet ya can find the answer here: www.modelaircraft.org/MAG/FTGU/Part%2029/29main.html
A wealth of info!
M

[av8tor]

Hey Furn,

Not exactly sure what you're asking. Most airplanes will fly level only for a given power setting (I assume by level you mean neither climbing nor descending). With neutral control surfaces and full power you can expect to climb. As for inverted flight, does the Seagull have a symmetrical wing (same curve top and bottom)? Without that (and even with it) it will need up elevator (control stick forward) to stay level while in inverted, as a greater angle of attack is needed to generate the same amount of lift.

Assuming the airplane has no roll tendencies (without input from you) then the ailerons are OK.

CG is pretty forgiving and the airplane should be flyable within an inch or so of optimal.

Thrust angle will affect turning, with zero thrust angle the plane will want to turn left on its own especially at full power and while climbing due to P-factor. Again, like nearly everything else the angle is a compromise for when you need it the most (high power, climbing) and when you need it the least (low power descending).

Does this help?