I have just gotten my first airplane (I have been flying helicopters for several years).
The plane is a Multiplex FunCub with flaps.
This weekend I flew it for the first time. (First time ever with a plane)
My question is regarding trimming of the elevator/CG/downthrust.
The motor is quite powerful for the plane, but then also quite heavy, and i struggle to achieve the CG stated in the manual
If i have the elevator set "flush", the model will dive if i am flying with raised flaps. It will fly straight at certain speeds if i have lowered the flaps.
I have then used the trims on the Tx to have it fly straight when i have raised flaps, however this means the elevator has some throw "by default". The trim was about 15 notches on my Hitec Optic 6. I have not measured the angle/throw of the Elevator in this position.
Flying with the elevator like this works, however i am concerned that this is not the best way to get it to fly straight, and that it might have negative effects on stuff later.
Also I have to fly VERY slow for it not to try to climb with neutral elevator with flaps lowered.
Coming from helicopters, i prefer to have everything as mechanically straight as possible before adjusting on the radio.
I would assume that it should be possible to achieve a trim that would include flush elevator causing the plane to fly straight at some reference speed with raised flaps. And straight at another (lower) reference speed with lowered flaps.
Options I can think of:
- Move CG further back by adding weight to tail (probably the best option)
- Reduce motor downthrust
- Add Flaps->Elevator mixing that would change elevator neutral position depending on flaps position
- "Finalize" the elevator trim i have now, by moving the links, and then zeroing the Tx, accepting the angle on the Elevator.
Any suggestions or ideas will help me greately!