I would like to ask how the plane flies at cruise when it is efficient. I would like to focus on the lateral (up-down) characterisitcs of the flight.
Assuming that the static set up for the plane is as these:
Balance point should be at rear wing post for say a 10 cm chord wing to last years rules. 1-2 cm if front of rear post for a 12-15 cm wing. 2-4 cm behind wing for a 5 cm bonus wing.
Wing level with motor stick (I use top of motor stick for my consistent reference on angle of attack) fore and aft.
Prop should be pointing SLIGHTLY (2 degrees or so) left and down.
Leading edge of tail should be 2-4 mm lower than trailing edge with respect to wing level (or again, top of motor stick).
During level flight, I would expect the wing's angle of attack to be positive, the stab's angle of attack to be slightly positive. This means that this plane flies nose up at the same angle as the wing's angle of attack. I also assume that the prop's thrust points up, less than the nose but still up.
I ask because I see different static set up in the plans of different designs of indoor planes. Here are some that I see:
1 prop thrust level, wing incidence positive, stab incidence slightly positive (as in the Freedom Flight kit)
2 prop thrust negative, wing incidence level, stab incidence negative (as jander's above)
3 prop thrust level, wing incidence level, stab incidence negative
Do these different set ups basically lead to the same flight characteristics? One set up that confuses me is the down thrust of the prop. What is its significance?
In the planes we fly, #1 above is the static set up. During cruise, the nose is slightly up. One thing I notice is that during flight, the tail boom tends to bend a little up so that the stab is almost level during flight. The wing's angle of attack during flight is slightly higher than its static incidence.
Answers and comments welcome!