Swallow 90 CG - what gives?
I am just finishing up a Giant Scale Planes Swallow 90 pattern ship. I have a Super Tigre .90 in the front end with a header pipe to a macs 90 size quiet pipe. Servos are in the wings and radio bay in the openings where they go with no modification. Rudder is pull pull. Elevators are driven by a single carbon fiber shaft with 4-40 ends. A sullivan tail wheel is at the back and a tru turn spinner up front. The plans recomend balance point about 25% behind the leading edge. Without battery this thing is balancing 8 inches behind the leading edge of the wing! Even when I put 1800 ma's of nicads, which I never use, I always use nimh batteries, taped under the fuel tank in front of the gear I only get a balance point 6 inches behind the leading edge of the wing.
Somebody's gotta help me here. I have never had a plane come out so far out of wack. Do I have to go mount a 1.20 in the front end of this thing to get it to balance? Does it fly in the real world with the balance point further back? What do you who have experience with this plane have balance wise? Is my power plant excessively light or what? I'm not interested in flying a plane with a pound of useless lead in the nose. If I have to add that much weight it should at least be producing power. But I really want a .90 size plane. I'm not into 1.20 and bigger power plants. If I have the wrong plane, I'll just sell it.
Thanks,
bob branch