ORIGINAL: mbilar1
I think I'm good! My CG is right on the main spar with tank empty, my CG (or finger balance point) is within the limits according to the calculator with or without the ailerons included in the wing chord. I will have an instructor take it up and trim it for me just to make sure because I am a newbie. The throws are toward the low end.
Aerowoof, one more question: Wing loading w/empty tank is about 18. With my wing area at 780 sq. in. are you telling me by your rule of thumb this plane could handle 7.8 lbs. without being a tank? Right now it wieghs in at abt. 6 lb. Doesn't engine size also factor in?
And what about prop size and pitch? I'm wanting it to be a "gentle" trainer at this point. (Maybe this should be in the aerodynamics forum). It has a 10 X 6 prop now. Help a newbie get his head around thrust etc. Thanks.
Sounds like you have it fixed. As for your question to Aerowoof, yes your plane would fly even if it was 7.8lbs. (8 lbs.) assuming you have enough power to pull it. Grass runways require more power to get up to airspeed. I had a buddy with a .40LA that could not get his 6 lbs trainer up to speed unless the grass was freshly cut. If you have a smooth (paved/concrete) runway you would just have a longer take off role. In general a plane with higher wing loading will have a higher stall speed. Thus it will have to be landed at a faster speed. So to keep things slow and "gentle" you will want to keep it as light as possible. Also larger diameter props with shallow pitch tend to fly slower but provide more grunt pulling power... Could help with taller grass.