I believed that the theoretical CG point is 33% of the Average Mean Chord. Given that the wing has a slight front to back taper at the outer regions I’d have said that ¼ inch behind the spar was the best spot. If she’s too nose heavy then you’ll need lots of up/down movement of the elevator to change the pitch attitude of the plane. If she’s tail heavy, the model will react to the slightest elevator movement.
If I were you John, I’d try the CoG where Erwan suggests and see how she flys. It’s always best to error on the side of caution and keep her a bit nose heavy to start, then move the CG back slowly until she flys the way you want her to.
The way to really check is to fly the model up to a good height. Put her into a 45 degree dive, take your hands off the sticks and watch what she does.
Contrary to logic & common sense, if the model pulls up, out of the dive, then she is too nose heavy…..CG needs to go back.
If she increases the steepness of the dive then she’s tail heavy, CG needs to come forward.
If she stays on the same trajectory, the CG is correct.
Alas, with winter approaching I fear you might have to wait some time before you see any Balmy Days. :!:
They tell me that patience is a virtue. So the question is,………just how virtuous are you? :roll:
Keith
