im building a pizza box flier .. well its actually finished its 18x18 with a sfm speed 400 geared 1.85-1 ratio 9x3.8 prop . 8.4 volt 900 mah battery has plenty of power . need to find a few things before i go out for a test flight .. i have my cg set a 4 inches from the front of the craft .. as per ive seen in other threads .. is that correct .. and i need to know what angle of attack the elevator needs to be for a good flying PBF .. it has a 3 inch elevator and a 2 inch rudder ( the control surfaces ) the rudder itself is 4 inches total .. if anyone can help with the angle of attack id apreciate it