The center of gravity (COG) of the aircraft is an important factor in determining the location of electronic components. The position of the center of gravity in the horizontal direction is between 15%-35% of the average aerodynamic chord length of the wing. The position of the center of gravity in the vertical direction is related to the engine thrust line, maneuverability, and stability, and is generally below the thrust line. The location of the lateral center of gravity, generally near the plane of symmetry of the aircraft, is related to maneuverability. And the goods should be kept near the center line. Therefore, all electronic components should be distributed symmetrically on both sides of the center. Designers should determine the length and distance of each component through modeling (test whether all the locations fit the equipment), and obtain the COG after calculation.
The COG is usually numerically proven using a weight-moment relationship. The point is usually taken as the datum point and the datum line is drawn from it through the body of the aircraft. The distance of the components from the datum point should be noted and multiplied by their respective weights to obtain the moment. The total moment is then divided by the total weight of the UAV.
Here is an example:
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