Here is how DJI
recommends to find the center of gravity (CG) of your helicopter.
Remove the main blades.
Hold the helicopter vertically
with the nose pointing
Drop a plumb-line (see plumb bob
indicated by the arrow) beside the
tailboom. This is the X
axis or horizontal line.
For Z axis, or vertical line, balance the
heli on the skids. I
normally grab the tip of the
head and see which direction the
Mine was set up so the CG falls perfectly inline
with the main shaft.
My CG intersects just below the
tailboom. Inline with the
main gear. About 12cm from
the main controller.