Per Tom's manual:
"Put the two wings on the wing tube and pull a string from tip to tip along the centerline of the wing tube
and mark the wing tips along this string line. Balance the plane by picking it up at the tips with your
finger (and a helper’s as well). If the nose drops it’s nose heavy, if the tail drops it’s tail heavy. At this
point it should be just slightly nose heavy for the first flight."

Good luck with the maiden.