I am Old School But, you can always get close on a staight wing by balancing the plane from about 1/3 back from leading edge.A bit more complex with a swept wing.Try balancing it from a point that bysects the wing in the middle when a line is drawn connecting wingtips.See what happens when you hold the plane at the front of wingtips on swept wing?AS you would never add water to a Habitat Soup.Never make your plane (Tail Heavy) It will try to stall in lavel flight !