Collider changes RB rotation point

Hi. I use addTorque to rotate object about origin. With collider rotation point is different. I use empty object with child connected 3D object. I need empty object as rotation point. Because I want to rotate my 3D object about different point instead of CG. My 3D object is heli. I rotate it about point between blades. With collider at heli body , addTorqe rotates my object about center of collider. So, I don't know how to use addTorque at another point instead of collider center.