It only takes a slight misalignment of aileron trim to get past the point where the rudder can correct for it. On a plane like you had, once the airplane rotates and the nose wheel is in the air the primary roll control is the ailerons. The rudder then becomes secondary to compensate for yaw. The plane is not designed for rudder control as a primary function and you have found that out the hard way. On the first flight of ANY plane, you must be ready to instantly correct for any out of trim conditions and climb the plane to a safe altitude before attempting to adjust the trims. Just as in full size planes, when there is a problem- fly the plane first and figure out how to fix it when you have time. Too many people crash worrying about correcting small problems and forget to keep the plane in the air first.