A print head is disclosed for use in an additive manufacturing system. The print head may include an outlet configured to discharge a material, and a compacting device mounted to trail behind the outlet during movement of the print head in a normal direction. The print head may also include a spring configured to bias the compacting device against the material and to allow movement of the compacting device in a direction parallel with a discharge direction of the material through the outlet, and a locker configured to selectively lock a position of the compacting device relative to the outlet.