An additive manufacturing system includes a gantry configured to move in a build plane. A platen is configured to support a part being built in a layer by layer process and wherein the platen is configured to move in a direction substantially normal to the build plane. A head carriage is carried by the gantry wherein the head carriage includes ferromagnetic material. The system includes at least one print head where the print head includes a housing and one or more magnets attached to the housing wherein the at least one print head is configured to be coupled to the head carriage through a magnetic coupling between the one or more magnets and the ferromagnetic material such that the print head is configured to move rotationally relative to the head carriage.