A fused filament deposition head is employed for depositing filament materials on workpieces to join the workpieces together. The workpieces can be of an automotive application, aerospace application, or something else. The fused filament deposition head, in an example, has a feed end, a dispensing end, and a heater. The feed end introduces more than one filament in the fused filament deposition head, as demanded in the larger application. The dispensing end delivers materials of the filaments to the underlying workpieces. The materials are delivered together. The heater serves to heat the filaments as they travel through the fused filament deposition head. The filaments can include a filament having a core portion of liquid-crystal polymer material.