An exemplary additive manufacturing system may include an extruder having an opening dimensioned to receive a material. The extruder also may have a barrel and a screw within the barrel. The screw may have a diameter ranging between about 20 mm and about 150 mm and the barrel extends along a longitudinal axis. The system may include one or more heaters positioned along at least a portion of the barrel. As the material passes through the barrel, the one or more heaters may at least partially melt the material. The system may further include a gear pump in fluid communication with the barrel for receiving the at least partially melted material. Additionally, the system may include a nozzle in fluid communication with the gear pump for depositing the at least partially melted material. The system also may include a vertical worktable.