An additive manufacturing system for printing three-dimensional parts, the system including a print head configured to print a part material along a non-vertical printing axis, a non-horizontal print foundation configured to receive the printed part material from the print head to produce the three-dimensional part in a layer-by-layer manner, a drive mechanism configured to index the print foundation along the non-vertical printing axis, and a controller operably coupled to control the print head and the drive mechanism. The controller is configured to cause the print head to print the part according to a method of printing including printing a support structure below the part on the non-horizontal print foundation, wherein the part and the support structure are physically separated, and wherein the support structure is configured to support the part during printing as the part is elongated.