We report on the development of a 3D printing process dedicated to the production of soft glass optical fibers. Direct printing with a miniaturized crucible for melting glass blocks with a pneumatic extrusion head was established. For 3D printing, a developed in-house heavy metal oxide glass was used. Contrary to previous studies on 3D printing of optical fiber preforms, the proposed process is based on the deposition of straight horizontally-oriented lines with a diameter of 300–500 µm to replace standard stack-and-draw manual assembly technique typically used in the development of microstructured optical fiber preforms. A test fiber preform composed of 2500 microrods with dimensions of 60x25x25 mm was printed. As a proof of concept, a photonic crystal fiber preform composed of a solid core and 3 rings of air holes in photonic crystal cladding was printed, and further processed into the optical fiber using a standard fiber drawing tower. We measured a single mode performance of fabricated fibers at 1.55 µm, and flat dispersion in the range of 1.6 – 2.2 µm with zero dispersion wavelength at 1.70 µm.