Additive Manufacturing (AM) has been a frontier topic in the industrial revolution 4.0. Out of several AM techniques, fused deposition modeling (FDM) is the most widely used technique. FDM uses filament as input feeding. The dimensional accuracy of the filament is an essential factor for success in this method. This research is an attempt to fabricate a filament made of polypropylene using a plastic extrusion machine. According to the typical FDM type 3D printer, the target is a filament with a diameter of 1.75 mm. The three main parameters that affect the dimensional accuracy of the filament are varied, namely the heating band temperature band (150-170 oC, 155-175 oC, and 160-180 oC), winding speed (13 mm/s, 16 mm/s, and 19 mm/s), the distance between the roll and the nozzle (200 mm, 500 mm and 700 mm). The experiment was designed according to the Taguchi L9. Minitab 19 was used to determine the S/N ratio and analyze the variance (ANOVA). It proved that temperature and distance significantly affect the diameter of the extruded filament while rolling speed does not significantly affect the filament diameter. Applying a combination of temperature (160-180 oC), nozzle to a winding distance of 700 mm), and rolling speed of 13 mm/s would achieve the best accuracy of filament diameter of 1.73 mm with a deviation of 0.03 mm.