<![CDATA[The fused deposition modeling (FDM) process is an additive manufacturing technique that fabricates 3D objects through layer-by-layer deposition of molten material. This study aims to determine the optimum process parameters for fabricating onyx-glass fiber composites with maximum impact strength. Onyx, a nylon-based filament filled with micro-carbon fibers, was selected because it is stronger and stiffer than conventional ABS and can be reinforced with continuous fibers. This optimization is important for lightweight structural components, such as electric-vehicle gears, where durability and resistance to dynamic loads are required. The Taguchi method with an L9 orthogonal array was applied, with three parameters investigated: filling density, number of wall layers, and number of glass fiber layers. Impact testing was conducted in accordance with ASTM D6110-10 using a Charpy impact tester. ANOVA results indicated that the number of glass fiber layers was the only factor with a statistically significant effect on impact strength at the 95% confidence level (P = 0.043), while the number of wall layers was statistically insignificant (P = 0.468). Filling density showed a marginal contribution to impact strength (P = 0.073). The optimum combination within the investigated parameter range was identified as 30% filling density, two wall layers, and 18 glass fiber layers, producing a maximum observed impact strength of 0.375 J/mm2.]]>
