Topology Optimization of a 3D-Printed Ratchet Wrench Using Polyethylene Terephthalate Glycol

Recent advancements in 3D printing technology have expanded filament choices with improved resistance to environmental factors and mechanical properties. Despite various practical tool studies, a research gap exists for 3D-printed ratchet wrenches. This study aimed to identify robust, commercially compatible material for such applications. Utilizing PETG and Creality Ender 3V2, the ratchet wrench was printed and topology-optimized. Finite element analysis (FEA) simulations and physical tests evaluated mechanical traits. The original design failed at 1.35 Nm due to the shear stress parallel to the print layers. The modified design broke at the compliant mechanism at 2.21 Nm, aligning with FEA’s failure analysis. The topology-optimized version, 56.36% lighter, failed at 2.97 Nm due to the square drive breaking. While PETG proved reliable for lighter workloads, carbon fiber filaments are preferred if accessible.