Investigating the Effects of Rope Material Properties on Torque Amplification

Aim: This study explores a mechanical torque booster’s development and performance evaluation based on the capstan principle. The system amplifies torque by utilizing a rope wound around a motor-driven drum, where friction and the number of rope loops determine the force required to lift a load. Methods and Statistical Analysis: A gear train is employed to achieve the desired counter-rotational motion of the drums, optimizing power transmission. The system’s components were designed using theoretical approaches and validated through strength analysis. Modeling was conducted in Unigraphix NX- 8, while structural analysis was performed using Ansys Workbench 16.0. The fabricated system underwent testing to assess its performance, with a comparative evaluation of two rope materials—leather and cotton. Experimental results indicate that with a cotton rope, the highest torque output of 3.3 watts was achieved at 86 rpm, with a power amplification factor ranging from 1.42 to 2.14. In contrast, the leather rope demonstrated superior performance, reaching a maximum torque of 3.7 watts at 86 rpm and a power amplification factor between 1.44 and 2.319. The findings highlight the influence of material properties on torque amplification, providing valuable insights for optimizing mechanical power transmission systems. Major Findings: This study develops a mechanical torque booster using the capstan technique, enhancing torque and power output through a rope-wound motor-driven drum. Experimental analysis comparing leather and cotton ropes revealed superior performance of the leather rope, achieving a maximum power amplification factor of 2.32 at 97.4 rpm. Results highlight the system’s efficiency in mechanical positioning and load-lifting, emphasizing the impact of rope material, spin count, and rotational speed on performance.