Experimental Study of Grass Cutter Blades with Angles Of 15°, 30° and 60° For Animal Feed

Abstract

This research analyzes the needs of the Indonesian agriculture and livestock sectors for efficient, effective grass chopping machines capable of producing uniformly chopped grass for animal feed. Conventional grass chopping machines often suffer from high energy consumption, unevenly chopped grass, and relatively low production capacity. One important factor significantly affecting the performance of a grass chopper is the blade angle. Variations in blade angle can affect cutting force, energy efficiency, cut quality, and even blade lifespan. However, research on the effect of blade angle variations on grass chopper performance is still limited, so this study was conducted to provide both a scientific contribution and a practical solution. The main objective of this study was to determine the optimal blade angle for the grass chopping process, with parameters such as cutting efficiency, production capacity, and uniformity of the chopped grass. The research method used was an experiment with a quantitative approach, testing three variations in blade angle: 15°, 30°, and 60°. The testing process used fresh elephant grass of a certain weight as the test material, which was then chopped using a modified machine. Observed parameters included shredding time, uniform shredded weight, production capacity (kg/hour), and cutting efficiency (%), calculated based on the ratio of perfectly chopped material to the total material fed. The results showed that varying the blade angle significantly impacted machine performance. A 15° angle produced a production capacity of 72 kg/hour with a cutting efficiency of 63%, but the shredded results tended to be uneven. A 30° angle proved to provide the best performance, with a production capacity of 90 kg/hour and a cutting efficiency of 66%. Furthermore, the shredded results at this angle were finer and more uniform, thus meeting livestock feed requirements. Meanwhile, a 60° angle was unsuitable due to potential collisions between the blade and the machine body. Therefore, this angle was deemed unsuitable for the machine design used in the study.