Design and Fabrication of Straw Cutting Machine

Abstract

The straw cutting machine was designed and built to minimize the time and labor requirement in straw cutting for straw paper processing. The straw cutting machine consists of a set of machine structures, feeding unit, cutting blade unit, power transmission unit and a 1 hp electric motor which was used as a prime mover, The results of the prototype testing revealed that among the blade speeds of 3.03, 6.27, and 7.80 m/min and blade angles of 25, 45, and 65° respectively, the machine performed best at 7.80 m/min and blade angles of 45°, capable of running at 8.39 kg/hr. The percentage of cutting was 64.4% with power consumption was 0.74 kW-hr. Based on the analysis of engineering economics, it was found that the straw cutting machine worked 2,000 hours per year, with an average cost of 50.7 baht per hour. The payback period was 10. 12 months and the break-even point of the machine was 467.4 hours per year. This prototype can work at least 6.7 times as fast as human labor.