Structural Design Optimization for Pedal Operated Paddy Thresher using Response Surface Methodology

Paddy is the main crop in India grown in about 44 million ha area. Threshing of paddy is one of the most widely used practice in India. Traditional methods of threshing are still prevalent in most of the parts of North-Eastern region. The farming community of the North-Eastern region faces some difficulties in adoption due to low productivity, inadequate design, and injuries during threshing.This study made an attempt to optimize the most significant design parameter of pedal operated paddy thresher (POPT) such as loop spacing, tip height, drum peripheral speed and number of the strip in the periphery of drum to achieve the optimum threshing capacity using Response surface methodology (RSM) in Design Expert v7 tool. From the analysis of variance (ANOVA), results indicated that the linear term of loop spacing and tip height; interaction term of drum peripheral speed and strip numbers and the quadratic term of loop spacing and drum peripheral speed have more influence on the response (P<0.05). The coefficient of determination (R 2 ) of the model was 0.95 which indicate a good fit between the predicted value and the experimental value. For machine parameter, optimize design dimensions are-loop spacing 4.01 cm, Tip height 5.21 cm, drum peripheral speed 395 rpm and the number of strips 14. At optimum condition of machine parameters,  the threshing capacity was found approximately 53 kg/h with minimal worker’s discomfort.