Development of weight grader for dehusked coconut.

Grading of dehusked coconut is an important postharvest mechanization needed in the marketing of the dehusked coconut. In India, farmers grade the dehusked coconut manually which is in lack of objectivity, accuracy and lower efficiency. This work aims to design, develop and evaluate the performance of an efficient weight grading machine for dehusked coconut. The developed grader characterized by an electronic weighing assembly, carrier cups with four bar linkage mechanism, proximity sensor, pneumatic actuators, and drive mechanism. Mild steel carrier cups with the tilt angle of 10o was optimised to ensure a free falling behaviour of dehusked coconut as well as return back position of carrier cups. The performance tests indicated that the design parameters viz angular velocity of carrier cup and the signal settling time of the load cell influenced the grading performance at 5% level of significance. An acceptable grading efficiency of 84% was obtained at an angular velocity of 16 rad min-1 and load cell settling time of 4 s. The error found in the weight prediction using load cell was ±10 percent suggesting a higher grading efficiency. Further there was no mechanical damage to the graded coconuts. The local vendors and wholesalers can be benefitted with the developed weight grader as it is user friendly, compact and have reasonable grading accuracy. [ABSTRACT FROM AUTHOR]