THE DEVELOPMENT OF A SWEET TAMARIND POD SORTING MACHINE PROTOTYPE FOR SWEET TAMARIND ENTREPRENEURS

Abstract

The objectives of this study were to develop a prototype, evaluate its operational efficiency, and conduct an economic feasibility of sweet tamarind pod sorting machine prototype for tamarind entrepreneurs. The research methodology employed the engineering specifications synthesized from users’ requirements using the Quality Function Deployment (QFD) technique together with ergonomic principles. The process involved designing a prototype blueprint, building the prototype, testing its performance, analyzing energy consumption, and assessing its economic viability. The prototype of sorting machine operated with a conveyor belt speed of 0.82 meters per second. The processing time for tamarind pod size classification was 230 milliseconds, while the processing time for pod sorting was 40 milliseconds. The system was designed to sort straight tamarind pods of the "Sri Chompoo" variety and curved pods of the "Sri Thong" variety into two size categories of long and short pods, as specified. An infrared sensor was used to detect pod length, with the sensor distances set at 75 millimeters for straight pods of the Sri Chompoo variety and 90 millimeters for curved pods of the Sri Thong variety. The system was controlled by an Arduino Uno R3. The performance test results indicated that for sorting straight tamarind pods, 153 long pods and 191 short pods were sorted, with an average processing time of 2.65 minutes. The average number of pods sorted by size was 150.00 long pods and 160.33 short pods. The accuracy of sorting long pods was 98.04%, while that of short pods was 83.94%. The average number of damaged pods after sorting was 7.33, accounting for 2.13%. For sorting curved tamarind pods, 115 long pods and 110 short pods were sorted, with an average processing time of 2.41 minutes. The average number of pods sorted by size was 110.33 long pods and 94.33 short pods. The accuracy of sorting long pods was 95.94%, while that of short pods was 85.76%. The average number of damaged pods after sorting was 6.67, accounting for 2.96%. The electrical energy consumption was 0.814 units per hour, with an electricity cost of 3.18 THB per hour. From an economic standpoint, the total operating cost of the machine was 72.96 THB per hour, and the break-even point was at 1,589 operating hours per year, payback period was 0.02 years. The research results offered a solution to improve tamarind sorting quality by reducing the incidence of mixed-grade tamarinds, and decreasing processing time and labor costs.