Design and construction of a manually operated tomato sorting machine.

Abstract

Tomato is a major crop of world commerce and supplies the essential nutrients in human diets. Tomatoes are widely grown and used by very many people in Uganda and other Nations. The increasing consumer population has created market for both raw tomatoes and their products, thus encouraging higher production and mechanization. One of the challenges faced by the tomato growing and processers is sorting of tomatoes. Most of them employ human labour to do the work; this becomes expensive by consuming a lot of money that would be part of their profits besides the inaccuracy of the method. Others who attempt to purchase existing tomato sorters find them expensive and not compatible to their scale of production. As a result, this has caused a need for the design and construction of a simple tomato grader which will be easy to operate, cost friendly to both medium and large scale tomato farmers and producers, does not require electric power and has high accuracy. The designed machine will solve the problems of inaccuracy and high costs of human beings in doing the work. It is easy to operate by all users, easy maintain an. repair, not gender sensitive and operates at the lowest costs possible. It has been made of different component parts such as the power unit, the sorting unit, the frame and feed unit. The machine has been. constructed from simple materials possible and available. It helps in the sorting of tomatoes according to their sizes of large, medium and small. To achieve the required design, forces acting on the different machine component parts were analysed using the appropriate formulae for both load and no load conditions, material properties were considered, a favorable design made and proper materials selected for construction. The dimensions of the parts were also determined basing on the size and capacity of the machine required besides standard principles. After -all the processes to design the machine components were constructed from selected materials, assembled and tested for performance.