Design of roller type metering device for precision planting

Scattering of seeds is one of the problems in the hill-dropping planters with a roller-type-metering device. For crops like rice, corns and beans, precise hill dropping is known better for a high yield than drill planting and its demand increases gradually The roller-type-metering device is simple in its structure and easy to manufacture so that it is widely used for planting machines: However, it has a problem of scattering of seeds when the seeds are placed on rows. Therefore, a considerable amount of effort has been made to solve the problem so that it can place a desired quantity of seeds per hill at equally spaced intervals. In this study, a method was developed to design the roller-type-metering device for precision planting. Design parameters affecting the uniformity of seed placements were investigated from the geometry of roller and brush. The method was then applied to the design of a metering roller of rice seeding machines. Experimental results showed that the designed metering roller made a better performance of seed placement than that made by the previous one. The method can also be applied to the design of metering devices for precision hill droppings of the other crops.