Vol. 9, Special Issue 10, Part U (2025)

Finger millet is a nutritious cereal, but manual harvesting is labor-intensive and results in low grain recovery. To address this, a low-cost, lightweight, and farmer-friendly spiral-type finger millet thresher was developed. The machine consists of a main frame, transporting wheels, feeding hopper, wheel cover, electric motor with switch and plug, grain outlet, husk outlet, threshing shaft, adjustable spring, sieving unit, spiral-type cylinder, threshing section, V-belt, and driven pulley. A trapezoidal mild steel hopper ensures smooth feeding, while the spiral-type cylinder with high-strength steel concave efficiently separates grains from stalks. A vibrating sieve removes chaff and impurities, and power is transmitted from a 0.5 hp electric motor via a properly tensioned V-belt and pulley system. The threshing cylinder shaft is made of high-strength alloy steel to resist bending and torsion, and adjustable concave and sieve angles improve versatility for different crop conditions. Performance tests showed a threshing efficiency of 96.41%, cleaning efficiency of 97.34%, broken grain of 2.76%, and a threshing capacity of 28.60 kg/h. Overall, the thresher enhances harvesting efficiency, reduces grain loss, provides clean grain output, and offers a practical, reliable, and cost-effective solution for small-scale finger millet farming.