Design and development of walking type multi-crop power weeder

Designed walking type multi-crop power weeder consisted of 1.8 kW petrol engine, worm gear reduction box, spring steel cutting blades, flanges, rotor shaft, ground wheels, frame and handle. Provision was given to alter its working width in the range of 150 to 450 mm by attachable shafts to rotor shaft serving it to be useful in multiple crops. Rotor shaft diameter was calculated to be 18 mm by considering the maximum tangential force of 75.63 kg acting on it at maximum tangential speed of blade of 2.51m/s at 200 rpm of rotor shaft. The operational speed observed with 6 blades per flange arrangement was faster in okra crop (0.39 m s⁻¹) than in chilli crop (0.38 m s⁻¹). The operational speed observed in maize crop with 6 blades per flange arrangement was slower (0.36 m s⁻¹) than 4 blades per flange arrangement (0.38 m s⁻¹). The field efficiency determined with 6 blades per flange arrangement was higher in okra crop (82.5%) than in chilli crop (80.7%). The field efficiency in maize crop determined with 6 blades per flange arrangement was lower (74.9%) than 4 blades per flange arrangement (77.6%).The 6 blades per flange performed better weeding operation than 4 blades per flange arrangement.