Design of a Manually Operated Groundnut Shelling Machine for Smallholder Farmers in Kano State

Groundnut processing remains one of the most labour-intensive agricultural activities in North West Nigeria, with manual shelling accounting for a significant proportion of post-harvest losses and fatigue-related injuries among rural farmers. This study describes the design, fabrication, and performance testing of a manually operated groundnut shelling machine suited to the operating conditions of smallholder farms in Kano State. The machine design incorporates a rotating cylinder fitted with rubber-coated pegs that agitate the groundnut pods against a perforated concave screen to separate kernels from shells. Structural components were designed using standard engineering calculations, and materials selected for durability, low maintenance, and compatibility with local fabrication capabilities. The fabricated prototype was tested using three varieties of groundnuts commonly cultivated in Kano, and shelling efficiency, kernel damage rate, and throughput capacity were measured. The machine achieved a shelling efficiency of 91 percent and a throughput capacity of 60 kilograms per hour when operated by a single adult, representing a tenfold improvement over manual hand shelling. Kernel damage rate was recorded at 4.2 percent, within acceptable limits for commercial quality. The total fabrication cost was estimated at 38,500 naira using locally available materials and standard workshop equipment. The study concludes that the machine offers a practical, affordable solution for improving post-harvest productivity among smallholder groundnut farmers. Keywords: groundnut shelling machine, manual operation, post-harvest processing, smallholder farming, Kano State.