Ergonomics in developing hand operated maize Dehusker–Sheller for farm women

A hand operated maize dehusker–sheller to be operated by farm women was designed and developed to dehusk and shell the maize cobs using ergonomics (anthropometric, strength and physiological workload). Axial-flow maize dehusker–sheller with 540 mm cylinder length and 380 mm diameter required 3.03 N-m torque on cylinder shaft while operating at 5.6 m s−1 peripheral speed and 100 kg h−1 feed rate by feeding cob one by one. This torque was 30% of isometric torque obtained at front position of handle (greatest distance) with lowest crank length. The heart rate of subject while operating the maize dehusker–sheller at 54 rpm (5.6 m s−1) was 142 beats min−1. The output of 60 kg h−1 was obtained at the feed rate of 80 kg h−1. Two subjects can operate the machine for an hour with a rest pause of 15 min by swapping the operation.

► Ergonomics is essential for developing gender friendly equipment.
► 30% of lowest isometric torque enables the farm women for its smooth handling.
► Hand cranking speed of 50–55 rpm may be taken for design of equipment.
► Development and testing simultaneously are good practice.
► Ergonomic designed equipment reduced physiological and economic costs over others.