One of mechanical devices used to process post harvested corn is a corn sheller. Today, there are many farmers shelling corn manually by their hand, so that manually cranked corn sheller with capacity of 60kg/hrs. Some problems and weakness of the machine were found. Bigger sized cob was stacked off in the frame holder while shelling the corn cob. The objective of this work is to design and develop an improved maize shelling machine in terms of better time management, affordability and mechanical efficiency. The method used involves selecting appropriate materials and utilization of theories of failure that enable the determination of allowable shear stress on the bearing support. It features the design calculations necessary for the completion of this work. The machine can be operated simply by manually. The processing of agricultural product into quality forms not only prolongs the useful life of these products but also increases the net profit farmers make from such products. In this work, emphasis was placed on demand led design which involved understanding the need of the farmer and designing an appropriate system that meets that need. The objectives of the work were to design, construct, and evaluate a low cost maize sheller for rural farmers in Ethiopia. Corn is widely cultivated in Ethiopia. Reducing the post-harvest loss in corn threshing, improvised hand powered thresher is proposed and developed. The test reveals that, device is very useful and effective in shelling any size of corn with insignificant crashing. Moreover, It is a solution for predicament of the farmers most particularly the corn threshing during power interruptions. Besides to this, being economical, this device can be made using only materials that are locally available in market. The only limitation of the device is that, the output in threshing varies depending upon the speed and strength of the operator.