Cassava is a root and tuber crop grown across the globe mainly for consumption and industrial purposes. It takes about two to three days to deteriorate after harvest, hence the urgent need to speed up its postharvest handlings. Cassava tubers are mostly chopped into different sizes, dried, and stored for more days; this has led to the development of different chipping/chopping machines which produce fixed chopped-sizes of tuber as the desired results. This study is to design a portable cassava chopping machine that is capable of producing different chopped-sizes of tubers. The machine uses shear strength caused by the rotary motions of the blades to chop the tubers. After theoretical evaluation, the machine has 814.4-1227.4 kg/hr capacity, ≥95% efficiency, and no/minimal flesh losses/mechanical damage. This machine is simple to operate and it is recommended for small, medium, and large-scale cassava processors.