Figs. 7 and 8 visualise the designs of a few Jatropha shelling machines available in the market. In summary, the machines can be categorised into two types which are either hand operated or motorised machines. Basically, the hand operated machines have a smaller footprint and are portable and useful in rural areas where no electricity is available. All of the motorised machines consist of a cracking unit (cracking roller, impact blade, shearing mesh or shearing blade) while some of the machines are combined with a separator (vibratory sieve or air-screen unit) for a one-stop shelling process as shown in Table 3. In the cracking unit, the shearing mesh and blade provide stress in the fruits against the fixed part while the design of the cracking roller and impact blade can generate compression and an impulsive force such that the shells can be detached from the seeds.