Potato harvester

This is a potato harvester, simple design, in front of the conveyor is a knife digging soil and goes to the conveyor, conveyor then sifted soil, everything depends on the soil you have, the ground where we planted potatoes is the tough clay so we ll see if this harvester can do the extraction of potato, conveyor is made that we took two chain and welded pieces of flat steel 2 cm long and 0. 5 cm wide, between these pieces we weld steel rod, works perfectly still remains to test it on the extraction of