In the construction of cottages, garages in the farm economy often have to sift through loose building materials, soil or garden soil. It uses a special device — the so-called roar. His classic version of the frame with the grille installed on the box is a very cumbersome and inefficient. I tried to make it mechanized, as well as more compact and quiet compared to industrial samples.
The first electrographic happened to me not entirely successful. However, the second, revised, was to meet all planned requirements. For the manufacture did not have any need of scarce materials and high qualification of the contractor.