The third generation sand making machine, which is also known as energy-saving and high-efficiency tertiary impact crusher, is a comprehensive crusher with the advantages of hammer crusher and impact crusher. With the obvious advantages such as large arc crushing space and advanced crushing theory–"stone impacting stone", this kind of sand maker gradually replaces the vertical shaft impact crusher in the market. On the basis of the second generation sand maker, this machine adds the balance wheel which saves the electric energy and increases the kinetic energy, thus improving the production efficiency greatly. At the same time, this machine adds the back plate adjusting device which makes it easier for adjusting the material fineness. Without opening the enclosure, the material fineness can be adjusted.