Advantages of length manual soymilk machine: decorative function, suitable for home use Disadvantages: slow speed, easy to generate friction heat. It is laborious and time-consuming, and it is quite laborious to use. 2. Advantages of the home propeller electric bean mill: small, light and fast. Disadvantages: The propeller bean grinder cuts coffee beans, which easily leads to different shapes of coffee beans. 3. Advantages of home electric grinder with grinding disc: small, light and fast. Disadvantages: it can't be continuous for a long time, it is easy to get hot, and the heat resistance of the motor and fuselage is poor. The common soymilk machines in the market are propeller type and gear type. Advantages of propeller type: low price. Disadvantages: 1 Because the beans are "chopped" into particles, the size of the ground powder is uneven, and the ground particles are massive. This irregular coffee powder is not easy to extract evenly. 2. Its grinding efficiency is very poor. Long-term grinding and the following high-heat motor will burn beans at the same time when stirring, which will destroy the fragrant coffee oil. 2. Advantages of the gear-type bean mill: Because the beans are "torn", extremely fine and uniform coffee powder can be removed. Under the microscope, it is porous and irregular particles with strong cake crumbs, which can be evenly extracted with hot water. Moreover, the general gear-type bean grinder is more advanced, which is reflected in the price and technology. The gear-type bean grinder uses the clearance between gears to adjust the grinding, and the grinding temperature is relatively low, which can ensure the original flavor of coffee to be preserved.