Considerations 1. wood products should not be washed with blisters 2. The handle should not be idling or rotate counter clockwise to avoid damaging core. 3. in the process of rotation between the big gear and pinion shall not put your finger on it, so as not to hurt your finger 4. choose different grinding fineness according to different instruments, choose fresh roasted coffee beans. 5. in the process of grinding. don't shake the fuselage. lest coffee powder leakage to powder storehouse. 6. Coffee beans can be grind in 2 times, rough for the first time, fine for second times, and easy to grind. 7. If tightening of the screw cap is too tight (screwed to the right), it will be difficult to grind. which is one of the causes of the malfunction.