Precautions: To avoid any injury, when the machine operates, please do not touch the grinding wheel or polishing wheel on the machine. Please do not use the machine when the power supply can't meet the requirements (voltage and frequency). You must make sure the details of the power supply your use. Do not put the machine at any place with high temperature or direct sunshine. If any liquid or material enters the inside of the machine, please immediately turn off the switch and pull out the power plug. The machine can't be operated again until it has been checked and repaired. Except the original parts of the machine, other part can't be assembled onto the machine. Do not overload the machine, and do not impact any part of the machine. If the machine is not used for a period of time, please pull out the power plug. During the operation, please maintain the water level of water tank and keep the surface of grinding wheel moisture. When the grinding wheel has been used for a period of time, grinding fatigue will appear (failing to grind in). In this case, use the oil stone stick to recondition the wheel. While this is being done, open the water valve.