There are many main shafts in the grinding workpiece, causing the grinding wheel and the workpiece to swim in high-speed rotation, making the spindle shift, there will be corrugated and vibration in the milling workfoil, so that the main shaft itselfThe dynamic balance is that in one case, the front end bearing of the spindle is taken into water, and the seal is not rusted, and the bearing is rusted so that the bearings are replaced, which is balanced from the new movement, which can fix the spindle.*** The last type is that the spindle itself is rigid. It is not quenched when manufacturing the casing, which directly leads to an abnormal sound in subsequent use, which can only replace the new intensive spindle.