①The front and rear top of the CNC machine tool should be coaxial with the center line of the spindle, otherwise the workpiece will not be a cylinder but a cone. To adjust, push the tailstock towards the front of the car and use the tip contacts to check that they are aligned. Then install the workpiece, turn a tool, and then measure the diameter of both ends of the workpiece, and adjust the lateral position of the tailstock according to the difference in diameter. If the diameter of the right end of the workpiece is large and the left end is small, the tailstock of the CNC machine tool should be offset in the direction of the operator; otherwise, it should be offset in the opposite direction.
Offset is best measured with a dial indicator. When measuring, touch the right end of the workpiece with the dial indicator contact. If the diameters at both ends differ by o. 1, then the tailstock should be offset O 1÷2=0 05mm, this offset can be read from the dial indicator.
② Under the premise of not affecting the cutting of the turning tool, the tailstock sleeve should be extended as short as possible to improve rigidity and reduce vibration.
③The shape of the center hole should be correct, and foreign objects such as chips in the center hole should be removed before installation. If a fixed center is used, industrial grease (ie, butter) should be processed in the center hole of the rear center.
④ The fit between the two tops and the center hole of the workpiece must be tight and appropriate, not too loose or too tight. If the top is too loose, the workpiece of the CNC machine tool cannot be correctly centered, and it is easy to vibrate during turning; if the top is too tight, the slender workpiece will be deformed: for the fixed center, it will increase friction, and it is easy to "burn out" the center and the center hole. ; For the rotary top, it is easy to damage the rolling bearing inside the top. Therefore, in the turning process, we must always pay attention to the friction and heat of the top and the workpiece part close to the top. When it is found that the temperature is too high, you must add butter or lubricating oil for lubrication, and adjust the tightness appropriately