Let's talk about precision machining!

　　When CNC machine tools are used for mass production of precision mechanical parts, the machining accuracy must be paid special attention to. What issues should we pay attention to in order to ensure accuracy during mass production?

　　First, poor accuracy in batch part processing is generally due to poor adjustment of the feed dynamics between the axes during installation and adjustment. Or due to wear and tear, changes have occurred in the transmission chain of each axis of the machine tool, which can be solved by readjustment and modification of the gap compensation amount.

　　When the dynamic tracking error is too large and an alarm is triggered, check the following: whether the servo motor speed is too high, whether the position detection element is functioning properly, whether the position feedback cable connector is making good contact. Check if the corresponding analog output latch, gain potentiometer, and servo drive unit are functioning properly.

　　Second, overshoot during machine movement causing poor processing accuracy may be due to too short acceleration and deceleration times. The speed change time can be appropriately extended. It may also be due to loose connection or poor rigidity between the servo motor and the lead screw. The gain of the position loop can be appropriately reduced.

　　Third, roundness exceeds tolerance in two-axis linkage

　　(1) Axial deformation of the circle

　　This deformation may be caused by poor mechanical adjustment, resulting in poor axial positioning accuracy. Or improper screw gap compensation may cause roundness errors when crossing quadrants.

　　(2) Oval error

　　In this case, first check the position deviation values of each axis. If the deviation is too large, adjust the position loop gain to eliminate it. Then check if the rotary transformer or synchro interface board is properly adjusted, and check if the gap between the mechanical transmission pairs is too large and if the gap compensation is appropriate.

　　Non-standard precision parts machining has high precision requirements

　　The precision of non-standard precision parts processing mentioned here must be strictly in accordance with the additional drawings. Parts within the allowable error range are qualified parts. Therefore, the requirement for processing precision parts is to strictly follow the theoretical dimensions.

　　The processing of precision parts mainly involves dimensional requirements, such as the diameter of a cylinder, which has strict requirements. Only when the positive and negative errors are within the specified range are they qualified parts; otherwise, they are unqualified parts. The length, width, and height also have specific and strict requirements, and the positive and negative errors are also specified. For example, for a built-in cylinder, if the diameter is too large and exceeds the allowable error range, it will not be able to be inserted. If the actual diameter is too small and exceeds the lower limit of the allowable negative error, it will cause the problem of being too loose and not firm after insertion.

　　These are all unqualified products and must be scrapped or reprocessed, which will inevitably increase costs. Therefore, ensuring the accuracy of non-standard precision parts processing is very important.