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?

　　1. Poor accuracy in batch processing of parts 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. Whether the corresponding analog output latch, gain potentiometer, and servo drive unit are functioning properly.

　　2. Overshoot during machine movement causing poor machining accuracy may be due to too short acceleration/deceleration time, which can be extended appropriately. It may also be due to loose connection or poor rigidity between the servo motor and the lead screw, which can be improved by appropriately reducing the gain of the position loop.

　　3. Roundness exceeds tolerance during 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 whether the interface board of the rotary transformer or synchro is properly adjusted, and check whether the gap between the mechanical transmission pairs is too large and whether the gap compensation is appropriate.

　　Non-standard precision parts machining has high precision requirements

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

　　The machining of precision parts mainly involves dimensional requirements, such as the diameter of a cylinder, which has strict requirements. Only parts within the specified positive and negative error range are considered qualified; otherwise, they are unqualified. Length, width, and height also have specific and strict requirements, with specified positive and negative tolerances. For example, for a recessed cylinder, if the diameter is too large, exceeding the allowable error range, it will not be able to be inserted. If the actual diameter is too small, exceeding the lower limit of the allowable negative error, it will be too loose and unstable.

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