What issues should be considered during precision machining?
When CNC machine tools are used for batch machining of precision mechanical parts, special attention must be paid to machining accuracy. So, what issues should be considered during precision machining? Below, we'll introduce three aspects:
1. Poor machining accuracy in batches of parts is generally due to improper adjustment of the dynamic feed error between axes during installation and adjustment, or changes in the transmission chain of each axis after wear. This can be resolved by readjusting and modifying the clearance compensation.
When the dynamic tracking error is too large and triggers an alarm, check the following: Is the servo motor speed too high? Is the position detection element in good condition? Is the position feedback cable connector making good contact? Are the corresponding analog output latches and gain potentiometers in good condition? Is the corresponding servo drive device functioning properly?
2. Poor machining accuracy caused by overshoot during machine tool movement may be due to excessively short acceleration and deceleration times. The speed change time can be appropriately extended. It may also be due to a loose connection or insufficient rigidity between the servo motor and the leadscrew. The gain of the position loop can be appropriately reduced.
III. Roundness Errors During Two-Axis Linkage
(1) Axial Deformation of the Circle
This deformation may be caused by improper mechanical adjustment. Poor shaft positioning accuracy or improper lead screw backlash compensation can lead to roundness errors when crossing quadrants.
(2) Oblique Ellipse Error
In this case, the position deviation values of each axis should be checked first. If the deviation is too large, the position loop gain can be adjusted to eliminate it. Then check whether the interface board of the rotary transformer or inductive synchro is properly adjusted, and then check whether the clearance of the mechanical transmission pair is too large and whether the clearance compensation is appropriate.
