CNC machine tool actual moving distance is inconsistent with the displayed coordinate values ​​- Database & Sql Blog Articles

Single chip microcomputer STM32L151CCU6

Photocoupler

Siemens 810 CNC system, 611 drive module around 96 years, 1FT5 motor. The equipment used for many years is very stable. The problem was discovered yesterday when the machining parts were too poor. The horizontal X axis moved in the same direction. The table and the coordinate display were inconsistent. The movement was 50-60mm. The difference between the coordinate value and the table value was from 0 to 20. More or less, no rules. The handwheel feed amount is consistent with the coordinate display amount. The positive direction gap is 4 filaments. Semi-closed loop system with motor with encoder. Ask you how to judge and solve.
A: Actually, the position loop response is delayed, and the mechanical following error is out of range.
It is necessary to check all the links of the mechanical transmission, such as whether the connection between the X-axis motor and the table screw is reliable, whether the clearance is appropriate, and whether the inclined iron adjustment of the table is appropriate. In addition, the position of the position detecting component such as the encoder is not normal, which may also cause the fault. The specific method is as follows:
1. First judge whether the mechanical transmission problem, disengage the motor from the lead screw, and gently move the lead screw by hand. When normal, it should feel smooth, no stagnation or pause feeling. Otherwise, it should be determined that the screw bearing is damaged and replaced.
2. If the above is normal, check the backlash of the X-axis of the machine tool. In each position of the X direction, such as the head and the middle position at both ends, the X-coordinate backlash value should be played out with a dial indicator. The result should be consistent. Otherwise, it needs Check to adjust the straightness of the X axis,
3. If the backlash value is not greater than 0.04m, compensate the backlash value to the axis parameter MD32450,
4. If the backlash value is greater than 0.04 mm, inspect the shaft screw bearing and adjust the ball screw to tighten to perform backlash. After the clearance is completed, the test is qualified, that is, it is guaranteed to be within a range of not more than 0.04 mm. If it is qualified, compensate the backlash and continue the test machine.
5. After the above adjustments are normal, if the fault persists, check if the connection of the X-axis motor encoder is loose. After tightening, repeat the test machine to check whether the machine tool malfunction is eliminated.