1. Function introduction
Nowadays, general CNC machine tools are controlled by a semi-closed loop, that is, the system can only know the rotation angle of the motor through the motor encoder, but not the position of the worktable. During the mechanical assembly process of the machine tool, due to the error of the screw itself and the assembly error , Resulting in micron-level errors during the operation of the machine tool. When the position accuracy is detected by the laser interferometer, the machine error can be detected. Through the error compensation function of the FANUC system, the accuracy of the machine tool can be compensated, thereby reducing the pitch error Impact on machine positioning accuracy!
This file is used on the X axis of FANUC 0i-T CNC lathe. The test uses the one-way compensation function of pitch error. The X-direction motor is directly connected to the screw through the coupling. The transmission ratio is 1:1. The stroke of the X axis of the lathe is 400mm, the parameter N1320=380 (the maximum limit of the positive direction of the X axis); N1321=-20 (the negative limit of the X axis); N1240=330 (the position of the X axis reference point); because most of the machine tool stroke is in the reference The negative direction of the point, so one point is compensated after the reference point, the compensation is divided into ten sections, and the compensation interval is 30.30mm;
2. Parameter setting
N8135#0=0 NPF pitch error compensation function is valid (setting this parameter needs to be saved after power off)
N1006#1#0=0; 0 ROS; ROT linear axis
N3620=10 The pitch error compensation point number of each axis reference point (setting this parameter needs to be saved after power off)
N3621=1 The pitch error compensation point number closest to the negative side of each axis (setting this parameter needs to be saved after power off)
N3622=11 The pitch error compensation point number closest to the positive side of each axis (setting this parameter needs to be saved after power off)
N3623=1 pitch error compensation magnification of each axis (setting this parameter needs to be saved after power off)
N3624=30.30 The pitch error compensation point interval of each axis (setting this parameter needs to be saved after power off)
N3625=0 The amount of movement per rotation of the rotary axis type pitch error compensation (setting this parameter needs to be saved after power off)
3. Setup steps
3.1 The repeated operation of the machine tool is detected by the laser interferometer, and the pitch error compensation chart is obtained;
3.2 Click the function key [SYSTEM]----Pitch compensation---operation, and then input the X-axis pitch error compensation from No. 1 - No. 11;
3.3 Use the laser interferometer to check the positioning accuracy of the machine tool again, and the accuracy of the machine tool will be within the allowable range of the machine design.
