When we need to enhance the precision of cnc machine during processing, or we need to Maintaining high machining accuracy during long term processing, you could consider installing grating ruler.
Most cnc machine tools adopt semi-closed loop control mode, which means cnc system send commands to the servo drives, servo drives send commands to the servo motor.
Servo motor give feedback to servo driver through encoder about the implementation of the directive, the real moving parts driven by servo motor can’t give feedback about location information, so in this way to generate a semi-closed loop control.
Once cnc machine have gap arising out of step or wear, it will generate large errors, but the system can’t not detect it.
While closed-loop cnc machine, is when cnc controller send commends to servo driver, servo motor, servo motor encoder giving position feedback information, on the servo motor driven part, has inspection device to give location feedback, like grating ruler. In the same time, it give location feedback to cnc controller, all in all to generate a closed-loop control.
Grating scale can’t directly enhance the accuracy of cnc machine, only when the machine is assembled to achieve a very precise degree to help enhance the precision of cnc machine. Therefore, with grating ruler is not high-precision machine. Only follow special, highly demanding production installation process, closed-loop machine is likely to be high-precision cnc machine.
Substrate of grating scale usually is steel, covered by glass or glass ceramics, easily affected by external environment. So, customers should pay attention to cleaning and maintenance in the course of the machine. Remove iron and other foreign matter jamming grating in time, collide it with hard object is absolutely should be avoided.
Grating ruler’s common accuracy grade is 5 microns, 3 microns and 2 microns, usually 5 microns is used in the cnc machining center.
Mainly, we recommend clients use Spanish Fagor brand, high-cost performance.
Note: For general machining parts, requirement for depth is not high, therefore, Z axis may not need to install grating ruler considering lowing cost. However, for mold processing, surface machining, tool set processing, it has a high demand on depth, we recommend the installation of grating ruler for Z axis. Grating ruler also the same as granting, granting scale or linear scale.
