The Routine Maintenance of CNC System

Computer Numerical Control (CNC) System is the core part of electrical control system of a CNC machine tool. After a certain period of time of operation, every CNC system will inevitably face that some of components and parts go wrong or damaged. In order to prolong the service life of components as much as possible and prevent all kinds of failures, especially some serious accidents, CNC system must have regular maintenance. It mainly includes the use inspection of the CNC system and the routine maintenance of CNC system. Routine maintenance of CNC system mainly includes the following aspects:

I. Strictly establish and implement the rules and regulations on routine maintenance of CNC system
Based on the characteristics of different CNC machine tools, the rules and regulations on routine maintenance of CNC system must be established strictly and implemented strictly in use and operation.

II. Only open the door of CNC cabinet and high-voltage electrical cabinet when necessary
Usually there are some oil fog and dusts in the air of the machine shop and once they fall onto the PCB of CNC system or electrical components, they’re likely to cause the drop of the insulation resistance of components, and even cause the damage of circuit board or electrical components. So only open the door of CNC cabinet and high-voltage electrical cabinet when necessary.

III. Clean cooling ventilation system of CNC device regularly to prevent overheating
Cooling ventilation system is the important device to prevent the CNC device overheated. So please make sure every cooling fan on CNC cabinet works fine every day and check whether there is any block in duct filter every quarter or half a year. Clean it immediately if any.

IV. Please pay attention to the regular maintenance of the input/output devices of CNC system
For example, the magnetic head on the input device of CNC system needs cleaning.

V. Regular inspection and replacement of the electrical brush of DC motor
Most CNC machine tools manufactured in the 1980s used DC servo motor, whose brush got the wear problems. So they need regular inspection and replacement of the electrical brush of DC motor.

VI. Often monitor the voltage of electric network for CNC devices
CNC system have strict requirements of the voltage of electric network. For example, the CNC system manufactured by FANUC allows the voltage of electric network in the range of 85% to 110% of rated supply voltage. Otherwise it will cause CNC system not to work, even damages to the internal electronic components of CNC system. So often detect the voltage of electric network, and always make sure it’s within the range.

VII. Regular inspection and replacement of the battery of the memory
Usually the contents of the CMOS memory of CNC systems stays on battery power when the power is cut off. Generally they use Li-ion battery or NiCad Rechargeable Battery. When the battery voltage drops to a certain value, it can cause data loss, so the battery voltage should be inspected regularly. Replace the battery in time when the battery voltage drops to limit or battery voltage alarm happens. The battery should be replaced when the CNC system is working, or it will cause the loss of storage data. If the storage data is lost, it can be re-input after the replacement.

VIII. Maintenance of CNC system that is idle for a long time
When CNC machine tools are idle for a long time, it’s necessary to do the maintenance of CNC system regularly. Use a backup battery to power a chip to keep the data safe when machine tool is not used. If the battery voltage of machine tool is too low, usually an alarm prompt will appear on the display screen. Do the electricity check often to see if there is alarm prompt, and replace the backup battery in time. Regular electrification can prevent machine tools in idle from short circuit or open circuit when electrical components or printed circuit boards are affected by moisture. So electrification should be done at least twice a week.

IX. Maintenance of back-up printed circuit board
The Purchased back-up printed circuit board should be installed on CNC device to get electrified for a moment to prevent damage.

X. Solution to CNC failure
Once the CNC system goes wrong, the operator should take emergency-stop measure, stop the system running, and preserve the scene. And help the serviceman to do the early preparation of the maintenance work.