Hwacheon: Top Preventive Maintenance Tips For Your CNC Machine Tools

Daily / Weekly Preventive Maintenance Checklist For Machine Tools

Most of the daily and weekly preventive checks and maintenance tasks are performed by your machine operators.

These routine maintenance procedures are needed to ensure that your production rate is not slowed by simple errors such as the following:

• Stopping of the machine due to the failure to top up lubrication oil (or worse, have insufficient stocks of the oil)
• Blockage of production as chips – especially aluminum chips – are not cleared, resulting in chips overflow.
• Poor air supply (volume and quality) may result in costly damages. Dirty or humid air can affect product quality.
• The drop of coolant levels below the limit, resulting in overheating and damage.

Rather than blame the manufacturer, you should institute a simple daily or weekly care and maintenance program. Here are some steps you or your operator can take:

Check on levels of coolant

Check on the cutting tool at ATC

Check on hydraulic systems for any leakage

Check on air supply to make sure that it is clean and dry

Check for any leakage or strange sounds

Lubricate machine’s moving parts

Ensure that spindles, chucks, and any moving parts are cleaned by brushes or flushed with coolant.

Check on pneumatic pumps and chucks.

Note: This is very important as the pneumatic operated chucks are highly sensitive and work best when they’re regularly maintained. Damages to the sealing and a lack of lubrication can be very costly to repair.

Ensure that chips are cleaned but not blown off to prevent damage.

Note: For CNC machines, the clearance of chips, dirt, or coolants should not be done by blowing them away with an air gun. This is because an air-gun may push chips and coolant in areas where the machine manufacturer actually spends effort to prevent them from reaching (using expensive covers with wipers, for example).

Quarterly / Semi-Annual Maintenance Checklist For Machine Tools

On a quarterly or six-monthly basis, check that your coolant tanks, air reservoirs, pumps, and drainages for oil work smoothly. You can do so by making sure that they are clean and free to operate.

For example, your coolant tank may collect sludge over time if it isn’t cleaned regularly. Over time, this may not only reduce your overall tank capacity for coolant – it may affect the purity of your coolant and be detrimental to the performance of your spindle. This is particularly damaging if a CTS (Coolant Through Spindle) system is used. Fine chips and particles will be sucked through your CTS Pump, damaging it in time. Your machine’s tool holders and spindle cones may also be damaged.

To prevent such mishaps from happening, do the following every quarter or half-yearly:

Have the coolant tank cleaned of sludge, chips, and oil

Have the chuck and jaws taken off the machine and cleaned

Have the leveling of your machine checked and adjusted if necessary

Have the radiator cleaned while making sure that the radiator fins are straight and not damaged

Have all way wipers inspected for any damage – clean and replace any wipers that are damaged

Have the hydraulic tank drained, and replace the hydraulic oil with fresh hydraulic oil. Do also ensure that the line filter and suction filter are changed.

Have the lubrication unit drained and cleaned out – thereafter; you should add fresh way lubricant.

If your machine is equipped with a cooling unit, have the cooling unit drained and refilled

Yearly Maintenance Checklist For Machine Tools

What about your annual maintenance schedule? How do you keep your machine tool in prime condition year after year?

First, you need to note that the more axis your CNC Machine Tool has (like a 5-axis Machining Centre), the more critical it becomes to keep it aligned and calibrated. For such complex machine tools, you’ll need to check on the status of your machine beds, hydraulic systems, and spindle lubrication systems. You should also test to ensure that your machine tool accuracy and machine tool level can meet your requirements.

Here are some must-dos for your machine tool every year:

Have the spindle checked for radial and end play issues

Have the chuck cylinder checked for running out

Have the tailstock checked for misalignments and quill function

Have the turret parallelism and inclination checked

Have the whole machine checked for leakage of oil or air

Have the headstock checked for any damage or misalignments, and the spindle taper at milling machines

Have your distributor/supplier check the X, Y, and Z-axis gibs and adjust if necessary. Check in the same way the function of your 4th axis table

Have your distributor/supplier run a backlash program to check the backlash in the X, Y, and Z-axis and adjust if necessary

On an annual basis, it is recommended to have a CNC machine check overall done in respect of leveling, accuracy, and functionality. This should be done by the machine manufacturer service engineers or at least by well-trained and factory-certified dealer engineers. These qualified professionals would know what to do and what to look out for – they will also have the equipment at hand to do the job properly.

Conclusion

As the saying goes, prevention is better than cure. Just like a human body, keeping your CNC machine tool in healthy running order will ensure its longevity, accuracy, and productive use over the long term.

Incorporating a regular maintenance schedule is thus a must for shop floors that deploy CNC machines for their production processes.

Beyond keeping your machine in good running order, it is important to invest in high-quality CNC machine tools that are easy to maintain and which come with good after-sales support.

Hwacheon’s machine tools are built with a rigid, top-quality, and long-lasting mechanical design. However, like your precious bodies, you need a program of regular maintenance and care to keep them optimally running for a long time.