Inspect way wipers, note recommended replacements
Inspect operation of all sliding covers
Inspect, correct fluid leaks (hydraulic, coolant)
Inspect conditions of all external cables, wire harnesses, wire tracks
Inspect slide rails and ball screws for ware and lubrication
Inspect and grease counter balance chain
Inspect, adjust voltages: incoming, power supply
Check machine level
Verify ATC Home Positions
Check axis alignments
Inspect spindle taper, note any damage
Set backlash, record findings
Inspect and clean tool pockets
Clean and inspect way lube system, note any problems
Clean axis drive heat sinks
Change hydraulic fluids (customer to supply)
Change hydraulic filter
Inspect and clean cabinet fans
Inspect and clean motor fans
Run spindle, note any heat, vibration or noises
Move all axis in rapid mode, check for smoothness, note condition
Adjust gibbs, if required
Clean chip removal system with help of customer
Ball Bar test (optional, additional costs may apply)
Laser Positioning test (optional, additional costs may apply)
[Checklist] Top Preventive
Maintenance Tips for Your
CNC Machine Tools
by Hwacheon Asia | Aug 6, 2021 | Blog, Resources
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 machine due to the failure to top up lubrication oil (or worse, have
insufficient stocks of the oil)
Blockage of production as chips – especially aluminium chips – are not cleared,
resulting in chips overflow
Poor air-supply (volume and quality), which may result in costly damages. Dirty
or humid air can affect production quality.
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 programme. 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 toolholders 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 levelling 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 run 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 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 levelling, 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 comes 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 programme
of regular maintenance and care to keep them optimally running for a long time.
