How Do Top-Notch Shops Manage CNC Machine Maintenance?

“If it works, don’t touch it!”

Manufacturers lived by this rule in the early days of CNC machining. In fact, CNC machine maintenance was purely reactive, and manufacturers were fine with using their machines till they broke down. However, everything changed after downtimes started getting longer, resulting in losses worth thousands of dollars.

Today, top-tier manufacturers implement preventive maintenance practices to mitigate these challenges and avoid unplanned downtime or operational inefficiencies. This article will cover some of the best preventive maintenance practices you should carry out to get the most out of your CNC machines.

What is Preventive Maintenance?

As the name suggests, preventive maintenance is a type of maintenance that you perform on a machine to prevent accidents or failures from occurring. These routine maintenance activities ensure that your machines work the way you intend them to work.

For example, a typical preventive maintenance routine for a CNC machine would be to clean the machine, remove chips or metal fragments from the chip pan, and apply grease to dry spots.

You’re probably familiar with these preventive maintenance routines. However, there’s more to CNC machine maintenance than meets the eye. For instance, some preventive maintenance routines are best performed daily, while others could be monthly, bi-annually, or annually.

Let’s dig deep into some of the ideal preventive maintenance schedules for CNC machines.

CNC Machine Maintenance: Daily Activities

Here is a list of daily maintenance activities you (or your machine operator) must perform on the CNC machine.

1. Check the lube and hydraulic oil level. CNC machine manufacturers typically specify the adequate fluid level that allows desirable machine performance. If you notice that your machine suddenly starts consuming fluid excessively, it might be an early sign of other problems.
2. Check the hydraulic fluid pressure. We recommend a hydraulic pressure of 4.5 MPa for CNC machines.
3. Clean the machine. Wipe down all the surfaces of the machine to remove shop grime and metal chips resulting from cutting operations. We recommend using rubbing alcohol, rags, brushes (of varying sizes), and metal polish to clean your machines.
4. Apply grease to dry spots. You want to check all moving parts for dry spots and apply grease to these spots.

These activities might look quite simple (and they are). However, small oversights can pile up, causing more serious problems in the long run. Therefore, we recommend performing these checks at the end of each shift (or workday).

CNC Machine Maintenance: Monthly

Unlike the regular daily maintenance activities, we recommend that you have more intensive check-ups and maintenance activities performed by professional engineers (or specialists). These engineers are typically approved by your CNC machine distributor (or manufacturer). And they typically will perform the following maintenance activities:

1. Remove metal chips and apply grease to the chain on the chip conveyor.
2. Clean the filters on the coolant tank.
3. Check and remove debris from the vertical machining center’s pallet changer and receiver areas.

CNC Machine Maintenance: Bi-annually

The CNC machine specialists and engineers must perform the following maintenance activities every six months.

1. Clean the coolant tank. Remove any oil, sludge, or chips resulting from manufacturing operations.
2. Drain and refill hydraulic oil. CNC manufacturers typically recommend that you drain (and refill) hydraulic oils every six months (or after 1000 operating hours). After you drain the tank, change the line and suction filter before refilling the tank with fresh hydraulic oil.
3. Clean the radiator and ensure that the radiator fins are straight.
4. Remove and clean the chuck—the part of CNC lathes that hold and rotate workpieces.
5. Remove contaminants in the spindle and spindle drivetrain that may otherwise affect the overall life of the spindle. Also, ensure that the spindle belts satisfy the manufacturer’s tension requirements to avoid compromising your parts during cutting operations.
6. Check the alignment of the machine’s plane by performing a ballbar test—which monitors the spindle movement as it follows a programmed circular path.

CNC Machine Maintenance: Annually

Once every year, you should contact your CNC machine manufacturer (or distributor) to perform the following checks:

1. Remove and check the chuck cylinder for runout—which occurs when your chuck does not rotate in line with the main axis, causing inaccuracies during cutting operations.
2. Run a backlash program to check for backlash in the machining axis. Backlash occurs when the moving parts on your machining axes do not engage with a sufficiently tight fit to one another.
3. Check the CNC machine’s headstock and tailstock for tapering.
4. Check the turrets for parallelism and inclination to avoid jams, hang-ups, and indexing issues.

CNC Machining Services: Gensun Can Help

Now that you understand how CNC machining maintenance works, you’d agree that a proper preventive maintenance plan keeps machines running efficiently and ensures high-quality machined parts.

Gensun Precision Machining is a leading provider of CNC machining services across Asia. Not only do we have state-of-the-art CNC machines, but we also have expert machinists and engineers who implement our extensive preventive maintenance plan. This keeps our machines running efficiently at all times, ensuring you get your product done right and on time.

Learn more about our CNC machining services.