Regular Cleaning for a Healthy CNC Machine

by | Jul 29, 2020 | Diversified Machine Systems

person spraying disinfectant on paper towel

With the outbreak of COVID-19, cleanliness has become a major focus of public concern. Things that should have been the norm—wash your hands after flushing, don’t cough without covering your mouth—suddenly took on greater significance. These daily practices matter. We are seeing in real time the life-changing effects of regular cleanliness—or the lack of it.

The same holds true for a CNC machine. Regular cleanings keep a machine up and running for the long haul. By contrast, neglecting regular cleanings can damage a machine and lead to unwanted downtime and costly repairs. When a machine stops hitting tolerances and performing correctly, people will often pay to have a specialist inspect it. The specialist arrives, only to discover that the problem is very simple: the machine hasn’t been cleaned properly.

One of our main goals at Diversified Machine Systems (DMS) is to save you time and money. To that end, here are some helpful instructions on cleaning your CNC machine.

The Essentials

To begin, make sure you have a few essential items on hand. A manual might seem like a waste of shelf space, but it contains important info about your machine that will help you make the right cleaning decisions. (If you misplaced the manual on a DMS machine, we’re happy to send you a new one.) We also recommend keeping a lint-free rag in a sealed bag. If you store it next to your machine, it will serve as a reminder for daily cleaning tasks. Many machine operators also keep an air gun or vacuum handy.


Different cleaning tasks require different frequency. Some tasks should be performed daily— cleaning the machine, checking lubrication, vacating water. Other parts, such as rails, bearings, runner blocks, lead screws, and ball nuts, should be cleaned every 40 hours of use. Using a lint-free rag, wipe down dirty surfaces, cleaning debris from the rails and the seals of the runner blocks and ball nuts. Clean and grease the rack and pinion regularly with a spray lithium grease or packing grease, as debris can build up in the teeth of the rack and wear it down.


Lubrication keeps your machine running, so it’s important to maintain your lubrication system. For rails with a manual lubrication system, find the grease zerks on the runner blocks and use a grease gun to add a few pumps of grease every 40 hours of use. Then run the machine back and forth to evenly distribute the grease. For automatic lubrication systems, make sure that the pump has an adequate amount of oil. (DMS provides a manufacturer label on each pump that ensures you use the correct type of oil.) It’s also a good idea to check routinely that the filter is clean of debris.

Automatic lubrication systems are typically PLC-controlled, based on distance traveled between linear axes. If the machine is lubricating too little and the rails and lead screws seem dry, decrease the amount of time set within the PLC parameter listed in the manual. Conversely, if the machine is lubricating too much, increase the value of that parameter so that it doesn’t lube as frequently.

As a daily task, check the oil-water separators on the incoming line, where water collects. Water is detrimental to the components of a machine, especially the spindle, causing rust over time. If you notice water collecting in your separators, you might want to consider getting an air dryer system.

To lubricate the retract cylinder, disconnect air from the machine and bleed the counterbalance tank. Remove the large airline from the top of the cylinder and put a few drops of air tool oil in the air line, then plug the line back in. The brass filter must also stay free of debris so that it can evacuate air affectively. You can remove this piece and blow air through the threaded side, if there is too much buildup, soak it in a solvent first. If the filter is in poor shape, we recommend that you replace it. Once this service is complete, hook air back up to the machine and re-pressurize.

Cleaning With Care

Some parts of a CNC machine are sensitive and should be cleaned with care. In the cooler, clean the grill with a gentle hand. Coolers are sensitive and can be damaged by a heavy tool like a screwdriver or the nozzle of a vacuum. A clumsy cleaning can alter the alignment of the shaft. If you need to vacuum the grill, make sure not to open it, which voids the warranty. In the electrical cabinet, the door should remain shut. This protects it from environmental factors that can shorten the lifetime of the machine. Carefully vacuum this area without touching the vacuum nozzle to any electrical components.

Spindles should also be clean and free of dust. Never blast compressed air into a spindle, ball nut seal, runner block, bearing, or electrical component because this can force debris inside that component. This is a good time for your lint-free rag. For automatic tool chain spindles, make sure to clean the tool holder receptacle, in addition to the mating taper where it connects to the spindle.

As always, it pays to be attentive to the unique needs of your machine. If you’re cutting abrasive material, that will introduce more wear and tear and make maintenance even more important. The better you know your machine, the better you’ll be able to care for it.

This may seem like a lot to remember. But you’ll be surprised how these cleaning tasks become second nature as you make them a part of your regular preventative maintenance. A little regular attention has exponential benefits.

If you would like to discuss cleaning your DMS machine or any other part of your CNC, don’t hesitate to reach out to our experts at: 855-266-5064 or

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