Two Reasons Why Your CNC Machine Will Break Down

Jun 26, 2017 | Machinery

The very nature of a CNC machine suggests an environment that can be harmful to itself and cause its own demise: Lots of lubricants and cutting fluids, oil, metal shavings, dirt and dust, etc. are everywhere. Sound extreme? Well, it is, and a recent visit to a manufacturing facility confirmed a long known fact: If not properly maintained, CNC and other machinery will fail sooner than later. To those that work in and around manufacturing machinery, it is known that the internal parts of the CNC, the electronic controls and servo motors, are the first thing to fail. And the 2 things that contribute the most are heat and contamination. I’m going to show you(with real pictures too!) how both work together to sabotage your machinery, especially the CNC machine. Let’s start with heat. When we were on the floor of the production facility, it was 137 degrees. Inside the particular cutting machine that we observed it was well over that temperature. High heat wreaks havoc on a machines controls, such as amplifiers, controllers, drives, power supplies, monitors and HMI’s, PLC’s, etc. High humidity caused by fluids, also harms circuit boards and causes them to fail. Each cabinet on a CNC machine holds the controls and can get upwards of 150 degrees. To help combat this high heat, all cabinets are outfitted with AC units. The AC units have filters on the intake and over time, get clogged by, you guessed it, contaminates. Contaminates from the cutting or machining process, such as cutting fluid and hydraulic fluid, become airborne and clogs the filters on the AC units. The AC units then start over-working and not too soon after seize up or fail. This increases the temperature in the cabinets until the controls begin to fail. It also can get directly into the machines’ cabinet if not properly sealed or maintained. Contamination not only fouls up amplifiers, drives, HMI/Monitors, and any electronics in concert with servo motors, but also defiles the cabinets AC units that keep the whole system cool. This creates the vicious cycle! Also, if you have contaminates in your pump systems, it will eat the seals on your pumps, which are pumping coolant into your process to keep the cutting tools and product from getting too hot. The motor connected to the pump has seals that are eaten by contamination and the motor begins to work harder and failure becomes eminent. Preventative maintenance plays a huge role in keeping your CNC machine running longer and more efficient. Regular maintenance on all AC units by thoroughly cleaning or replacing the filters clogged by by way of contamination will, in turn, keep your cabinets cooler, longer. Making sure the cabinets are sealed correctly will keep the controls cleaner and less likely to fail. Routine maintenance needs to be performed on all of these units.


  • Make sure all of your fans (internal, external, circulator, and chiller) are in good operating condition.
  • Be sure all heat sinks are clean of debris and contamination.
  • Check all air intakes and discharges to make sure filters are clean and airflow is not obstructed.