Computer numerical control (CNC) machine tools have revolutionized the manufacturing industry by improving product quality, operational efficiency, and reliability. This technology is so popular that the global CNC machine tools market is expected to reach $140.78 billion by 2028, growing at a CAGR of 7.1%. As with any other technology, these manufacturing powerhouses experience breakdowns and other problems. These relatively minor problems can have far-reaching consequences if the right knowledge is lacking.
Common problems with CNC machines range from stuck parts to overheating. These problems require a proactive approach to prevent outcomes such as spindle failure, which can bring operations to a standstill and cause significant revenue loss. Identifying and resolving problems before they occur and as soon as they occur is often the most efficient and cost-effective way to improve machining uptime.
7 Common Problems with CNC Machines
Common problems with CNC machine tools can have serious consequences. Errors may seem trivial, but if not caught in time, they can cause serious damage to tools and machine tools. These problems can shorten the life of the machine and affect productivity, resulting in replacement costs or significant downtime. Over time, they can lead to complete failure.
Identifying and resolving common machine tool problems can extend the life of the machine. Predictive and proactive maintenance also reduces downtime and keeps our machining tools running optimally, which increases overall efficiency.
The most common CNC machine tool problems include
Code Errors
Computer-driven machines rely on complex code, and programming is one of the most common errors machine operators encounter. These errors can be caused by entering incorrect variables into a program, setting them up incorrectly, or a lack of understanding of the different G and M computer codes.
These problems can be difficult to detect, especially if the employee is inexperienced. Many will immediately look for the machine, ignoring the possibility that the problem may be coming from the computer. Wasted time, materials and machine damage can lead to costly and slow operations.
Lack of Maintenance
CNC machines consist of many moving mechanical systems that must work to extremely tight tolerances to ensure product quality. The slightest error, wear or debris can seriously affect machine performance, causing jams or permanent damage. Over time, dirt and debris can build up and small errors can become more serious, eventually leading to machine failure.
Material movement during cutting, overheating and noise are common signs of problems with CNC machines. The most common signs of overdue maintenance include minor machine errors such as substandard or barely conforming surfaces.
Vibration or Humming
Vibration during operation can shorten the life of a tool, affecting its durability and long-term functionality. The efficiency and cost-effectiveness of the machine can be compromised due to chatter and vibration. If an operator notices any unusual noise or chatter, the source of the vibration should be identified and the necessary steps taken to resolve the problem.
However, machine vibration is often present long before it is noticeable to the human ear, and modern maintenance practices include regular monitoring of vibration and ultrasonic frequencies to detect minor performance deficiencies.
Chuck Fixture Clamping Problems
Inattention when clamping workpieces on the machine is another common mistake in CNC machining. Incorrect clamping can lead to problems such as misalignment, chatter, or distortion that can damage the machine or the workpiece. If the chuck does not hold the workpiece securely, it may need to be replaced. This problem can be more serious than damaged workpieces or tools. Improper clamping of machine parts can cause accidents and injure the operator, compromising the safety of the entire operation.
Incompatible Power Supplies
If the operator notices a problem with the machine's performance, there may be a problem with the power supply. The power supply must always provide the correct voltage to the inputs. The outputs must also work correctly to ensure that the machine is receiving enough power. Underpowered machines will take longer to work to achieve the same results, leading to tool failure or workpiece damage. Too much power can damage the machine or even lead to complete failure.
Improper tools or settings
Incorrect cutting tools can affect the quality of the material being processed. Watch for cut marks, rough edges or burn marks on the edges and corners of the material. Repeated use of incorrect tools or settings can lead to severe tool wear. Dulled tools and incorrect speed ratios can also result in rough material surfaces.
Overheating
Overheating is a common problem with high volume and long machining times. Overheating of the machine spindle is usually caused by uncleanliness of the machine and lack of proper airflow. Ambient temperatures often cause the machine to overheat, which affects the quality of the work, the tool and the machine. Typical CNC machine tools should maintain a stable temperature range to prevent undesirable consequences.
How to Avoid Common Machine Tool Problems
Although difficulties are sometimes unavoidable when operating complex machinery, supervisors can take specific steps to minimize unnecessary damage and breakdowns. A preventative approach can save time and money by avoiding unnecessary downtime, repairs and replacements. Taking the following steps can minimize the impact of common errors and preserve the life of your machines:
Prioritize operator training: Human error is common in production, whether it's choosing the wrong tool or entering data incorrectly. Ensure that operators are provided with extensive training and user manuals, and have experienced operators guide them until they are familiar with the relevant settings and protocols.
Develop a preventative maintenance program: CNC machines require regular cleaning and maintenance. Develop a detailed maintenance program and ensure that the team documents any repairs so that the business has a comprehensive record of problems with each machine. Operators should check the machine regularly to ensure coolant levels are adequate and to recognize signs of wear and tear.
Perform vibration analysis: Vibration analysis allows machine maintenance specialists to monitor machine vibration data and detect potential problems. It can detect bearing failures, bent shafts, misalignment, loose components and more. If an operator is concerned about vibration, consult a professional to help identify the root cause.
Monitor the environment: Environmental factors are an important part of efficient CNC machine tool operation. Monitor temperature, humidity, noise and power fluctuations to ensure the machine has an efficient operating environment.
Calibrate the machine: Regular calibration keeps your machine accurate and reliable. Follow the manufacturer's guidelines and have an expert check the machine regularly to fix small problems before they become big ones.
Machine tool problems and operator error can be costly to an operation. Working with an experienced and trusted machine tool expert can minimize these problems with comprehensive after-sales service and trusted guidance on proper setup, programming and maintenance. These professionals can also advise on whether to repair or replace equipment, thereby increasing uptime and machine life.
Avoid Common CNC Machine Tool Problems with Monument
Factors ranging from programming errors to overheating and vibration can cause simple machining problems to escalate into more challenging situations. Keeping spindles, slides, milling heads and bearings in top condition is critical to improving overall productivity and performance.
As the world's largest independent machine tool component rebuilder, we have the skills and experience to build and repair CNC spindles.
We understand the importance of balancing quality and efficiency, which is why we offer precision spindle inspection and repair services to ensure that your machine tool remains at peak performance. Contact us today to learn more about how we can restore your spindle to OEM specifications or better!
