Today's smartphones have transitioned from plastic back covers to thin and light metal bodies. While the sleek design can attract consumers, the manufacturing process for phone case parts suppliers is much more difficult because the cutting and machining of the case requires extremely high precision. Even the slightest deviation can cause the workpiece to be scrapped, resulting in a loss of profits.
To improve CNC machining yield, mobile phone case manufacturers are often forced to frequently change cutting tools to ensure that CNC machines maintain normal production cycles. However, this leads to increased consumable costs, which also affects profits. In addition, mobile phone case manufacturers attach great importance to uptime, fearing that a sudden failure of the CNC cutting machine will trigger a negative chain reaction such as decreased production capacity and delivery delays, damaging customer satisfaction and reputation. Therefore, they allocate manpower to conduct regular inspections and outsource to provide second-line maintenance support. However, these methods are all passive measures and are difficult to effectively handle in the first instance when abnormalities occur.
Mobile phone casings are one example of CNC machine tool applications. CNC cutting is widely used in various processing and manufacturing processes, and various suppliers face similar battles to protect their profits.
Hsu Chang-yi, manager of the Measurement and Automation Products Division at ADLINK Technology, believes that whether the goal is to improve machining accuracy or increase uptime, the fundamental solution is to implement monitoring during the cutting process, especially vibration monitoring. This is because if the machine's vibration value rises beyond the reasonable range due to imbalance, resonance, or misalignment, it can easily affect the machine's operation and lead to malfunctions and downtime.
PC-based monitoring solutions outperform PLC solutions for capturing subtle vibration signals.
If CNC machining machines can be given intelligence and have a built-in vibration monitoring mechanism that operates around the clock, they can diagnose the machine's health status at any time. Instead of waiting for the final product to be produced and judging the cause of the abnormality afterward, they can detect the unusual state of the machining machine in real time through preventive detection and take corresponding measures, including optimizing and adjusting machining parameters (such as changing the spindle speed) or replacing tools, etc., to immediately solve small deviations and avoid causing major disasters in the future.
It cannot be denied that the monitoring of cutting vibration of CNC machining is not a new issue that has just emerged. In the past, there have been some PLC solutions that prioritize simplicity and convenience, claiming that they can quickly produce results as soon as they are connected to the CNC machine. Therefore, it is inevitable that some people are curious: since there is a PLC to assist in the monitoring of cutting vibration, why is it necessary to use a PC-based monitoring solution?
As the saying goes, the devil is in the details. Some subtle vibration signals or high-frequency signals can reflect certain facts. It may be that the connection mechanism is starting to become unbalanced, the ball bearings of the rotating spindle are breaking and affecting the transmission power, or the fasteners are becoming loose. All of these mean that the CNC machining machine is starting to "get sick," and the symptoms are not the same depending on the characteristics of the machine. These subtle and variable signs are actually not easy to collect with PLC solutions, which have characteristics such as low sampling rate, limited bandwidth support, and fixed algorithms. If a CNC monitoring solution can capture subtle changes and help users quickly grasp the key factors that may lead to reduced accuracy or decreased production capacity, they can respond in a timely manner.
In light of this, ADLINK has launched a cutting vibration monitoring solution called MCM-100. It boasts the ability to perform 24-hour uninterrupted data acquisition and vibration measurement for rotating machinery and equipment with high precision and high sampling rate. It integrates data acquisition, vibration analysis and calculation, and network access into one function, helping CNC machine tool users to smoothly solve various challenges faced by traditional cutting processes and empowering CNC machine tools with intelligence in the easiest and most burden-free way.
High-precision monitoring enables optimal preventative maintenance.
Xu Changyi explained that, generally speaking, there are three types of monitoring scenarios that CNC machining centers would like to establish. The first is "Spindle Vibration Detection," which refers to monitoring the vibration of the spindle during cutting. This is done by directly measuring the RMS value of the time domain signal. If the value exceeds the threshold, the speed is reduced or the machine is stopped. The second is "Bearing Quality Diagnostic," which refers to diagnosing the health of the bearings. This is done when the CNC is not performing cutting and is only idling at high speed. The third is "Spindle Collision Detection," which is used to detect spindle collisions. When the vibration waveform meets certain preset conditions, it is analyzed that a collision has occurred, and the spindle movement is immediately stopped.
The first and second scenarios mentioned above are closely related to the accuracy and bandwidth range of the vibration signal. PLC solutions can only collect very little information, making it difficult to assist users in establishing response strategies. In contrast, the MCM-100 not only has a high resolution of 24 bits (generally falling within the 12 or 16-bit range), but can also capture high-frequency signals with a sampling rate of up to 128 KS/s (generally only supporting 20 KS/s or even lower), providing users with more vibration analysis materials.
New Business Opportunities for CNC Machining Equipment Manufacturers
On the other hand, cutting vibration monitoring solutions can also create new business opportunities for CNC machining equipment manufacturers. As CNC machining equipment suppliers gain access to a large amount of vibration information, and with the integration of big data analysis, they can gain a more thorough understanding of the correlation between signal changes and machine malfunctions. CNC machining equipment manufacturers can make good use of their accumulated knowledge assets to generate value-added services, and even adjust their business models accordingly, shifting from selling equipment outright to selling machine operating hours, thus establishing long-term stable revenue.
ADLINK Technology, a leading manufacturer of PC-based cutting vibration monitoring solutions, stated that its vibration monitoring solutions have entered the implementation stage and are being adopted by various well-known CNC machine tool manufacturers. The demand for these solutions increased significantly in 2017, demonstrating that both CNC machining manufacturers and CNC machine tool manufacturers have an increasingly strong need for CNC cutting vibration monitoring solutions.
