Computer numerical control (CNC) machines have become the standard in the machining industry. Their accuracy, speed, and ease of use make them indispensable tools. But despite these advantages, they are still not perfect. Quality control remains an important step in discovering and preventing defects, as many CNC machining shops have subpar quality control systems for their CNC equipment.
While CNC machines are far less likely to make mistakes than manual processes, mistakes still happen. When they do happen, they create bottlenecks, lead to waste, and hinder relationships with customers due to poor product quality if a CNC machining shop does not have a quality management system in place or is not aware of it when selecting suppliers. Conversely, an effective quality control program can improve the entire machining process by preventing these errors.
Learn more about ways manufacturers can improve their CNC quality control
Many people often think that quality inspection is the last step in the production process. While final inspections are necessary, quality control should also begin early. Finding errors after machining means it’s too late to recoup costs, but early inspections can prevent waste.
One of the most important steps a CNC machining factory can take to ensure quality from the beginning is to check the quality of the materials. Customers can check in detail from the samples they receive to see if the product is up to standard. While CNC machines can almost eliminate human error, they can produce defective products if they use low-quality or defective materials. Because even high-precision systems can produce inferior products if the materials used are not up to standard.
Therefore, in order to prevent these errors, factory employees must check the quality of raw materials before using them. Purchasing from trusted suppliers will help reduce many material-related problems, but machinists cannot take any risks. By looking for any cracks, weaknesses or other defects in the materials, workers can ensure that they are getting the most out of their CNC machines.
However, equipment issues are also a major concern because not all CNC machines are the same, and manufacturers should take this into account when dealing with CNC quality control. Using the wrong machine for a particular machining task can lead to more errors, so you must be selective about which orders need to be processed by which machines and choose the corresponding suppliers. The more complex the product or part, the more advanced its CNC machine should be.
Generally speaking, three-axis CNC machines are the most common type of mechanical parts, which are sufficient for simpler designs, but not more than that. For more complex parts or products, you should look for suppliers with four-axis or five-axis machines. The more axes a CNC machine has, the higher the accuracy of the machine, and it can perform more complex work without errors.
But this does not mean that a factory with four-axis or five-axis machines can perfectly control product quality. If the CNC machining shop cannot balance the work between different machines, reduce technical bottlenecks, and keep the overall operation efficient. Then it is not competent for complex machining. Then your company should send more complex designs to factories with higher axis counts for processing.
In addition, the factory’s machining operations should also include quality control steps during CNC machining. Equipment called machine tool probing systems are attached to CNC machines, which can check quality while the machine is working. This in-machine inspection allows the shop to deal with and correct problems as they occur, preventing errors in the final product. Probing procedures will not interrupt or interfere with the machining process, so adding probing procedures will not affect efficiency. They will automatically redirect the machine to correct problems detected in real time. By detecting and correcting errors early, they can prevent major errors, thereby reducing the number of defective or poor quality parts on the production line.
In addition to reducing scrap, in-machine inspection can also reduce quality control bottlenecks. Since machining time is the main cost driver in the field, it is crucial to ensure the efficiency of these operations. Tool probing systems prevent rework, reduce total machining time, and produce more consistent quality by minimizing interference with end-of-line quality inspections. Therefore, the internal quality management system of the factory with such an inspection system is relatively complete.
Therefore, when you want to choose the right CNC machining supplier, you should understand what conditions a factory with a good quality management system should have.
Does the CNC machining supplier use multiple quality control methods?
Just as CNC machining itself is not perfect, each quality inspection method has unique advantages and disadvantages. No one process can catch all errors that may occur. To address this, the factory should have the ability to use multiple CNC quality control methods to ensure that errors missed by one process are not passed on to the production line.
The order of quality control methods is as important as including multiple options. More specifically, manual inspection should always be the last stop, as should all processes that rely on automation. Automated inspection is usually very effective, but technical problems may occur and affect its accuracy. Putting manual inspection at the end can reveal these potential errors. Therefore, the factory’s quality management capabilities should be reflected in the workers. Only when the workers in the factory are quality-conscious, the production quality of this factory will not be poor.
One thing to remember here is that too many different methods may cause bottlenecks. The factory does not need to implement all possible quality control methods, but it should use multiple methods. Generally speaking, a material inspection before processing, an online inspection process during processing, and a manually driven post-processing inspection are sufficient. Therefore, although a factory cannot implement multiple quality control methods at the same time, it should understand and implement one or several of them.
Look for suppliers with relevant certifications
Not all CNC machining facilities perform their own CNC machining in-house, but CNC quality control is still important. To ensure a high-quality outsourced CNC operation, you should look for suppliers with the right certifications. These will vary by industry, but all suppliers should at least comply with ISO 9001, a general quality management certification.
Manufacturers in certain industries should also seek additional certifications. For example, ISO 13485 demonstrates compliance for medical-grade products, which is critical for manufacturers in the healthcare industry. Similarly, ISO 16949 applies to automotive parts, so manufacturers in the transportation industry should look for suppliers that meet that standard. These certifications don’t mean that suppliers will be 100% free from possible errors, but they can reduce risk. Strict standards are required to obtain these certifications, so it is a reliable guide to a quality production partner. Therefore, any factory outsourcing CNC processes should be aware of the relevant standards.
A reliable CNC quality control system is essential
An improved CNC quality control system will minimize waste and produce a better product. Not only will it help the factory save money, but it will also build a better reputation with customers. Poor quality management can have the opposite effect, making this area a critical focus for any CNC operation. By following these steps, machining processes can ensure their CNC quality control is as accurate and efficient as possible. They can then make the most of these exceptional machines and stand out from their competitors. CNC machining can be a wonderful resource, but only if the company using it adheres to high quality control standards. Elimold is one such company, so contact us if you have any questions.