Accuracy is essential to modern manufacturing; components that are off by even the smallest measurement can lead to assembly failures, lower product performance, and malfunctioning safety systems.
Precision CNC milling is a way that manufacturers can avoid these situations. It is the most commonly used machining method in US manufacturing today, and understanding how this process works can help you make informed decisions regarding your own production requirements.
What is CNC Milling?
CNC (computer numerical controlled) milling uses a rotating cutting tool to remove material from a workpiece based upon a digital (programmed) command. In milling, a computer-controlled machine performs precise, repeatable machining operations to produce parts with accurate (measured) dimensions.
Unlike manual machining, which relies on the skills of an operator and creates variability, CNC milling utilizes a developed program to control all machining actions. Each of the multiple parts produced during an operation will have the same dimensions.
Precision CNC cutting utilizes even tighter tolerances and produces superior (smoother) surface finishes than standard (CNC) milling.
How Does Precision CNC Milling Work?
The process begins by creating a CAD model, which is a digital blueprint for a piece of material to manufacture. After CAD creation, the model then needs to be converted into a CNC program using CAM software. This determines the tool paths needed to machine the part from raw material.
The CNC milling machine will then automatically execute the Tool paths. As each tool path is executed, the CNC machine can move simultaneously in multiple axes (X/Y/Z), allowing the milling machine to create very complex-shaped features such as angled surfaces, contoured profiles, pockets, slots, and precision holes.
During the complete process of machining, a CNC program will maintain a very consistent rate of speed, depth of cut, and feed rate. This consistent machining process makes CNC machining a very reliable method of manufacturing parts for applications that require extreme accuracy and cannot afford to take the risk of inaccurate manufacturing.
What Materials Can Be CNC Milled?
The ability of CNC milling machine services to offer a wide variety of materials is another advantage of this process. CNC milling process has a variety of engineered materials and metals that can be used as raw material, including:
• Aluminum Alloys
• Stainless Steel
• Titanium
• Hardened Tool Steel
• Copper and Brass
• Engineering Plastics (PEEK, Delrin)
The application will define what material is chosen; for example, aerospace components often require lightweight and strength, so either aluminum or titanium is typically used; on the other hand, oil and gas components would typically use stainless steel or high-strength alloys because they must endure high pressure and corrosive conditions.
An experienced CNC milling service provider will assist you in choosing the correct material for your part’s performance criteria.
What Tolerances Can Precision CNC Milling Achieve?
Tolerances refer to how much a part is allowed to deviate from its design specifications. A tighter tolerance means that a part will need to be manufactured more accurately. Thus, the manufacturing process utilizing CNC machines must be performed using more precise machinery and tools, as well as more precise inspection processes.
Precision CNC milling can consistently produce components with tolerances of +/-0.001 inches. However, in some cases, shops will produce parts with tolerances of +/-0.0005 inches or less for very high precision applications.
These tolerances are extremely important in industries such as aerospace, where having one defective part can result in catastrophic failure. The tolerances are also extremely important in industries such as semiconductor production, medical device manufacturing, and high-pressure instrumentation.
Why Is Precision CNC Milling Important?
The significance of precise CNC machining is based on the results of inaccurate parts. The following three principles detail why significant precision is a must when it comes to production.
· Consistency Throughout
If a single part has been manufactured to perfection, there is hope that its counterparts manufactured in 500-unit batches will present and function the same way as the original. Precision CNC machining offers you this consistency in every part produced—reducing potential for assembly problems, warranty claims, and failure due to lack of quality.
· Complex Part Geometries
Today’s components are manufactured in a way that simpler processes would not provide the desired results. Utilizing multi-axis CNC machining services enhances the ability to machine complex features with a single setup—reducing handling time and thereby reducing chances of introducing errors between cuts or setups.
· Waste Reduction
The precision machining of parts only removes material that is required for the part. Therefore, the accurate tool paths reduce scrap, reduce rework, and ultimately reduce the material cost during production.
· Faster Time to Market
Using a dependable CNC milling service allows you to take a digital design and convert it into finished parts much faster than most other manufacturing processes. This is an important factor when timing for product release relies on availability of parts.
What to Look for in a CNC Milling Service?
CNC milling service selection requires consideration beyond only looking for the appropriate machinery; instead, it will come down to skill and responsibility combined to deliver you the best possible outcome.
Ask all prospective shops if they utilize multi-axis machining centers and to what extent they have their own inspection equipment/coordinate measuring machines (CMMs). Find out about their tolerance capability, material experience, and any certifications they possess.
The ideal CNC milling service should provide production documentation including inspection reports and material certificates, thereby providing you with full traceability through your supply chain.
After-Sales Support from CNC Milling Machine Services
CNC machine service providers need to provide after-sales services like inspection records, reports of dimensionally correct parts, and a means to raise questions about the quality of parts after they have shipped.
Ask the machine service facilities you are considering working with how they handle problems that may arise after a purchase has been received. A machine service company that has a clear way of tracking all components through the time period of production, as well as having the necessary documentation to back its products, shows that the manufacturer is one that will provide continuing support over time.
How Mentco Manufacturing Delivers Precision CNC Milling Services?
Mentco Manufacturing provides precision CNC milling for challenging industry sectors in the US by leveraging cutting-edge multi-axis machining centers along with rigid AS9100/ISO certified processes.
Through the use of coordinate measuring machines (CMM) for both in-process and post-delivery inspections, each production component is traceable to the original raw material. Mentco provides CNC milling solutions for high-accuracy parts in several industries including aerospace, oil and gas, robotics, semiconductors and instrumentation.
Mentco works with you from the quote stage until your finished parts are delivered to ensure that all parts meet specifications and that your delivery deadline is met.
Conclusion
The basis of producing accurate, consistent, and repeatable parts is precision CNC milling. With precision CNC milling, US manufacturers are able to produce complex components within the tolerances required by the most exacting industries in the world.
If you need a prototype, a quick run of products, or an ongoing supply of high-precision pieces, you should work with a CNC milling service that has all of the right technological capabilities; certification and inspection processes; and support structures in place.
Mentco Manufacturing combines technology, certification, inspection, and support to create an integrated solution that businesses can use to produce parts with the level of precision that their industries require.
