CNC Precision Machining Explained: Benefits & Practical Uses

“CNC Machining is more precise than conventional methods for creating bespoke components with higher dimensional accuracy, and consistency.”

Most contemporary industries use high precision cnc machining to manufacture custom parts that meet specific requirements. Accuracy is necessary for different uses, and that is why there is a need to produce parts that will have small limits of error. 

CNC precision machining is a process of manufacturing parts with the help of computer-controlled programs. It involves several methods and materials, and that is why its understanding should be as exhaustive as possible to achieve the best results in the implementation of projects. This guide focuses on the precision machining process, the various types of machine tools used, their advantages, and their uses. If you require precision machined parts from experts, please read on to get useful information.

What Is CNC Precision Machining?

Precision CNC machining

CNC Precision Machining means Computer Numerical Control Precision Machining. Precision machining is a process of cutting and shaping materials to create products through the removal of material under design specifications from CAD or CAM. This process is applied in various branches of production and can be used with various types of materials. 

CNC Machining Process 

Before even coming up with any product, there is the formulation of a very detailed 3D model using CAD or CAM. They assist in the guidance of the precision machining process to replicate the product. Machining is used to create parts for toys, medical equipment, cars, spaceships, and numerous other products. 

The CNC machining process includes cutting, milling, turning, and electrical discharge machining among others. Although the process is fully automated, skilled operators monitor the process to ensure that the products are of good quality. CAD is the process of designing a product while CAM is the process of using the design to produce manufacturing instructions. These instructions are then converted into a form that can be understood by a CNC machine by a post-processor. Machinists then use these instructions to load the CNC machine for production to begin. 

High Precision CNC Machining Tolerances

Tolerances are significant in high precision cnc machining. Although CNC precision machining tools are very accurate in their operations, they cannot offer a perfect match of the actual dimensions of the CAD blueprint. This is where tolerances come into play. Tolerance is described as the acceptable deviation from the set standard size of a part of the dimensional accuracy. The degree of tolerance is determined by the number of decimals present in the value of the tolerance, which gives the measure of tolerance.  

Types of Tolerance Measurements

Let’s talk about tolerance measurement ways in precision CNC Machining;

Unilateral Tolerance Measurement: The tolerance is allowed on only one side of the nominal value. For instance, if a shaft is to be 20mm in size, the most it can decrease in size is to accommodate a bearing. 

Limit Tolerances: The tolerance value is usually provided with an interval. For example, a shaft is required to have a nominal diameter of 15mm and tolerance limit of 15 + 0.05mm and – 0.05mm. 5mm is in the limit tolerance category. 

Bilateral Tolerances: Regarding deviation, bilateral tolerance is the variation from the nominal value and can be either positive or negative and is measured in terms of +/- value. For instance, a part with a measurement of 25mm and a tolerance of +/- 0.05mm can have a final measurement ranging from 24.95mm and 25.05mm. 

The tolerance to be used in each part must be determined properly. Not all parts need to be very close, but the structural elements that are in contact with other parts must be as close as possible to each other to remain apart. 

The cnc machining tolerance is crucial in precision machining because it helps in cost control and reduction of time taken in the manufacturing process. Thus, it is not a simple task to achieve the right tolerance level as it requires skill and time. The conventional CNC machine tolerances are usually of the order of 0.005 inches, however, some of the highly developed machines can be accurate to 0.002 inches. Therefore, the application of tolerances allows one to manufacture parts with the required accuracy and necessary functional characteristics.

Types of Precision CNC Machine Tools

Several ways are employed in precision CNC machining to guarantee that quality parts are produced. Each of the techniques requires the use of different equipment so that the results are accurate. Of the processes, some may require the use of a single CNC machine while others require the use of several machines to achieve the best results. 

1. CNC Milling Machines 

CNC milling machines are small batch cnc machining Processes, employed to cut or shape materials that are not moving by use of a revolving cutter. They are mainly used in manufacturing face-milled and peripheral-milled parts. Face milled features are smooth and flat and other small and narrow cavities and peripheral milled features are deep such as threads and slots. These machines are used in the production of square and rectangular components with features. 

2. The Turning Centers & Lathe Machines 

Turning is a micro machining operation in which the material is kept stationary and the cutting tools are mounted on a spindle that rotates. The cutting tools move parallel to the turning bar stock and remove material to the desired diameter and other characteristics. CNC Swiss lathes are a subcategory of CNC lathes that offer more support to the workpiece and hence produce parts of better accuracy. These machines are used to make external and internal dimensions such as bores, reamed holes, threads, and slots hence suitable for bolts, screws, shafts, etc. 

3. CNC Drilling Machines 

CNC precision drilling 

CNC drilling machines entail the use of a rotating drill to make circular holes in the material. These machines employ multi-point tools to reduce the chances of contact of chips on workpieces to further the machining of holes. Some of the drills that are used in CNC precision machining include spotting drills for making shallow holes, drill presses for special purposes, screw machine drills for holes that are not pilot drilled, chucking reamers for increasing the size of the holes, and peck drills for minimizing chip formation. 

4. Electrical Discharge Machines (EDM) 

EDM precision machining

EDM is a process where material is removed using electrical sparks that are controlled by the operator. Other related terms are spark eroding, spark machining, die sinking, or wire burning, and this process involves placing the workpiece in contact with an electrode wire. The machine expels electricity and this in turn generates heat that is used to melt the material. An electrolytic fluid cleans the molten material and provides the desired form. EDM is most effective in creating micro and small intricate hole slots and features at an angle on difficult materials. 

5. CNC Plasma Cutting Machines 

Precision CNC plasma cutting

CNC plasma cutting machines employ high-powered plasma torches to cut the materials, and the operation of the torch is automated by a computer. It is capable of generating a plasma of temperatures above 50,000 F to sinter the workpiece and make the cuts. These machines require materials that have electrical conductivity like steel, aluminum, stainless steel, copper, and brass. 

6. CNC Precision Grinding Machines 

CNC precision grinding 

In the cases where there is a requirement of surface finish then precision grinding machines like the CNC precision grinding machines are useful. These grinders are useful in achieving high levels of accuracy and a smooth surface on the material being worked on. In the past, CNC lathes and mills are typically used to create rough surfaces while precision grinders are used in the finishing of the surfaces. This ensures that the final product has the right surface roughness that is required for the product.

Applications of CNC Precision Machining

Accuracy cutting is commonly used in manufacturing since it is flexible, inexpensive, and time-efficient. This technology finds applications across various industries, including This technology is applied in various fields and some of them are: 

Medical Industry 

The medical field is an expanding sector and there is always the challenge of developing new equipment and producing in large quantities the existing ones. The major factor that is used in the production of products like orthotic devices, secure enclosures, implants, MRI machines, and research instruments is high accuracy. 

Automotive Industry 

Automakers always do, and they incorporate new features in the later models of the automobiles they manufacture. However, for these features to be incorporated into the manufacturing line, there is a development of prototypes of CNC machined parts to fit the specific requirements. Precision machining also manufactures parts for other means of transport including ships and transport trucks. 

Aerospace Industry 

The aerospace industry is very sensitive concerning the parts used in it since a small change might cause a lot of harm. Machining is very crucial in developing some of the parts of the aerospace vehicles such as the landing gear ports, bushing, manifolds, and airfoils. 

Military and Defense Industry 

As it is seen that different countries are developing new types of ammunition and defense systems, it is necessary to realize such concepts through CNC machining. This process develops components for aircraft, transportation, communication, and ammunition.  

Unique Benefits of High-Precision CNC Machining 

Utilizing high-precision CNC machines in manufacturing offers numerous advantages: The following benefits could be accorded to the use of high-precision CNC machines in manufacturing: 

Cost Efficiency 

CNC machining is relatively cheaper especially when it comes to the production of small to moderate quantities of the parts. It is cheaper at the initial stages than injection molding because the latter entails the use of costly molds. 

Increased Production Speed 

CNC machines work at a faster rate as compared to injection molding. CNC machining can make the parts in weeks while injection molding may take months to design and develop the mold.

Enhanced Performance and Dependability 

Some areas require very tight fits that cannot be achieved by the usual processes of material removal. CNC machining is accurate and it is easy to make many of the same parts at once, and all of them will be equally good. This repeatability ensures that there is quality in all the parts and this is very important in industries that call for high standards. 

Versatile Applications 

This type of machining is quite general and it can be applied to a wide variety of materials such as new-generation metals and plastics. This versatility helps various industries provide specific solutions to the market. The other advantage for developing a positive reputation among the clients for the automotive, aerospace, marine, and other industries is the ability to ensure the meeting of the tolerances with high accuracy. 

Consistent Part Quality 

CNC precision machining is very advantageous because variation is present in manual operations and is eliminated. The application of computer-enhanced software and low maintenance aspect guarantees that even complicated parts are produced to the necessary specifications that will satisfy the customers.   

Material Types Used in CNC Precision Machining

CNC precision machining is also flexible and fast when applied to various materials, although all of them are selected depending on the project. This process can be applied to metals and plastics with high accuracy and at the same time is fast and versatile. Here’s a closer look at the materials typically used: This is a brief look at some of the materials that are used: 

Metals 

CNC precision machining can be done on several metals and these are chosen depending on the characteristics and uses. The common metals include: 

• Aluminum: Aluminum is a lightweight material with high corrosion resistance and is used in aerospace, automobile, and consumer durables. This makes it possible to design structures that are complex and even complicated. 
• Steel: In construction, it is used in the construction of structural parts while in the manufacturing of machines, it is used because of its hardness. It is versatile, can be classified into several classes and its properties can be changed by heat treatment. 
• Stainless Steel: This metal cannot be corroded easily and cannot be stained easily hence it can be used in very harsh conditions and the medical and food industries. 
• Copper: Copper is an excellent conductor of both heat and electricity and this makes it be used in electric gadgets and heat exchange systems. It has good machinability which makes it easy for one to develop complex patterns. 
• Brass: Brass has good strength and appearance it is used for cosmetic and load-bearing applications such as valves, pipes, and car parts. 
• Bronze: It is very hard and does not rust; it is used in products that are to be used in areas of high humidity such as the coastal areas and in parts that are to be used under pressure and stress. 
• Titanium: Titanium is a very useful material because it is strong, light, heat, and corrosion-resistant, thus it is used in aviation and medicine. 

Plastics 

CNC precision machining also encompasses other forms of plastics with different characteristics for the kind in question. Key plastics include: 

• Acrylonitrile Butadiene Styrene (ABS): This material is valued because of the impact strength that makes it suitable for use in parts that are subjected to mechanical loads like car parts and homewares. 
• Polycarbonate (PC): It is strong and has good clarity and is thus used where the material has to be clear and strong like protective lids and optical lenses. 
• Poly(methyl methacrylate) (PMMA): Since PMMA is a clear material it is used as a glass substitute, has good light transmittance and weather resistance, and is used in sign and display industries. 
• Polyoxymethylene (POM): POM is also called acetal, this material has low friction and high stiffness and is used in gears and mechanical parts that require stiffness. 
• Polyamide (PA): Polyamide is also called nylon, it is used because of its strength, flexibility, abrasion, and chemical resistance therefore used in gears, bearings, and automobiles. 

The type of material to be used depends on the mechanical characteristics needed, the environment in which the product will be applied, and the cost of the material

Read more: Zinc Machining: Alloys, Processes, and Applications

Conclusion: The Value of Precision CNC Metal Machining

CNC machining with high precision is a technique of manufacturing parts with small tolerances and the benefits include high speed and low cost. This process, especially about the adoption of the Swiss-style automatic lathes has thus become a standard feature in contemporary manufacturing and machine shops. 

Swiss-style CNC machining is very fast for cutting features such as threads, holes, and steps and is nearly as precise as many of the new technologies such as 3D laser printing. This method does not only meet the dimensional demands but it commonly goes beyond them. 

Swiss machining can complete the machining of the workpiece to the required accuracy in a single pass with the help of the mentioned tools and techniques with the help of CNC. This capability can be spent less because the CNC automation is precise and consistent and will take less time compared to the manual way.

High Quality, Low-Cost Precision Machining with Maximum Value at Prolean Tech

If you are in a position where you are thinking of having to cut on your expenses, but at the same time you require the best precision machining services, then outsourcing with ProLeanTech is the best way to go. ProLeanTech has various precision machining services including 3-axis, 4-axis, and 5-axis CNC machining services. 

When you decide to get cnc machining service from ProLeanTech, it also means that you will not need to spend a lot of money on acquiring new CNC machinery. The company has installed modern equipment and experienced specialists to ensure that you get the best spare parts at affordable prices. Quality control is a different branch in ProLeanTech; thus, the team focuses on the components to meet the desired quality. This approach guarantees the high precision and reliability of each part that is manufactured making it the perfect solution for your precision machining needs.

FAQ’s

Q1. How precise can CNC machines be? 

CNC machines are very accurate and it is not very difficult to achieve very small accuracies. They are ideal for making parts with intricate shapes and tight tolerance levels, therefore ideal for precise uses. 

Q2. What are the acceptable levels of variation in CNC machining? 

In general, the tolerance in CNC machining is usually of the order of about ±0. 005 inches (0.   127 mm). The accuracy of CNC machining is up to ±0. 0. 0002 inches (0.  00508 millimeters) The thickness of the glass is 0. 

Q3. Which CNC machine is the most accurate? 

5-axis machines are considered to be the most accurate among all CNC machines. These machines have three straight movements, namely the X, Y, and Z movements, and two rotary movements, A and B, by which the parts can be oriented in almost any manner and at high speed and with a high degree of accuracy.