When it comes to manufacturing precision components, CNC turning is one of the most important processes. This article will give you an introduction to CNC Turning so you can better understand this complex and versatile manufacturing process.
The CNC turning process utilizes a lathe or turning center to construct cylindrical shapes. It can also be used to perform operations like grooving, knurling, and threading.
What is CNC Turning?
CNC Turning is an intricate and detailed process based on one of the oldest machine tools in the world – the lathe. It uses computer-programmed machinery to replicate CAD models from various metals and plastics to create precision parts and components. It’s commonly used in manufacturing products for the automotive, medical, optical, aerospace, and power industries.
In the CNC turning process, a bar of raw material is held in a chuck and rotated while a tool feeds into it to remove material until it achieves the desired shape. It’s also known as “subtraction machining.” This process is incredibly versatile, allowing for many different types of finishes and a variety of shapes to be produced from the same starting piece of raw material.
The first step in the turning process is to create a CAD design using computer software. This is then converted into a program that can be read by the CNC machine and translated into its machine language. This is done to ensure the part will be created according to specifications. Once the CAD file is ready, it’s uploaded into the CNC turning machine to begin production.
Once the machine begins working on the workpiece, it’s important to ensure that the tool is properly aligned with the axis of rotation. If this isn’t the case, then the finished product may not have the intended accuracy or quality.
While the workpiece is rotating, the tooling can move on 1 or more axes to create various finishing details, such as cutting grooves, threading, and knurling. Threading, for example, cuts a helix into the workpiece that can be screwed into other pieces of metal or plastic.
Although CNC turning is very effective for creating precision parts and components, it’s not the best option for high-volume production. For these applications, other processes such as CNC milling and injection molding are more cost-effective. They can handle larger amounts of material and are capable of producing more complex geometries than turning. Despite these drawbacks, turning remains a useful and highly valuable manufacturing method. It’s especially ideal for projects that require a quick turnaround, allowing for faster and more accurate results than manual machining.
CNC Turning vs. Manual Turning
While both CNC turning and manual turning produce quality components, the process of creating these parts differs. For CNC turning, a CAD model is produced that can be translated into machine language that will guide the cutting tools and precisely duplicate the desired component. This is done by converting the CAD file to long lines of code, commonly known as G-code, which instructs the machine on how to perform each cut.
Once the program is created it is uploaded to the lathe and the cutting tool begins to remove material from the workpiece until it reaches the specified design dimensions. This is repeated until the component is completely fabricated. While this sounds easy, ensuring the accuracy of the machine requires expertise and experience.
A trained machinist can use the lathe to create a wide variety of shapes from any type of metal. This includes complex geometries, such as oblong or cylindrical parts, or more common, round parts like shafts and custom hollow tubing. The versatility of the turning machine also allows it to fabricate non-rotational shapes, such as hexagonal or square components.
However, the CNC version of this machining process offers many advantages over manual turning. For instance, it can save a significant amount of time and energy by eliminating the need for human intervention and reducing production times. This helps to reduce production costs and makes it possible for manufacturers to scale their operations more quickly without sacrificing quality.
The accuracy of CNC machining can also eliminate error rates and scrap in the production process. This not only improves efficiency but also ensures that the final product meets customer demands. It is also more energy-efficient than manual machining and can help manufacturers achieve environmental compliance.
A seasoned machine shop can use the computerized technology to deliver quality parts at an efficient rate. This translates to reduced lead times for customers and increased profitability. Although it may cost more to use a CNC machine, the initial investment is often offset by the improved productivity and quality of the finished product. The ability to accurately duplicate parts across multiple runs can further increase profitability.
CNC Turning vs. Milling
While CNC milling and turning are both subtractive machining processes, they differ in how they approach the workpiece. In CNC turning, a bar of raw material is held in a chuck and rotated while the cutting tool removes excess material to create the desired shape. Milling, on the other hand, uses a rotating cutter to cut into a stationary piece of material to produce a finished product.
Both processes require a machine that can read a computer program to operate. The program, which is a series of numbers and letters that correspond to tools, cuts, and other specifications for the part, is fed into a programable CNC lathe or milling machine by an operator. This machine then follows the instructions to make the necessary changes and adjustments.
CNC turning works with many different materials, including metals (such as carbon steel, alloy steel, cast iron, and stainless steel), wood, plastics, and composites. It can also perform a variety of operations, such as threading, knurling, and boring. However, it is best known for its ability to turn complex geometries, which can include conical and oblong shapes.
It can be difficult to determine which manufacturing process is right for a specific project. In many cases, it comes down to the cost and lead time of the production run. Generally speaking, CNC turning is cheaper than milling because it requires fewer tools and can be performed in less time. However, there are situations where milling may be more appropriate, depending on the final product’s required geometry and dimensions.
CNC Turning vs. 3D Printing
Unlike 3D printing, which relies on layering and can have limitations when working with curves, CNC turning is capable of producing finished products that have much tighter tolerances. Parts made from this process are also less likely to bend or warp and have a more polished look than those produced by 3D printers. This manufacturing method is also compatible with a greater range of materials and can be used to create complex geometries that are not feasible through other processes, such as injection molding.
The process of CNC turning involves using a lathe to shape a bar of raw material into a desired contour. The computer sends instructions to the machine, which translates them into movements that allow the tool to remove bits of material from the surface of the workpiece until it has the desired shape. It is possible to produce a wide variety of shapes with this process, including conical and oblong components, though it is most often used for axisymmetric parts like shafts. Many machines across industries rely on these types of precision shafts to operate properly.
A CNC turning machine can perform tasks at a much faster rate than a manual lathe, reducing the amount of time it takes to finish a production run. This makes it an ideal option for high-volume manufacturing, as well as for companies that need to turn out prototypes quickly. This machining method is also more accurate than other methods and eliminates the chance of human error.
As an alternative to 3D printing, CNC machining is a great choice for companies looking for a more versatile and reliable production process. It is compatible with a broad range of materials, has a lower setup cost, and can be completed in half the time it takes for some other production methods. This allows companies to make the most of their resources and deliver results that meet or exceed customer expectations.
Another benefit of CNC machining is that it offers an open architecture, which means that users can source their tools and materials from different suppliers rather than having to buy them from the same manufacturer. This is an advantage over 3D printing, which typically requires that you purchase everything from the same company.
If you’re interested in purchasing a CNC Turning machine, browse our extensive inventory of machines and parts. Contact us at Tramar Industries and we’ll help you find the right machine for the job.