What is CNC Turning?

CNC machining has quickly taken over the manufacturing industry in recent years because it is so precise and can be used over and over again. There are many different types of CNC technology available today, so understanding the basics of CNC machining helps to differentiate between them. CNC turning is one of these new tools.

CNC turning involves the use of a non-rotating cutting tool on a turning center or lathe to remove material from a rotating, rigid workpiece. Depending on the type of turning action, CNC turning can create parts of different sizes and shapes.

The concept may seem simple, but high-quality CNC turning is complex. Let’s say you want to know what this production process is and how to get the best results. This guide will tell you everything you need to know about CNC turning.

What Is CNC Turning?

Similar to a lathe, CNC turning is a very precise and fast method of removing material from a workpiece. It involves pressing a cutting tool against a rotating workpiece to remove material and machine it in the desired manner.

The center of rotation (also known as the lathe) remains stationary while the raw material rotates rapidly. A dual CNC lathe moves the workpiece along two axes, and a single-point cutting tool helps shape the material. A computer program helps run the lathe or turning center, ensuring that very precise parts are made.If you want to know more about how to choose the right material for CNC turning. You can refer to our CNC turning material selection guide.

Many people confuse CNC turning with milling, but they are two different processes. In CNC milling and most other subtractive processes, the workpiece is usually clamped to the bed while a tool is moved to cut it. CNC turning, on the other hand, works in reverse, with the workpiece rotating while the cutting edge remains stationary.

What Shapes of Parts Require CNC Turning?

CNC turning can produce a wide range of shapes, depending on the type of turning process used. Lathes and turning centers have many capabilities. Examples include straight line turning, taper turning, external groove turning, thread turning, knurling turning, boring, and drilling.

For the most part, lathes can only perform simple turning tasks. Examples include straight turning, external grooving, threading, and drilling operations. Since turning centers have a turret, they can perform all the tasks that a lathe can do. In addition, turning can perform more complex tasks such as drilling out rotating shafts.

CNC turning can machine many shapes that have axial symmetry. Examples include cones, cylinders, disks, or a mixture of these shapes. Some turning centers can even perform polygonal turning, which means they can use special rotary tools to create shapes, such as hexagons, along a line of rotation.

What Is the Difference Between CNC Turning and CNC Milling?

If you want to choose the right CNC machining process for your project, it’s important to understand the difference between CNC turning and CNC milling. Both methods have their own strengths and capabilities that can have a big impact on the end result of a machined part.

Let’s take a look at the key differences between CNC turning and CNC milling and provide you with a rule of thumb. This can help you choose the right machining method.

Workpiece Motion: The Core Difference

The way the workpiece moves is the main difference between CNC turning and CNC milling. In CNC turning, the cutting tool remains motionless while the workpiece rotates. By this method, axially aligned parts can be machined with high precision and smooth surfaces.

In CNC milling, the workpiece remains motionless while the cutting tool moves in multiple directions. By this method, parts with complex shapes and fine features can be machined. And this is turning into a process that can not be realized.

There Are a Variety of Options for Part Geometry

CNC turning and CNC milling is very different in terms of flexibility, especially in terms of part shape. CNC milling can process more shapes than CNC turning. CNC turning, on the other hand, is best suited for machining parts with axial symmetry, such as cylinders, cones, and disks.

CNC milling is the best method for making parts with complex patterns. Because it can make parts with complex shapes, grooves, slots, and three-dimensional features.

How to Get Perfect Surface Finish

Both CNC turning and CNC milling can achieve perfect surface finish, but they are not always the same. In CNC turning, the workpiece is constantly being machined. This usually results in a smoother, more polished surface of the workpiece.

To help you evaluate surface quality, we provide a surface finish chart to make it easy for you to review and select from different finishes to ensure the finished product meets your requirements.

In CNC milling, on the other hand, cutter marks may be left on the workpiece, which usually depends on the cutting tool and milling technique. However, CNC cutting can also result in a good surface finish if the right tools and settings are used.

Tools and Settings: Cost and Time Factors to Consider

In most cases, CNC turning is superior in terms of tooling and setup. Setup usually takes less time and is easier since only a few tools are required. On the other hand, CNC milling may require more than one tool to create the complex shapes required. This can make setup take longer and cost more.

This is an important issue to consider when looking for the best and most cost-effective way to manufacture parts.

Benefits Of CNC Turning

There are many advantages of CNC turning, such as the following:

Accuracy

Using CAD or CAM files, CNC lathes allow for precise measurements to avoid human error. Whether it’s making a prototype or an entire production cycle, experts can use state-of-the-art machines to achieve incredibly high levels of accuracy. Every cut is precise because the machine is designed that way. In other words, the last piece cut is the same as the first.

Flexibility

Turning centers come in different sizes and can therefore be used for a variety of tasks. The work on this machine is already set up, so it is very easy to adjust. The operator only has to make the necessary modifications to the programming in the CAM software in order to complete the machining of the part or to manufacture other parts altogether. Therefore, if you need a large number of different parts, you can rely on the same precision CNC machining services company.

Safety

In order to ensure everyone’s safety, companies that manufacture items follow strict safety rules and laws. Automatic lathes mean that there is less work to be done, as the operator’s only job is to keep an eye on the machine. Similarly, the body of the lathe has fully or semi-enclosed safety features that prevent particles from splashing from the items being processed, as well as preventing injuries to staff.

Faster Speeds

On CNC lathes and turning centers, there is a lower chance of error when the work is done according to a program. This type of machine allows for faster production without lowering the level of the end result. Finally, you can get the parts you need faster compared to other options.

How Does CNC Turning Work?

How CNC turning works can be difficult to understand. But we’re going to simplify the process and walk you step-by-step through the entire process, from planning to production.

Here are the main steps of CNC turning:

Step 1: Converting CAD Files To CNC Programs

The first step is to convert the CAD file into CNC machine language. This does not require any complex code. You should already have some 2D drawings of your idea. You will then need to document these drawings electronically using software such as AutoCAD or SolidWorks.

It is possible to convert electronic drawings from CAD file format to CAM file format. You can also send drawings in CAM format using the software tools mentioned earlier. The manufacturing engineer can then use these tools to check if the part can be manufactured.

Step 2: Prepare The CNC Machine

The next step is machine setup. Although most of the work is done by machine automation, an operator is still needed. To get the CNC lathe ready, you should do the following:

• Make sure the power is turned off. Using a CNC machine can be very dangerous. Extra care is therefore required and the power switch must be checked before operation.
• Secure the workpiece to the block. Thanks to the chuck, the part will stay in place while the machine is turning. If it is not loaded correctly, it may be dangerous and the part may not be the right size.
• Load the tool turret. different tools are used when turning, so you need to make sure that you choose the right tool for the desired finish. A turret will help you hold as many tools as possible at the same time while you work.
• Ensure proper calibration. To do the job correctly, you must set up the tool and workpiece in the right way.
• Upload the CNC program. Entering the CNC code into the machine is the last thing you need to do before the job begins.

At this point, you need to keep two things in mind. The first is the turning speed, which is how fast the item is turning. The second factor is the feed, which is the speed of the cutting tool as it moves along the rotating workpiece.

These numbers must be determined by a fabrication professional, as incorrect guesses can alter the end result. Additionally, incorrect estimates for certain materials can result in uneven surfaces or damage that cannot be repaired.

That said, to “rough out” a shape, you can maintain low turning speeds and high feed rates. On the other hand, high turning speeds and low feed rates are best suited for parts that require a smooth finish with very tight tolerances.

Step 3: Make The CNC Turned Part

The final step is to make the part you want. You can choose different turning processes depending on what you want to achieve. The number of turns also depends on the complexity of the part. The cycle time calculator will tell you how long the part has been machined in total, which is important for calculating the cost.

In most cases, the cycle time of the variation includes:

• Load time. This is part of the setup, but a cycle may require a different way to put the part on the machine.
• Cutting time. This is the time it takes to cut the workpiece. Cutting time is affected by feed rate and depth of cut.
• Idle time. Any work that does not involve cutting is called idle work. For example, changing the way the tool is moved, the way the turning center is set up, etc.

The effect produced by the manufacturing method depends on the raw material used. Metal parts have a smoother surface and work differently than plastic parts.

Types Of CNC Turning Machining

CNC turning has different types of lathe tools. As a result, you can perform a variety of operations on a single workpiece. There are two types of these operations: internal and external. External operations can change the outer diameter of the workpiece. Internal operations, on the other hand, can change the internal width.

Each operation is unique because the cutting tool and the path to remove the material are different. Let’s take a look at how they work.

Turning Specific Operations (External)

 Turning

In this step, a single-point turning tool moves along the side of the workpiece to remove material and machine different shapes. It can machine shapes such as tapers, chamfers, steps, and contours. These features are usually machined with a small radial depth of cut and are machined several times to achieve the final width.

By gradually decreasing or increasing the width of a cylindrical workpiece, taper turning can machine a surface that resembles a taper.

Hard Turning

Materials with a Rockwell C hardness exceeding 45 can be turned by this method. It is important to heat treat the workpiece before starting this process. The purpose of hard turning is to reduce or eliminate the need for grinding. When used to remove blanks, it is as effective as rough grinding. However, for tasks where size and shape are critical, hard turning may not be as effective.

Facing

In this step, a single-point turning tool is moved outward along the end of the workpiece. In this way, small layers of material are removed, leaving a flat, smooth surface. The depth of the surface is usually very small and can be accomplished in just one pass.

Grooving

In this process, the single-point turning tool also moves radially to the side of the workpiece. In this way, it creates a groove that is the same width as the cutting tool. You can also make multiple cuts to create a line wider than the tool. In addition, some manufacturers use unique tools to create grooves of different shapes.

Separation

The cutting tool cuts radially into the side of the workpiece, just like a groove. A single-point tool cuts all the way to the center or inner rim of the workpiece. Thus, it cuts a piece of raw material.

Non-Specific Operations (Internal)

Boring Tools

Boring tools go inside the workpiece being machined and cut along the inside surface to produce shapes such as steps, curves, tapers, and chamfers. The boring head is adjustable and you can set the tool to the desired cutting width.

After drilling holes in the workpiece, it may be helpful to perform some boring activities. This will help to obtain more accurate dimensions.

Drilling

Using a regular drill bit, drilling removes material from the inside of the workpiece. The turret or tailstock of the turning center holds these drills in place.

Threading

For this job, a single-point threading tool with a 60-degree angle at the tip is used. This tool moves axially along the side of the workpiece and cuts threads on the outside of the workpiece. The machinist can cut threads to a specific length, but some threads may require multiple cuts.

Knurling

In this process, a special knurling tool is used to cut a serrated design on the surface of the workpiece. This design can be used to improve appearance or as a handle.

Reaming

In the sizing operation, a small amount of metal is removed from a punched hole. It can be helpful to make holes of the same size internally. For example, it is easy to read the exact size when drilling a 6 mm hole with a 5.98 mm drill bit.

Types Of CNC Lathes

There are four main types of CNC lathes you can use for your project. They include:

Horizontal Turning Centers

This group of machines is sealed for drilling and milling. Turning centers have the cutting tool placed above the rotating workpiece and the spindle placed horizontally. As with machining, the cutting tool cuts on the material, and chips fall to the floor. The chips sink into the bed for easy removal.

Vertical Turning Centers

Horizontal turning centers and CNC milling machines are all part of a vertical turning center. Due to the way they are designed, the rotary chuck sits flat on the floor. This allows large workpieces to be machined at slower revolutions per minute (RPM). In this case, the tool launcher is accessed from the side. There are also vertical turning centers that are upside down, which means the spindle and chuck are not in the right position.

Horizontal Lathes

Horizontal lathes are identical in all respects to ordinary lathes. The only difference is that they are run by a computer program. In addition, their main functions are turning and boring.

Vertical Lathe

Vertical lathes hold the workpiece from the bottom before rotating it, while horizontal lathes hold the workpiece from the top. This is a good choice for machine shops that don’t have a lot of space. Additionally, vertical lathes are the best choice when machining large items.

Want The Best In CNC Turning?

You now know what CNC turning is and its advantages. Nonetheless, you can only get these advantages if you hire a trusted manufacturing partner for CNC Turning. In this case, Yonglihao Machinery is the best choice for all your CNC Turning needs.

We have state-of-the-art turning tools and new technologies to help improve your custom machining experience. We also ensure that you get high-quality parts that meet your needs through strict quality control and quality assurance, as well as the knowledge and skills of our experts.

To Summarize

CNC turning is an important part of manufacturing because of its ability to accurately create many different parts. Its adaptability and manufacturing capabilities ensure that the same results are obtained on a large scale.

This article talks about many aspects of CNC turning, such as its unique benefits. For your work, this will help you make the best choice. However, if you would like more specialized help with this manufacturing process, call Yonglihao Machinery today.