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You probably know what CNC turning is and how it works, but let’s remember a few more basics to fully understand its operation and get the most out of this machine. Want to start your adventure with CNC? Familiarize yourself with the elementary knowledge of the construction of this type of machine. Read our guide which discusses the most important elements. Welcome!

How does the CNC lathe work? 

On a CNC lathe, the geometry of the workpiece is shaped by removing material. During turning, the workpiece material rotates around a hypothetical axis mounted in a chuck. This axis is the Z-axis and contains the primary motion, a rotary motion. The cutting tool performs a secondary motion, feed. When the tool contacts the surface of the workpiece, the material is removed, which is how cutting is done on a lathe. In practice, it looks like this: the cutting tool is on one side of the workpiece diameter on the X-axis, and the diameter of the workpiece surface is formed around the Z-axis. The cutting tool can move longitudinally or transversely. It is worth noting that workpieces can have different geometries. We point out that the geometry of the workpiece depends on the combination of the two axes (rotation and feed) and the cutting tool used. In turn, the cutting tool to be used depends on the type of surface to be produced and the type of turning operation.

What are 2-axis and 3-axis lathes?

If you read basic material on CNC machine building, you will surely find information about 2-axis and 3-axis lathes. The difference between them is the number of axes – as the name suggests.

  • On a 2-axis lathe, machining takes place on 2 axes.
  • On a 3-axis lathe, machining takes place on 3 axes.


Three-spindle lathes are said to offer more options. But let’s explain it a little better. What we have said so far applies to 2-axis lathes: X and Z; it programs both axes. The tool then moves linearly as the part rotates around its axis. The linear motion of the tool can be along or perpendicular to the Z-axis of the part. Three-axis lathes include an additional axis that can be rotated. This is called the C axis. You can certainly expect more from a 3-axis lathe. With a 3-axis lathe, some milling operations can be operated and programmed. More specifically, you can change the position of the tool around the axis of rotation of the part and make slots, holes, and several peripheral features as per the drawing requirements.

Why are CNC lathes so popular? 

The lathe is one of the oldest machines ever invented. However, modern lathes have undergone significant modernization to incorporate several technological advancements. Lathes have evolved alongside other types of machine tools and are now widely used in industry. But why has the lathe gained the trust of the industry and such popularity on a global scale? What are the advantages of modern lathes and turning centers? The answer lies in the speed, accuracy, and automation of production. With the wide range of lathes and special purpose products available on the market today, many industrial applications can be handled with high productivity. Additionally, with advances in hard coating and tooling technology, a typical lathe can machine: 

  • ferrous and non-ferrous metals, 
  • polyamides, 
  • thermoplastics, 
  • non-metallic engineering materials, 
  • wood, and many others. 


All this makes CNC lathes and turning centers the most productive machines. It is estimated that 40% of all metal cutting operations are performed on CNC lathes, where the majority of production is for rotary parts. So it should come as no surprise to anyone that this equipment is so popular!

Milling vs turning using CNC machines

If you understand how turning works, you will easily understand how milling works because it is a reverse process. During turning, the tool moves linearly and the part rotates, but during milling, the tool rotates and the part moves linearly along the x and y axes of the table. In milling, the Z-axis is the vertical axis of the tool. This is their fundamental difference. In addition, single point tools are often used in CNC turning, which is why turning is a „continuous cutting” process. On the other hand, the cutters (e.g. cutters, end mills, etc.) are multi-point cutting tools – in other words they have many tips. Grinding is therefore theoretically an „intermittent” process. You should also note the primary and secondary movements as well.

  • Secondary movement is a linear movement or feed motion.
  • The original motion is always a rotating motion.


This means that during CNC turning, the main movement takes place in the part and the secondary movement in the tool. During CNC milling, you make large movements on the tool and small movements on the part.

CNC lathe structure

Have you ever seen a typical CNC lathe? Its system consists of several components, each of which improves its efficiency. However, six of them are most important:

  • lathe bed,
  • headstock,
  • feed drive gear,
  • „Norton” gear,
  • lathe carriage,
  • tailstock,
  • lathe chuck.


In order to understand the design of the CNC lathe, let’s check the above mentioned elements. Lathe bed – is the main body of the machine. All other main components are connected and attached to it. It is most often made of cast iron, due to this alloy’s high compression strength and high lubricating properties. The cradle is made of castings and mounted to the ground. Guide rails on the machine bed provide smooth and accurate linear movement of the support and tailstock on the base.


The headstock contains a drive unit for turning the spindle, which in turn rotates the workpiece. The headstock is located on the left side of the tabletop. The headstock contains the gearbox and the main shaft. The regulator and related modules are located on the outside of the headstock.

​Feed drive gear or “Norton”

The feed gear has a system that regulates and maintains the linear speed of the tool in relation to the workpiece spindle. It consists of a feed controller and a draw bolt that rotates at the correct speed to reach the desired feed speed.

​Lathe carriage

The carriage is powered by a draw bolt, so it follows the feed speed controlled by the Norton transmission. The sliding table moves in a direction perpendicular to the movement of the trolley. When moving the carriage, the tool can be moved parallel to the working axle for easy turning. By moving the slider, the tool can be radially inserted into the workpiece for planning, profiling or cutting. The cutting tools are held in the tool holders attached to the transverse guides mounted on the carriage. The carriage slides on the lathe rails, supplying the tool parallel to the axis of rotation and parallel to the spindle axis with high precision. The rails are built into the lathe bed and provide a rigid frame for the lathe.


The tailstock is located on the opposite side of the headstock where a center is fitted to support the free end of the workpiece in order to balance it. In addition to centering, which is the main role of the tailstock, the drilling is carried out using centering and conventional drills installed in the tailstock assembly.

​Lathe chuck

The lathe chuck is used to hold the workpiece. It is mounted on the spindle of the swivel chuck and the workpiece. A typical lathe chuck can have three, four or five jaws depending on machining requirements, standard part geometry and desired clamping force.

​What CNC turning tools are available?

Many different engineering materials are available on the market, so it makes sense that cutting tools are made from different materials. When you need to select a material for your tool, never forget that the tool is exposed to:

  • high temperatures,
  • high contact stresses
  • strong abrasion.


The tool material must be selected according to the product being processed. Your primary objective should be to maintain the hardness and strength of the tool, especially in high temperatures. This will most likely result in the machining of high surface quality parts. However, other factors, such as cutting conditions and workpiece material, influence the final result, and are thus critical to achieving success. Cutting conditions are very important for the entire process. In order to maintain machining stability and keep tool wear as low as possible, it is recommended to set cutting conditions according to the technical manuals and recommended tool manufacturer specifications. Correctly setting up the cutting conditions will also extend tool life, reducing tool replacement costs. Other important factors to consider when selecting the cutting tool material are its resistance to wear and chemical stability. Of course, the higher the wear resistance, the longer the tool life. Regarding the chemical stability of the tool, the principle is “the higher, the better”, as it prevents harmful reactions that can accelerate tool wear. The most commonly used tool materials for CNC turning are:

  • carbide tools,
  • ceramic tools,
  • coated tools.

Using a CNC machine – benefits 

No matter what kind of part you want to make using CNC turning, the following are the advantages that are sure to convince you: 

  • Improved productivity and high precision – CNC turning involves simultaneous rotation of the part and linear movement of the tool. This synergy of movements makes the lathe a very efficient machine tool. Also, due to the very high stability of CNC turning centers, very high precision can be achieved. 
  • Generate less waste- As with any CNC machining process, the operator is responsible for setting up the job and ensuring that the CNC program is error-free and efficient. Operators do not participate or interfere in the manufacturing process. This in turn eliminates human error, thereby significantly reducing waste. 
  • Consistent run time – Free time includes tool changes, part alignment and orientation, and quick moves. Due to the automation built into CNC technology, downtime is significantly reduced.
  • Safety – Due to the fully automated production environment in CNC turning, operators are kept away from the work area and are not physically involved in the production process.


We hope that the above guide has helped you understand the basic issues involved in the use, application, and construction of CNC machines. As you can see, CNC machines are a great piece of equipment that can help automate and improve your entire manufacturing process on a large scale.