Oct. 07, 2024
Computer Numerical Control (CNC) machines come in different sizes, configurations, and technologies. Nonetheless, what these machines have in common is their use of axes, although the CNC machine axis count still varies from two to five. These axes typically include the linear axes as well as rotary axes. The CNC machine axes dictate the capabilities of the system, from the complexity to the size and shape of the part it can fabricate. The axes also influence the accuracy and precision of the machine.
For more information, please visit BH.
In this article, we discuss linear and rotary axes, concepts that introduce us to the different CNC machine axis configurations in various systems. We will explore the various types of CNC machines based on the number of axes they have, ultimately covering whether systems with more CNC machine axis counts are better.
Basics of CNC Machine Axes Linear AxesThe Cartesian Coordinate System is a reference system widely used in mathematics and other areas such as computer-aided design (CAD) and manufacturing. It is within the domain of manufacturing that CNC machines fall. This system is based on the concept of three mutually perpendicular axes that intersect at the origin. We refer to these axes as the linear axes, and they include:
X axis, which is the movement from left to right and vice versa (parallel to the cutting tool)
Y axis, which is the movement from front to back and vice versa (perpendicular to the cutting tool)
Z axis, which is the movement from top to bottom and vice versa (perpendicular to the cutting tool)
Indeed, we have grown used to the above-mentioned linear axes (X, Y, and Z) from our Math classes. However, when it comes to machining, a new class of axis &#; the rotary axes &#; enters the picture. Namely, the A axis, B axis, and C axis, these rotary axes help improve the accuracy and cycle times of fabrication processes. They do so by enabling the cutting tool to reach and work on a few more sides than would have been possible with linear axes. And as will be discussed in greater detail below, this is due to the part&#;s rotational shift in position.
Rotary axes get their name from their association with rotation. And given that these rotations always happen around one of the three linear axes, the relationship between rotary and linear axes becomes clearer. Typically, this relationship is as follows:
A axis is the rotation or tilt around the X axis; the A axis is also known as the tilt axis
B axis is the rotation around the Y axis
C axis is the rotation around the Z axis
So, what is a rotary axis or rotary axes? The rotary axes relate to rotations around the linear axes by the rotary table that enable the cutting tool to access parts at different angles in order to machine features on the fourth or fifth side of the part.
Understanding Linear and Rotary AxesYou can think of a CNC machine axis as representative of the side from and dimension along which a feature on a workpiece can be machined. However, the term side does not necessarily mean the external face. Instead, and for simplicity, it can also refer to any internal surface that is parallel to the external face of a cube or cuboid.
Starting from the basics, if you encounter a term such as a 2-axis CNC machine, that means the system can only machine features on two sides of a workpiece at a time. As will be detailed below, these machines comprise a combination of two linear axes.
Similarly, if you come across the term 3-axis CNC machine, remember that such a machine performs the cutting action on three sides of the workpiece at a time. These sides will typically be the length (X axis), width (Y axis), and depth (Z axis), with the cutting or drilling tool traveling left to right (and vice versa), front to back (and vice versa), and top to bottom (and vice versa), respectively.
The introduction of the rotary axes gives rise to 4-axis and 5-axis CNC machines, also known as multi-axis machines. But following the same principle introduced above, a 4-axis machine can work on four sides of the part at a time. On the other hand, a 5-axis machine can manipulate and fabricate features on five sides of the part secured in the vise at a time. The multi-axis CNC machines&#; additional capabilities, compared to the 2-axis and 3-axis machines, emanate from the ability of the cutting tool and rotary table (bed) to shift positions linearly and rotationally, respectively, which changes the part&#;s orientation relative to the cutting tool, exposing more sides.
2-Axis CNC MachinesAs the name suggests, the 2-axis CNC machine has moving components that travel along two axes. Depending on the type of machine and the work envelope&#;s orientation (i.e., horizontal or vertical), these two axes can be a combination of the x-axis and y-axis, the x-axis and z-axis, or the y-axis and the z-axis.
CNC lathe machines and turning centers fall into this category. They mostly support movement along the x-axis and z-axis. These machines have a number of components, but in this article, we will focus on the chuck, which attaches to the main spindle and holds the workpiece in place, and the cutting tool. The chuck, for its part, rotates around the z-axis. On the other hand, the cutting tool moves along both the x-axis and z-axis.
As far as the cutting tool is concerned, the X axis relates to inward or outward movement. On the other hand, the Z-axis is associated with longitudinal movement (i.e., along the axis around which the chuck rotates). The movement of the cutting tool influences the classification of CNC lathe machines and turning centers as 2-axis CNC machines.
Multiple manufacturers, such as Haas with its ST-series turning centers and Knuth with its Forceturn series, produce and sell high-performance CNC lathe machines and turning centers. Some compact vertical milling machines and high-precision CNC grinding machines also fall into this category of 2-axis CNC machines.
3-Axis CNC MachinesThe 3-axis CNC machine configuration is primarily found in CNC milling machines. In these machines, the workpiece is held in place by a vise. The vise, in turn, is fixed to a moving table. Designed to move, the table travels along the X and Y axes, while the drilling or milling tool travels along the Z axis. The combination of these movements means the CNC machine can simultaneously remove materials from the sides that correspond to the length, width, and depth.
This CNC machine axis configuration is ideal for machining simple parts with only a few features. These machines are also ideal for situations where the part does not require a lot of detailing. 3-axis CNC machines can also machine complex parts with numerous features. However, this will likely take longer than it would with systems that have more CNC machine axis configurations. More on this in the below section discussing whether more CNC machine axis configurations are better.
Examples of commercially available 3-axis CNC machines are EC-ZT, VF-1, VF-2SS from Haas Automation, the BO 90 CNC and BO T CNC 110 series from Knuth, the VX8 from Huron, and the GENOS M series machines from Okuma.
4-Axis CNC MachinesIn 4-axis CNC machines, the axis count is 4. Such machines have the capabilities of a 3-axis machine, i.e., their cutting tool and/or table can move along the X, Y, and Z axes. However, they also support rotation around one of these linear axes. This rotation is thanks to their use of either 4th-axis (single-axis) rotary indexing tables or a 4th-axis swivel head.
Rotary indexing tables have built-in motion systems comprising, among others, fixed motors that link to a fixture plate that rotates around a single axis. They expose a new surface for machining. This process is technically known in manufacturing as indexing. Accordingly, the part clamped onto the fixture plate rotates based on the CNC program generated by the Computer-Aided Manufacturing (CAM) software.
Generally, 4th-axis rotary tables are available in right-hand, left-hand, or bottom configurations, with a bottom-, top-, side-, or back-mounted motor. They also come in different sizes to accommodate different sizes of parts or fixtures. These rotary tables are compatible with CNC machines that have a 4th-axis drive and firmware that supports full 4th-axis operations.
However, not all machines utilize rotary tables. Some have a swivel head paired with a non-rotating table that is nonetheless capable of traveling along the linear axes. The swivel action of the head introduces 4th-axis rotation. However, this is more accurately described as a tilt because the movement does not constitute a complete 360º rotation. Examples of 4-axis swivel-head machines are the VMX42SWi, VMX60SWi, and VMX84SWi from Hurco.
5-Axis CNC MachinesA 5-axis CNC machine has a CNC machine axis count of 5. This number includes the three main linear axes (X, Y, and Z) and any two rotary axes. This means that a 5-axis CNC machine includes the X, Y, and Z linear axes, along with two of the following rotational axes: A, B, or C. The additional two axes in the 5-axis CNC machines originate from two different mechanisms, resulting in two types of 5-axis CNC machines:
Swivel-rotate-style 5-axis CNC machine
Trunnion-style 5-axis CNC machine
Also known as the swivel-head rotary table CNC machines, the swivel-rotate-style 5-axis CNC machines essentially have a swivel head that tilts around the B-axis, with a rotary table that rotates around either the A or C axis. This table supports the full 360º rotation, while the swivel head&#;s tilt is often less than 130º on either side of the vertical axis. It is worth mentioning that the tilt angle depends on the manufacturer. Hurco SRTi Series swivel-head rotary table machining centers support a maximum tilt of 92º on either side of the vertical axis, for example.
This type of 5-axis CNC machine is ideal for machining heavier parts. It is also less prone to tool interference issues. This is because the rotating table rarely interacts with the cutting tool, regardless of length. Moreover, the swivel-rotate-style machine offers flexibility and versatility. This is because it can machine both heavy and light parts.
Examples of swivel-rotate-style 5-axis CNC machines include the Hurco VMX60SRTi and VMX42SRTi.
Trunnion-Style 5-Axis CNC MachineThe trunnion-style 5-axis CNC machine introduces the rotary axes via dual-axis rotary tables and indexers. These dual-axis rotary tables orient the part to the cutting tool to take advantage of the cutter&#;s geometry. As a result, they expose as much as the part&#;s five sides to the cutter.
These tables tilt around the A or B axis by a specific angle on either side of the vertical axis. This angle typically depends on the manufacturer. CNC machines from Haas Automation support a maximum tilt of 120º each way. In contrast, those from Huron support a maximum of 110º. However, when it comes to the movement around the C axis, all rotary tables and machines support a full 360º rotation.
However, these machines have a downside. Due to the rotary table&#;s continuous rotation and twisting of the part, the risk of tool interference significantly increases. Additionally, the rotation limits the weight of the part that the table can support. In this regard, trunnion-style machines are mostly ideal for machining light to medium-weight parts.
Some examples of Trunnion-Style 5-Axis CNC machines are the VC500i and VCX600iXP from Hurco, the VC-X350from OKK, and the VR series and UMC series machines from Haas.
Multi-Axis CNC MachinesMulti-axis machines are those that have a CNC machine axis count that is greater than three. This means such machines have one or two rotary axes on top of the three linear axes. Compared to conventional CNC machines with two or three linear axes, multi-axis CNC machines offer several advantages:
Multi-axis CNC machines require fewer setups as their cutting tools can access more sides than conventional machine&#;s cutters and mills
The fewer setups translate to less cycle time, i.e., the amount of time spent machining a part with all designed feature
These machines are more accurate because they eliminate the likelihood of human errors during setup &#; they have fewer setups and part-loading instances
As with all other machines, multi-axis CNC machines also have a few disadvantages, including:
They are more expensive to purchase than conventional CNC machines
Multi-axis CNC machines, particularly the trunnion-style 5-axis machines, are prone to collisions between the nose of the spindle of the machine and the side of the rotary table
While the first disadvantage is unavoidable, measures can be taken to prevent the second. Running the machine slowly after loading the part can ensure safety and allow you to monitor the spindle nose&#;s proximity to the rotary table. If you establish that a collision is more than likely, there are two approaches you can take. First, you can use longer tools. Alternatively, you could attach your tools to an ER collet chuck to elongate them. That said, a few questions linger.
3-Axis CNC Machine vs. 5-Axis CNC MachineAre higher CNC machine axis counts better? Are multi-axis CNC machines better than conventional CNC machines? To help answer the questions, Haas Automation conducted an analysis. In this analysis, a machinist separately created two identical parts using a 3-axis CNC machine and a 5-axis CNC machine. Though the analysis was not scientific, it offers insights that point to the fact that multi-axis CNC machines are better for machining parts with a high level of complexity.
This is because the use of the 5-axis CNC machine resulted in a 26.6% reduction in the cycle time. This implies that the machinist took less time to machine the part with the 5-axis machine compared to the 3-axis machine. Moreover, the former required just two setups or part loadings, compared to the latter&#;s five setups. The machinist also had to set the work offset during each setup. This means there were five different sets of work offsets in the 3-axis machine. In contrast, the 5-axis machine just required two. Furthermore, the fewer setups and work offsets because of using the latter dramatically reduced the chances of human error.
Another drawback of the 3-axis CNC machine that the analysis uncovered relates to tooling. The machinist had to constantly change the tool. And he did so even when that tool was required later to machine a feature on the part&#;s other sides. This added a few minutes to the cycle time. In contrast, the 5-axis machine would complete all machining operations required of the cutter by simply changing the part&#;s orientation. Only after the cutting tool had finished its job would it be changed. This helped reduce the cycle time.
Are Higher CNC Machine Axis Counts Better?So, are more CNC machine axis counts better? Yes, they are. In fact, they are preferentially used in high-performance machine shops for pretty much this reason. However, multi-axis CNC machines may not be suitable for all types of machining jobs. This leads us conveniently to the next section, which discusses what goes into choosing the right number of axes.
Choosing the Right Number of AxesThere are numerous factors to consider when choosing a particular CNC machine axis count. These include:
Cost
Function
Part complexity
Future Plans
Different CNC machine systems come with varying costs. Naturally, 5-axis CNC machines are more expensive than 3-axis CNC machines. This is because you need to purchase additional accessories, e.g., the trunnion-style rotary table, longer tools, and collet chucks. However, industrial-grade, high-performance 2-axis CNC turning centers can also carry a high price tag. So, the cost may not always be the most crucial factor to consider when choosing the most appropriate CNC machine axis count for your machine shop.
FunctionIndeed, Haas Automation established that 5-axis CNC machines are inherently better than 3-axis machines at working on complex parts. However, multi-axis machines are not always ideal for all operations. In machining jobs that require 2-axis CNC machines, such as the CNC lathe or grinder, systems with more CNC machine axis counts will not cut it. Therefore, considering the intended function is crucial when selecting the appropriate number of axes.
Part ComplexityThe complexity of a part increases the number of machining operations and tools to be used. And if the machined features are found on multiple sides of the part, then its orientation should be constantly changed. This is done to ensure the cutting tool accesses the different sides. Here, you can use a 3-axis system or a multi-axis system with a CNC machine axis count of 5. However, the former would require additional setups and sets of work offsets, which could compromise accuracy. In contrast, the latter would be a better option thanks to fewer setups and sets of offsets.
Future PlansIt is also important to consider your vision for your machine shop. This should be the case even when your current budget does not allow you to actualize this vision. Do you wish to scale up your operations? Are you looking to eventually reduce operational expenditure by lowering the cycle time? If the answer to both of these questions is an emphatic yes, you could initially purchase a machine whose capabilities can be upgraded later via the purchase of accessories. For instance, you can purchase a 3-axis CNC vertical milling machine that supports the fourth- and fifth-axis drives. You can then enhance your machine shop&#;s capabilities later by adding a trunnion-style rotary table.
ConclusionEach CNC machine has a specific CNC machine axis count, depending on whether it employs only linear axes (X, Y, Z), or a combination of linear and rotary axes (A, B, C). While the CNC machine axis configuration is factory-imposed, you can increase the count for some types of machines by purchasing accessories such as a rotary table. All in all, the number of axes found in CNC machines influences their capabilities and functions. For example, while multi-axis machines are optimal for complex parts, 3-axis CNC milling machines are more suitable for simpler operations. Besides the function and part complexity, there are other factors you should consider when choosing the right number of axes. When choosing the right number of axes, consider factors such as function, part complexity, cost, and your machine shop&#;s future plans.
You probably know what is CNC turning and how it works; but let&#;s remember again some of its basic operations so that you fully understand its fundamentals and make the best use of the overall article.
With CNC lathes, the geometry of machined components is formed by removing the material. During turning, the workpiece rotates about a hypothetical axis, which is held in the lathe chuck. This axis is the Z axis and holds the major motion which is the rotary motion. The cutting tool has the secondary motion that is the feed.
When the cutting tool comes in contact with the workpiece surface, the material is removed; this is how cutting is done with lathes. In more detail, the cutting tool is on one side of the workpiece diameter on X-axis and the machined surface is produced diametrically, around the Z axis. The cutting tool can move either longitudinally or transversely (i.e. in a straight line parallel to the workpiece&#;s Z-axis, or transverse to the axis of the piece) or even as a combination of longitudinal and transversal motions.
The workpiece can take several geometries. Which geometry the workpiece will take depends on the combination between the two axes (rotation and feed) as well as the cutting tools to be used. In turn, the cutting tools to be used depend on both the kind of the desired surface to be produced as well as the type of turning operation (for instance, either internal or external).
But it is not only about the typical CNC turning. In modern CNC lathes, a variety of other machining operations can be performed. These include:
&#; Contour turning &#; the tool follows a contour that is other than straight, thus creating a contoured form in the turned part.
&#; Taper turning &#; the tool is fed at an angle, thus creating a tapered cylinder or conical shape.
&#; Chamfering &#; the cutting edge of the tool is used to cut an angle on the corner of the cylinder, forming a &#;chamfer.&#;
&#; Facing &#; the tool is fed radially into the rotating workpiece starting from the outside or the inside diameter on one end, to create a flat surface on the face of the workpiece.
&#; Form turning &#; the tool has a shape that is imparted to the work by plunging the tool radially into the work).
&#; Boring &#; a single-point tool is fed linearly, parallel to the axis of rotation, on the inside diameter of an existing hole in the part.
&#; Drilling &#; it can be performed on a lathe by feeding the drill into the rotating work along its axis. Reaming can be performed in a similar way.
Want more information on 2 axis cnc turning machine? Feel free to contact us.
&#; Grooving/Cut-off &#; the tool is fed radially into the rotating work at a location along its length to either groove or to cut off the end of the part. Cut-off operation is sometimes referred to as parting.
&#; Threading &#; a pointed tool is fed linearly across the outside surface of the rotating work part in a direction parallel to the axis of rotation at a large effective feed rate, thus creating threads in the cylinder.
&#; Knurling &#; this is not a machining operation because it does not involve cutting of material. Instead, it is a metal forming operation used to produce a regular cross-hatched pattern in the work surface.
You surely have heard about 2-axis and 3-axis lathes. Their difference is what their names imply. With 2-axis lathes the work is done on 2 axes, whereas with 3-axis lathes the work is done on 3 axes. Apparently, 3-axis lathes offer more possibilities.
But let&#;s shed some more light on this.
What we have said so far refers to 2-axis lathes: X and Z; and you program two axes. Then, the tool moves linearly as the part is rotated around its axis. The linear travel of the tool can be longitudinally or vertically to the imaginary axis (Z-axis) of the part. This is the simple kinematical principle for a lathe which is shown in the figure below.
3-axis lathes include an additional axis, which is rotary. It is the so-called C-axis. With 3-axis lathes, you can surely expect to do more.
With 3-axis lathes, you can handle and program some milling operations. More specifically, you can change the orientation of the tool with respect to the part&#;s rotational axis and perform slots, holes, and several peripheral features, according to your drawing&#;s requirements.
By using a &#;live&#; tool (C rotary axis), you practically add a rotational motion to your tool. In order for the &#;live&#; tools to be functional, they should have their own servomotor or an identical motion-transmission system.
To better understand the kinematics of a CNC turning center, we will show you a video later. It is the video that shows how the final part of the picture below is machined.
But first, let's examine some features of the final part. As you see, it is a rotational part, yet with a milled surface in its outer diameter. On the surface, four holes have been drilled; two of them have been tapped as well. The flange of the part has peripheral holes. It is a complete part with turning and milling features.
The video below shows how this part is made in a 3-axis CNC turning center. You will see 2-axis, as well as 3-axis machining operations, all done in the same setup. Let's watch it :)
For a better understanding, let's describe below in more detail the steps of the machining operations shown in the video. The pictures below are screenshots of the video.
Step 1:
First, the part is clamped to the lathe chuck and a face cutting is performed by vertically moving the tool in X-axis while the part is rotated.
Step 2:
What follows next, is the roughing operation for the part&#;s diameter. This is done by moving the tool longitudinally in Z-axis. In addition, you can see that a smaller diameter is also machined in the part.
Step 3:
After changing the tool to select a thread cutting tool, a threading operation is performed in the small diameter of the part. This is done by moving the tool longitudinally in Z-axis in a sequential manner (as shown in the video).
So far you have seen indicative examples for 2-axis CNC turning, right? Now let's see the rest operations which are all based on the capabilities that the 3rd axis offers.
Step 4:
Next is a milling operation performed using a flat end-mill which has a rotational motion as a &#;live&#; tool. The tool machines a flat surface on the cylindrical contour of the part.
Step 5:
Having machined the flat surface on the cylindrical contour of the part, drilling is conducted, to produce the holes. You will notice that the drill has its own rotational motion with respect to the part. The part has stopped its rotation!
Step 6:
Next, you can see that a tapping tool is selected to perform tapping operations in the holes. This is also a cutting tool with its own rotation with respect to the part.
Step 7:
In the last picture, a drill is now ready to machine a set of peripheral holes to the part&#;s flange. In this case, the lathe chuck operates as an indexer, to properly position the part at the correct angle.
The lathe is one of the oldest machines invented; however, modern lathes have been significantly upgraded by incorporating several technological achievements. The lathes have evolved in parallel with other types of machine tools and as a result, they are widely used by industry today.
But why the lathes have gained the trust from the industry? What are the benefits of modern lathes and turning centers?
In a few words, the answer is production speed, accuracy and automation.
But it&#;s not only that. Due to the variety of specialized turning machine tools and lathes which are available in the market today, numerous industrial applications can be handled with high level of productivity. Also, with the progress of technology in hard coatings and cutting tools, a typical lathe can process ferrous and non-ferrous metals, non-metallic engineering materials, polyamides, thermoplastics, wood, and so on.
All the above have made CNC lathes and turning centers the most productive machines. Actually, it is said that 40% of metal cutting operations are executed in CNC lathes; and most of the production with CNC lathes is about rotational parts. This is the nature of a lathe!
If you understand how turning works you can easily understand how milling works; because it&#;s exactly the opposite. In turning the tool moves linearly and the part rotates; but in milling, the tool rotates and the part moves linearly in X and Y axes of the working table. In the case of milling, Z-axis is the vertical axis of the tool.
That&#;s their fundamental difference. But it is not their only difference.
In CNC turning, you normally use single-point cutting tools; this is the reason why turning is a &#;continuous cutting&#; process. On the other hand, milling tools &#; such as cutters, end-mills and others &#; are multi-point cutting tools; in other words they multiple cutting edges. Therefore, milling machining is theoretically an &#;interrupted cutting&#; process.
You should also be aware of the major and secondary motions. The major motion is always the rotational motion, whereas the secondary motion is the linear motion, i.e. the feed rate. This suggests that in CNC turning, you have your major motion in the part and your secondary motion in the tool. In CNC milling, you have the major motion on the tool and the secondary motion on the part!
Based on the above information you might easily understand the applicability of turning and milling given the geometry and features of your part. When it comes to rotational parts, you select turning to machine. If it is about prismatic parts with several milling features, you select milling.
Nevertheless, if your machine shop is equipped with additional apparatus like indexers or trunnion tables for milling, or a third axis (C-axis) for CNC turning, you can execute milling operations in turning machines (with &#;live&#; tools) and turning operations in CNC milling machines. However, the additional equipment comes with its cost and this should be justified by the cost of products you manufacture
In CNC machining, productivity and success not only depend on the proper selection of the machine tool, but also on other factors such as suitable tools, work-holding and cutting conditions. It is not enough to know what part is more proper for which type of machining. You should always be sure about some additional conditions that need to be satisfied on order to secure the best possible outcome.
Let&#;s dive into this a bit more.
In overall, no matter what type of machinery you have or what type of machining you have to execute, there are some general tips and guidelines you should keep in mind. For example, you should always check the coolant type and your cutting conditions; also, you should be aware of the work-piece material and its properties in order to ensure the best possible result and accuracy of your machining work; that is because different materials with different properties behave differently in machining.
In addition, keep in mind that the stability and power of your machine are key factors affecting the accuracy and productivity of your manufacturing process, no matter whether you work in milling or turning. It is critical to know the possibilities of your machines in terms of stability and power &#; as these are defined in the manufacturer&#;s technical specs &#; so that you can judge how demanding work they can execute, basically in terms of high-speed machining, different-to-cut materials, etc.
An important issue will always be the configuration of your equipment, given any of its technological constraints. Generally speaking, the simpler your machinery, the more limited work it can execute.
If you&#;re still not sure whether your part should be best produced by CNC Turning or CNC Milling, you can always use contact us at to get in touch and receive answers to your questions.
Have you ever had the chance to observe a typical CNC lathe? Several components comprise its system and each one contributes to operational efficiency with its own way.
However, six of them are the most critical:
Let&#;s examine them one by one.
The machine bed is the main body of the machine. All other main components are attached and fastened on it. It is usually made with cast iron due to the high compressive strength and high lubrication quality of this alloy. The machine bed is made by casting operations and it is secured on floor space. The guideways &#; which are positioned on the machine bed &#; ensure the smooth and accurate linear motions of carriage and tailstock on the bed.
The headstock contains the drive unit to rotate the spindle, which in turn rotates the workpiece. The headstock is on the left upper side. The headstock contains the gearbox and the spindle. The outer part of the headstock contains the speed controller and its associated modules.
Photo source: https://www.quora.com/What-is-a-lathe-headstock
The feed gearbox contains the system which is responsible for adjusting and maintaining the linear speed of the cutting tool in relation to the spindle of the workpiece. It consists of the feed controller and the lead screw that rotates at the proper speed to obtain the desired feed rate.
Photo source: https://www.pinterest.com/pin//
The carriage is driven by the lead screw and thus it follows the feed rate controlled by the Norton gearbox. The cross-slide feeds in a direction perpendicular to the carriage movement. By moving the carriage, the tool can be fed parallel to the work axis to perform straight turning. By moving the cross-slide, the tool can be fed radially into the work to perform facing, form turning, or cut-off operations. The cutting tool is held in a tool post fastened to the cross-slide, which is assembled to the carriage. The carriage slides along the slideways of the lathe to feed the tool parallel to the axis of rotation with great precision for parallelism, relative to the spindle axis. The slideways are built into the bed of the lathe, providing a rigid frame for the lathe.
Photo source: http://www.lathes.co.uk/wabeco/page8.html
The tailstock is placed at the opposite side of the headstock, in which the center is mounted to support the free end of the workpiece to counterbalance it. Apart from centering, which is the major role of the tailstock, drilling is also performed by using center drills and common drills which are attached in the tailstock unit.
Photo source: https://www.haascnc.com/productivity/workholding/mt6.html
The chuck is used to clamping and hold the workpiece. It is fastened on the spindle that rotates the chuck and workpiece. Typical lathe chucks can comprise three four or five jaws depending on machining requirements, standard part geometries, and clamping forces required.
Photo source: https://www.haascnc.com/service/troubleshooting-and-how-to/troubleshooting/hydraulic-chuck-troubleshooting-guide.html
There is a wide range of CNC Turning Centers in the market. Usually, the available CNC Turning Centers are categorized based on the number of their working axes and their spindle orientation.
With reference to the number of working axes, there are the following types:
With reference to the orientation of the lathe spindle, there are two types of CNC Turning Centers in the market: the vertical and the horizontal ones.
There is a wide variety of engineering materials in the market, so it is very reasonable that there is also a wide range of materials which cutting tools are made from.
When you need to select the material for your cutting tool, never forget that during machining, the cutting tool is subjected to high temperatures, high contact stresses and high shearing forces. The material of the cutting tool should be selected based on the material that the cutting tool will machine.
Your major goal should be to maintain the hardness and strength of the tool, especially at elevated temperatures. This will most likely lead to machined parts with high-quality surfaces. However, other factors affect the final outcome, such as the cutting conditions and the material to be machined, which are critical success factors.
Cutting conditions are very critical. In order to maintain stability of machining and keep the tool wear rate as low as possible, it is highly recommended that the cutting conditions are set according to technical handbooks and recommended specs of the tool manufacturer. Setting the cutting conditions properly will also result in a longer tool life and consequently, reduce the tool replacing costs.
Other important factors you should take into consideration when selecting the cutting tool material, are its wear resistance and chemical stability. Obviously, the stronger is the wear resistance, the longer the tool life. Regarding the chemical stability of the tool, the higher it is, the better prevents adverse reactions that may accelerate tool wear.
The most often-used cutting tool materials for CNC turning are carbides, ceramics and coated tools. These cutting tools are commercially available in the form of cutting inserts with standard geometry, as you can see in the following picture.
The geometry you should select depends on the application.
Another factor playing a critical role is the tool holders. Specific geometries of cutting inserts come with their dedicated tool holders. In order to maintain cutting efficiency and stability, you should select the proper tool holder depending on the geometry of the insert. Having selected the right tool holder will also extend the tool life.
In the figure below, you can see an assembly between the tool holder and its corresponding cutting insert. On the left side of the figure, you can see the special geometry of the tool holder, where the insert should be mounted. In the center of the figure, you can see the complete tool holder assembly. On the right side, you can see the type of cutting insert geometry corresponding to the tool holder.
As expected, there are quite many CNC machine shops providing turning services in the market. Not all of them are equally good or experienced at their job.
Let&#;s see below what are the main qualities you should be looking for when selecting your CNC turning partner.
Experience matters! Only CNC machine shops with long experience can offer a variety of solutions by taking advantage of the technologies presented above. Moreover, technologies evolve rapidly; thus, CNC machine shops should be prepared to keep up with the technological advances and implement them at their work when needed.
Besides delivering complete and high-quality machined parts, your selected CNC machine shop should additionally be able to provide supplementary supportive services such as polishing, sandblasting, anodizing, sterilization, laser marking, assembling, fast &#;on-time&#; product delivery, etc.
The cutting tools play a critical role in CNC turning. In other words, keep in mind that your selected CNC turning provider must have the right tools to provide high-quality turning work. It&#;s always beneficial to discuss with your partner the materials and methods they are going to implement so that you have a better understanding of their overall knowledge, experiences, and resources to complete your work at the expected standards.
Many CNC machine shops are equipped with ERP systems (Enterprise Resource Planning), online monitoring, and full production and batch traceability. These resources are evidence of good management of their internal operations, securing that the right processes are always followed and minimizing the risks associated with the quality of your CNC parts.
CNC turning is used when rotational parts are to be machined. This includes parts with milling features provided that your CNC turning machine supports the third axis.
A typical list with parts you can produce by implementing CNC turning is the following:
Regardless of the part that you want to produce with CNC turning, there are standard benefits that you can expect to gain. Let&#;s see them one by one.
Productivity increase and high precision
CNC turning engages the simultaneous rotational motion of the part and the linear motion of the tool. Owing to this synergy of motions, the lathe is a very productive machine tool. In addition, owing to the very high stability of the CNC turning centers, very high precision is achieved.
Reduction of scrap owing to automation
As it occurs in any CNC machining process, the operator is responsible to set the job and make sure that the CNC program is error-free and productive. Operators do not involve or interfere during the manufacturing process. This, in turn, eliminates human errors, and thus, scrap material is greatly reduced.
Reduction of idle time
Idle time involves tool changes, part setup and orientation and rapid traverse motions. Owing to the automation that CNC technology embeds, idle time is dramatically reduced.
Work safety
Due to the fully automated production environment in CNC turning, the operator keeps distance from the working area and is not involved physically in the production process.
Are you interested in learning more about cnc lathe vs cnc mill? Contact us today to secure an expert consultation!
Previous: None
If you are interested in sending in a Guest Blogger Submission,welcome to write for us!
All Comments ( 0 )