5-Axis CNC Machining: The Complete Guide

Introduction to 5-axis CNC machining

When people talk about multi-axis CNC machining or multiple machining, 5-axis CNC machining is always mentioned in the advanced manufacturing methods. Full 5-axis CNC machining means a machine’s processing ability to move a tool or a workpiece in five different axes simultaneously. 5-axis CNC machining is considered a more evolved and sophisticated version of the CNC machining process.

What is 5-Axis CNC Machine?

As we all know, 5-axis CNC machining is achieved by 5-axis CNC machines. Nowadays 5 axis CNC machines are considered incredibly excellent for creating complex shapes with better surface finishing. People can learn much about 5-axis CNC machining once they understand how 5 axis CNC machines work in a CNC machine shop.

In the 5-axis machining process, there are two additional axes as compared to the X, Y and Z-axis. The two additional axes can be either A and B, A and C, or B and C Axis. They are involved to complete the machining process of highly complex shapes. Now the question is how the other two axes are deployed in the 5-axis CNC machining process?

The extra two axes are utilized by the movement of a table on which the job material is fixed. Thus, the table can rotate in either way to 360 degrees around the cutting tool that giving the machine accessibility to side cutting. Meanwhile, if we consider a single axis movement like either in A, B or C position the rotation is limited to 180 degrees. In the 5-axis machining process either there is swilling of tool head against the still job material or there is the rotation or movement of a table at an angle that gives the table a tilt position. Depending upon the features requirement, the table can tilt in different angles to achieve the complex shapes. According to the size and weight of the object that is subjected to the required manufacturing product, the selection of either the swiveling or rotation of the table is decided. If the job is heavier, then it is subjected to swivel, otherwise, 5-axis machining goes with table tilt to perform the required machining process. There are also different varieties of 5-axis machining due to types of 5-axis CNC machines.

 

What are the types of 5-axis CNC machines?

To meet the different needs of the market, CNC equipment manufacturers provided different types of 5-axis CNC machines.  Among the types, there is a basic difference in the flexibility of table rotation or cutting tool movement in different directions. They are mainly concluded as the following five types of 5-axis CNC machines.

1. Double Pivot Spindle Head Type

In this type, two rotating coordinates control the direction of the tool axis directly.

2. Pitching Swing Head Type

The two coordinate axes are at the top of the tool, but the rotation axis is not perpendicular to the linear axis.

3. Double Rotary-Table Type

Regarding this type of 5-axis machining, two rotating coordinates directly control the rotation of the space.

4. Pitching Work Table Type

The two coordinate axes are on the worktable, but the rotation axis is not perpendicular to the linear axis.

5. Rotary Table + Pivoting Spindle Head Type

In this type, the two rotating coordinates act in different places. One acts on the tool and one acts on the workpiece.

 

 

5-axis CNC machining VS 3+2 machining VS 4+1 machining

5-Axis Machining = 5-Sided Machining？

Many people still can’t distinguish between 5-axis CNC machining and 5-sided machining though they’ve explored in CNC processing industry for many years. They even often confuse them or think 5-axis CNC machining refers to 5-sided machining. In fact, they are different from each other. In this section, we’ll explain their differences in detail.

3+2 axis CNC Machining

3+2 CNC machining means the three axes of a machining center, plus one rotary and one tilt. 3+2 CNC machining is also known as five-sided machining. It means you can machine five sides of a part in a single set-up.

In this version of the CNC machining process, three axes are used simultaneously while the other two axes are used to reposition the job subjected to manufacturing. For example, if we are controlling the X, Y and C axis at the same time then the Z and A axis will be utilized for positioning purposes.

4+1 axis CNC machining

4+1 CNC machining means it uses a 5-axis machine structure but holds one of the rotary or tilt axes fixed. 4+1 machining is more capable than 3+2 CNC machining. However, it’s still not real full 5-axis CNC machining.

In this machining process, it is clear that the four axes will be employed at the same time while only one axis stays still that will be deployed for the positioning function. For example, we can go along with the X, Y, B and C axis simultaneously while the Z-axis will be used for setting the position of the material.

Full 5-axis CNC machining

Regarding full 5-axis machining, it refers to that all five axes of the machine are moving at simultaneously (3 linear axes, one rotary and one tilt axis). It’s capable of producing very complex parts. It’s 5-axis linkage machining.

In this case, all the five-axis works at the same time to achieve high-end results. The conventional three-axis such as X, Y and Z axis are deployed for the translational motion while the other two axes are commonly referred to as B and C axis are utilized for the tilt or complete rotation of the tool or the job post depending upon the features of the CNC machine.

5-axis CNC machining is a suitable method for hook surface machining, unusual shape machining, hollow machining, oblique hole, etc. While 5-sided machining is similar to but more capable than 3-axis machining. It can only process five sides but would fail to achieve some special machining in one single set-up.

The programming procedure of 5-axis CNC machines is quite similar to traditional 3-axis CNC machines in which first the user creates the CAD model of the desired product. Then the software generated the G-code for the part model accordingly. However, 5-axis CNC machines involve the angular values in addition to axial values which makes the G-code a bit more complex. The angles are defined depending upon the configuration of the table and head of the 5-axis CNC machine.

The tools used in 5-axis machines are also upgraded in respect of their geometry and shapes. More swift shapes and geometries of cutting tools give better results in the form of tolerance and fits of ending products. However, the type of materials is still similar to conventional methods that depend upon the strength of the cutting material.

Bonus:

1. 5-axis machining or five-axis machining is sometimes abbreviated by simply saying 5X CNC machining.
2. In actual order production, 90% of work was done by a 5-axis machines is actually just 5-sided (positioning only). Do you know why? Due to the structure and actual requirements of parts, the function of five axis linkage has not been brought into play. That’s why people confused 5-axis CNC machining and 5-sided machining.

 

Prices of 5-axis CNC machines

Prices of 5-axis CNC machines are generally very high and vary a lot depending upon the features and type of CNC machine. The cost goes from $10,000 to $500,000 depending on different factors. However, small industries with low manufacturing capacity can acquire the services of such innovative technology at hourly rates. Companies that manufacture 5-axis CNC machines generally provide such customized solutions regarding 5-axis CNC machining

Configuration Types for 5-Axis Machining Center

Table-table, head-table, and head-head are examples of common 5-axis CNC machine combinations.

The first configuration is the table-table configuration, also characterized as a trunnion table machine. Both rotary axes are contained in the trunnion table and the head is always stationary, rotating the piece on the table. This setup is based on a standard 3-axis CNC machine, with the two rotary axes used to position the workpiece in the desired orientation. The trunnion CNC machine provides better undercut capabilities, larger work volumes, and better speed and durability. The swivel or articulating head machine, which is available in head-head or head table configuration, is the second 5-axis machine configuration.

Unlike a trunnion-style, head-head machine, where the head performs all rotations, the table is static. The head-table machine, but from the other side, is made up of a tilting head and a rotating table, which allows for the use of shorter or more standard-length tooling. Swivel head machines can move the tool head around the block to fit into small spaces. Swiveling the spindle sets up rotary axes so that heavier materials can be processed and shaped in 5-axis CNC machines easily.

Why Go 5-Axis CNC Machining?

The benefits of 5-axis CNC machines are vast. These machines are used in different manufacturing groups such as medical instruments that require very smooth and complex shapes, aerospace equipment that requires high-end surface finishing and smooth ends, other sectors that require a tight tolerance and manufacture products in bulk.

One of the basic needs of the 5-axis machining process is the agility to perform subtractive processes and obtain those complex geometries that are quite difficult to obtain with conventional 3-axis CNC machining. For example, when we need cutting, drilling and tapping operations all at the same time on different faces of a piece of material at different angles then a simple CNC machine requires a lot of effort to do so. The user must have to change the positions of the job to create angles throughout the cutting process if he goes with a simple CNC machining process. This will take a lot of time and effort to do so. This is where 5-axis CNC machines efficiently finish the job.

5-axis CNC machine can create such shapes and angles in one go thus reducing time and efforts with increased accuracy and surface finishing qualities. When different shapes and geometries are achieved, and lead time reduces it increases the production volume with even mix production. Industries like aerospace, automotive, medical and similar others that require their products to be highly precise and accurate profiles, 5-axis machining serve the best. As human involvement is reduced in the process of machining process thus high tolerance and standards are achieved with 5-axis CNC machines. Anyone with the right machine with good CAD (computer-aided design) knowledge and materials selection can utilize the 5-axis CNC machines to create their products apart from the company manufacturing.

Advantages of 5-axis CNC machining

When we come to this far, we can conclude the advantages of 5-axis CNC machines as follows:

1. Reduce lead time and increase production speed
2. Improve the accuracy and quality of the machining process
3. Agility to obtain complex geometries and shapes
4. Expand the production capacity
5. Replace the different machining equipment with a single 5-axis CNC Machine
6. Reduce potential errors at each stage of the machining process
7. Longer cutting life spans due to automatic tool selection and optimized cutting tool speed.
8. High end surface finishing due to less vibrations in 5-axis CNC machines

Programming 5-Axis CNC Machine

The procedure of creating G-code for the CNC machine starts from a CAD model designed in any modeling software. Then the CAD model is generally turned into an algorithm i.e., G-code that contains all the required information such as speed of the spindle, feed, and axial movements of the cutting tools. The algorithms used to control the high-speed cutting tool of 5-axis CNC machines are not much different from the conventional 3-axis machining G-Code. However, the movement of the cutting tool at different angles or incline the position of the table requires the information of advancing angles and curvature paths. 

 

When programming on the 5-axis, we have two possibilities for controlling rotating movements and positions. We can use rotary angles or tool vectors to output the data. Tool vectors are basically the commands that are deployed at the end of X, Y and Z axis that give the information to the tool to rotate or tilt at a specific angle. The application is unique to each different machine setup due to the use of IJK tool vectors. The machine is permitted to use whatever axes it has available to position the tool to its commanded position and tilt angle because it is not commanding any specific axis callout (A, B, or C). This flexibility allows the same part programmed to be shared across multiple machines in the shop regardless of machine configuration.

There are different CNC programming software suits that can be used to create the G-code that is deployed in 5-axis CNC machines. Software like Autodesk, Mastercam, Siemens NX, PowerMill and Edgecam are the most commonly used software to program 5-axis machines.

Steps to consider while doing 5-axis CNC machining Process

• Ensure there is sufficient processing rate of CNC machine to control the path of cutting tool commanded by the G-code uploaded in the CNC machine.
• For making fully functional CNC operations also make sure the look ahead functions that allows the NC machine to calculate faster.
• Choose the best tool holder system for the CNC machining process that ensures the vibration free motion of the tool while creating a profile on the material.
• Control the feed rate during the condition to maintain the durability of the cutting tool. Controlling the speed of cutting tools on different materials is the basic key to increasing the life of the cutting tool.
• Another very important factor to keep an eye on is the spindle heat control by using proper coolant. Hence different lubricants or water jet systems are used to keep the temperature of the cutting tool tip low and clear the scrap from the cutting tool position.
• Also, before subjecting you’re your workpiece to manufacturing directly in the 5-axis CNC machine it is better to do tool path simulation that can ensure the right process is performed with correct results.

Cutting Tools for CNC machining process

Cutting tools material used for cutting or shaping the job subjected in 5-axis CNC machines are not different from 3-axis CNC machines. However, the tool holding stations are quite different and tool changing capability in 5-axis CNC is much upgraded. They also include automatic workpiece changes or automatic pallet changer that reduces the human interaction with cutting tool and material during the manufacturing process. This flexibility also allows the High Mix or Low Volume production which increases the efficiency of any manufacturing company. In 5-axis CNC machining there are 60 to 120 tooling stations in the automatic tool changer magazine. A greater number of tooling stations provides the adjustment of working on quite complex designs.

The selection of cutting tool material depends upon different factors such as the tool materials should be 40 to 60 percent stronger than the material on which it works. Similarly, it should have high thermal conductivity with a low coefficient of friction. Also, the cutting tool material fabrications should be easy so that they could be easily accessible. Some of the cutting materials used in CNC machining are given below:

Carbon Steel

This material is the most popular cutting material used in CNC machining due to its availability and low cost. This contains a small amount of manganese and silicon with 0.6 to 1.5% of carbon content.

High-Speed Steel

This material is the second most abundantly used in CNC machining because of its durability and high wear resistance. It contains tungsten, chromium, molybdenum with a reasonable amount of carbon steel.

Cemented Carbides

These materials are used for very high-speed cutting material operations since this material have high thermal resistance and can withstand temperature like 1000 degree centigrade. Its composition involves mainly tungsten, titanium and tantalum.

Ceramics

This material is chemically inert and gets no corrosion so it can last longer as compared to metallic cutting tools in corrosive environments. These tools are even ten times faster than HSS. Their material is majorly composed of silicon nitride and aluminum oxide.

Other cutting tool materials include a diamond tip, carbon boron nitrides or cermet.

Cutting Tool Geometries

5-axis cutting tools are slightly different from conventional ones since they are subjected to angle cutting so they have to be more flexible with their shapes for performing the job.

End Mills: These are the rotary cutting tools that can be used to remove materials, especially in 5-axis CNC machines. The end mill like the drill bit is used for more multipurpose machining operations. End mills are lateral cutting tools that cut in any direction, as opposed to drilling bits, that can cut axially to the material. Different categories of end mills are:

Ball Nose End Mills: This type of end mill has ideal 3-D contour action that generates top-level curved profiles. Tilting the tool axis makes it possible for the flutes to grab the material, pulling it away from the part rather than pushing it, causing it to build on itself, the cutter, and the part surface.

V-Bits: These are also a kind of End mills and are generally available in two variants i.e., 90^o or 60^o that completely depends upon the depression required on the material under manufacturing.

Multi-flute End Mills: When there are more edges in play with more flutes on a cutting tool, the machining process can maintain higher speeds and feeds. Furthermore, the extra flutes increase the tool’s cutting surface, resulting in longer tool life. These benefits add up to significantly higher metal removal rates, a better surface finish, and control of the overall costs.

Twisting Drills: This cutting tool has two flutes with two sides to remove the material from the job. These are the most common type of cutting tools used in NC machining. It has three major portions like other cutting tools, shank, body and cutting edge.

Prices of 5-axis CNC Machines

The purchasing cost of 5 axis CNC machine varies a lot. It can vary from one thousand dollars to five hundred thousand dollars. The price depends upon the size, features and type of CNC machine. Some important factors for price variation of 5-axis CNC machines are:

• Work piece material type i.e., whether it is steel, aluminum, titanium or others
• Design of the CNC machine like trunnion or swivel type
• Category of axis such as 3+2, 4+1 or full 5-axis CNC machine
• Size of the machine and other features like tool holding capacity and spindle power

Some simple comparison for the different types of 5-axis CNC machines is given below:

• 3+2 5-axis CNC milling machine can cost between $35,000 – 200,000
• Trunnion type 5 axis CNC milling machine costs around $200,000 – 500,000
• Swivel head type 5 axis CNC milling machine costs almost $150,000 – 500,000
• Mini 5-axis CNC milling machine prices vary from $3000 – 10,000
• 3+2 5-axis Small CNC milling machine can be purchased in a range of $25,000 – 40,000

Generally, the prices of 5-axis CNC machines are quite high but anyone who requires 5-axis CNC machine services can also get customized CNC manufacturing at hourly rates.

Custom Designed 5-axis CNC Machining Services

The need for 5-axis CNC machining has grown throughout the world due to its smooth finishing, accurate tolerance and less time-consuming. However, for low-volume manufacturing, the CNC machines can be very costly for purchasing and not getting the maximum of the CNC machine when there is not enough work, or you do not need it for a long time. So, large companies or manufacturers also provide CNC machining services. The services are charged on an hourly basis. The prices for per hour use of 5-axis machines may again vary on the type of CNC machine. However, the customer gets customized solutions and personalized parts manufacturing by attaining these services.  The price of a 5-axis CNC machining service can be from $50 to $200 that can be negotiated and directly deal with by the service-providing company.

Conclusion

5-axis CNC machining actually is different from 5-sided CNC machining. There are 5 different types of 5-axis CNC machines. From the professional point of view, multi-axis machining like 3+2 machining and 4+1 machining are either quite FULL 5-axis machining. What they can do is 5-sided machining. But 4+1CNC processing is more capable than 3+2 processing.