What is a 5-axis CNC Machine?

A 5-axis CNC Machine (also known as 5-axis Machining Center) is a precision CNC machine tool that uses a wide range of cutting tools to remove materials from a workpiece. It does so along five different directional axes, either by positioning the piece or by simultaneously cutting it along these axes, until the desired shape is achieved.

For a more specific representation, an example of a 1-axis machine would be a radial drilling machine, with up and down motion (Z axis). Following that same logic, a 3-axis CNC Machine can move up and down (Z axis), right to left (X axis), as well as forwards and backwards (Y axis).

A 5-axis CNC machine has two extra rotary axes which opens the door to an infinite number of machining possibilities. The types of rotary axis include rotary axes A, B and C which rotates around the X-axis, Y-axis, and Z-axis respectively. While these are three extra axes and not two, they’re still considered 5 axes in total. The combination of the additional axes is machine dependent and can come in any combinations of AB, AC or BC.

With the additional axes, the cutting tool can approach the part from all directions, enabling undercutting that is only possible on machines with fewer axes if the part was re-positioned with comprehensive fixtures. This situation in machines fewer axes is not only time consuming, but may present errors — situations which are avoided with a 5-axis CNC Machine.

The cutting tool of the 5-axis CNC Machine approaches the workpiece from any of the five directions. It moves across the X, Y and Z linear axes as well as rotate on the A, B or C axes.

Here are the corresponding axes and their movements:

• X axis – left to right
• Y axis – front to back
• Z axis – up and down
• A axis – 180° rotation around the X axis
• B axis – 180° rotation around the Y axis
• C axis – 180° rotation around the Z axis

One of the advantages of a 5-axis Machining Centre is that no complex clamping systems or fixtures are required to hold the part being machined. Hence, it is rather easy to set-up a work piece on such a machine.

The holding equipment or work piece part should preferably be mounted at the machine table center. The holding equipment can either be a zero clamp vice, a hydraulic clamp or just a block where the part to be machined is mounted securely.

More importantly, the part should be freely accessed by the cutting tool from all 5-sides and securely fixed such that it cannot move or vibrate. The cutting tools and tool holder need to then be prepared, measured and loaded into the machine’s Automatic Tool Changer (ATC) magazine.

An essential point often overlooked is the calibration of the entire machine before production starts. This calibration requires a very specific software and an automatic measuring probe (operated either by infrared or radio). The entire calibration function may take about 45-seconds (in the case of Hwacheon) or a maximum of 2-3 minutes, depending on the machine brand and type.

By running such a calibration cycle, the machine is freshly and correctly calibrated on all axes and no tolerances are accumulated between each axis. This should be done at least once a month (preferably once a week), and definitely before each production run.  

Many 5-axis Machining Centers are sold, unfortunately, without this function and the equipment necessary for it — mainly to save money. While initial sums of money may be saved, it comes at the cost of accuracy. Over time, such costs will be amplified, resulting in sub-standard machining. This is certainly not part of the industry’s best practices.

Another important point to note is to carefully check if there are any potential collision areas prior to pushing the cycle start button. Thereafter, allow the whole program to run, step-by-step, to ensure that every position is correct, and that every tool changed is the right one.

Without spending some time on checking, a crash may occur. This not only costs a substantial amount of time to fix, but may result in very expensive repairs as well as the need the for realignment of all axes.

One of the advantages of 5-axis machining (or 3+2 / 4+1 machining) is that it enables the use of shorter, and therefore more rigid cutting tools compared to 3-4 axis machining. This results in faster feeds and speeds, less tool deflection, and better cutting conditions.

These combinations allow quality surface finishes, better accuracy, heavier cuts, and fewer setups, all of which lower total cycle times. This ability is extremely useful in pocketing applications such as the milling of deep cavities in parts or dies and molds.

With modern automation solutions on 5-axis machines, the changing of tools can be easily automated. They include Hwacheon’s AWC (Automatic Workpiece Changer) or APC (Automatic Pallet Changer) systems which can turn machine tools into FMC (Flexible Manufacturing Cell) Systems. With that, “High Mix – Low Volume” production — a very efficient manufacturing technique — becomes a reality.

With respect to tooling and the number of tools being used, larger ATC magazines provide a significant advantage when machining very complex parts. A standard magazine of 30-40 stations will be limited very quickly. Hence, a 5-axis CNC machine with 60 tool stations is recommended. If the parts are very complex and automation systems are added to the machine, an ATC with 60 stations is a must, though 120 stations would be even better.

Not only will this functionality provide a sufficient number of various and different toolings, it will also allow “sister” tools to be integrated. Such tools have the exact size and specification used for a specific operation with the tendency to wear out faster than other tools. Sister tools will be replaced automatically, as soon as the life time of the other tool, with the same specification, is running. This will avoid working with a weakening tool or tool breakage.

Perhaps the main advantage of Multi-Axis Machining Centers is that more surfaces and part sides can be approached in the same setting / clamping than simpler machines. Multiple operations (milling, drilling, tapping, etc) can also be done without the need to re-clamp the part into a secondary position (or even to move the part to another machine).

Not only will time be saved and fixture cost be avoided, errors are eliminated too. This reduces the need for additional machines or manpower.

Pros of 5-axis CNC Machine

Keys benefits of a 5-axis CNC Machine:

1) Minimized Machine Setup

With a single set-up process (aka “Done-in-One”), you can significantly reduce preparation time and increase both human and machine efficiency. This also reduces human and machine errors which result from working on multiple set-ups for each stage of machining. The simpler clamping equipment used to place the part in the required position in the machine also saves time, cost and reduces potential errors.

2) Machine Complex Shapes

With 5-axis machining, complex shapes and designs can be easily handled. This may include the following: parts of hydraulic systems, water pump housing, gear box housing, gear wheels, injection molds, oil & gas equipment, medical or blood transfusion equipment and many others.

3) Higher Machining Accuracy

By reducing the number of manual settings required, 5-axis CNC machine can help to improve the overall accuracy of the produced part.

4) Better Surface Finish

With a 5-axis CNC machine, the cutting tool can not only move closer to the workpiece, but also be positioned 90° to the part surface — this allows optimum cutting conditions at any time. The fourth and fifth axes (which are the rotational axis) allow shorter cutting tools that vibrate less, resulting in an improved surface finish. The main objective of the additional axis is to allow the cutting tool to reach all 5 sides on the part more precisely.

5) Faster Material Removal

Specifically designed to remove even toughest materials quickly and efficiently, a 4+1 or full 5-axis CNC Machine will significantly reduce any manual effort. This leads to greater efficiency and stability in machining.

6) Significant Time Savings

It is becoming more and more important to look into operation and manpower cost, given the rising costs of manpower, the lack of trained manpower and the need to increase factory productivity. Thanks to the all-in-one setting in such machine tools, operators do not have to re-clamp and move the parts to other machines for the next operation. Instead, they can focus on managing additional machines, hence increasing their productivity.

7) Significant Cost Savings

Improved tool life results in a lower frequency of replacement of new tools. Improved accuracy lowers the risk of costly mistakes or scraps. 5-axis CNC Machines further reduce floor space requirements, increases flexibility and spindle usage, decreases need for costly fixtures and lowers the overall inventory investment — all of this adds up to cost savings.

8) Expand Factory Capacity and Production Flexibility

For part manufacturers and contract manufacturers, investing in a 5-axis CNC Machine improves the flexibility of your productions. With its multiple applications, such machine tools allow you to maximize your machines for both large and small manufacturing orders. Such capabilities may not be present with lower cost standard machines that have clearly limited capabilities. 5-axis CNC machines are also ideal for today’s High Mix – Low Volume manufacturing environment, where mass production is less common than delivering machined parts in smaller batches which are repeated if the requirement arises.

9) Fewer Competition

5-axis CNC machines can significantly improve both your productivity and profitability. They set your manufacturing capability several notches above your competitors as they have ability to undertake a wider range of complex jobs with improved product quality, as well as catering to upcoming production demands.

Cons of 5-axis CNC Machine

Naturally, there are some drawbacks to a 5-axis CNC Machine. Here are some of the common disadvantages:

1) Costs

A 5-axis CNC machine and the essential software often requires an initially higher investment. The total cost of investment is often higher than the cost of standard 3-axis Machining Centers. Moreover, the maintenance required is often more complex.

2) CAD / CAM Programming

In addition to the three linear motions, there are two additional rotational motions involved, making 5-axis machining more complex than 3-axis machining. Consideration is also needed on the coordination of the motion of each axis, to avoid interference, collision, and the appropriate amount of interpolation motion.

To optimize the required machining precision and surface quality, complex programming may be a challenge, which may require the service of a qualified programmer.

3) Advanced Operator Skills Required

5-axis machining is an advanced technology where the programming, setup and machine operation require higher skilled technician.

From the above points, you can see that the benefits of using a 5-axis CNC machine tend to outweigh the cons. However, you should still consider the range of challenges posed when buying a 5-axis CNC machine. To avoid making expensive mistakes, consider undertaking a comprehensive review of your machining requirements before investing in such a machine tool.

In today’s challenging production and manufacturing environment, the absence of such highly flexible machining centers puts your machine shop at a significant disadvantage.

(You can request for our 5-axis Machining Centre catalogue or fill up the contact form for a consultation.)

To choose the best 5-axis CNC machine tool suitable for your shop floor, you need to carefully go through its various features.

Use the following as a checklist when you are selecting a 5-axis CNC machine for your factory:

1) Capacity to Produce Complex Parts

• Head / Head rotary axes and 2 rotary axes are situated at the head structure. The 5-axis are made up of the 3 linear axes and the 2 rotary axes at the head.

• Hwacheon’s Double Column Large Sized SIRIUS-2500/5AX is an example of such a 5-axis Machining Centre. Its 3 linear axes (X – Y – Z) provide linear movements while the “Forkhead” provides the 2 rotational axes. The 5 faces of the part can be reached and all 5 axes can be moved simultaneously, if required.

2) Ability to Consistently Revolve

• Table / Head rotary axes have one rotary axis situated on the table and the other one at the head.
• The revolving axis located at the head has a restricted range, while the rotary shaft found on the table does not have a limited scope.
• Such configurations have certain advantages for specific applications. E.g. Shaft machining—long cylindrical parts where operations need to be done around the part (milling, drilling, tapping, etc). This is used on standard Vertical Machining Centers (Vesta Line, Sirius Line) or Long Bed Travelling Column Machining Center Hi-Rex 4000 / 5000 / 6000).

3) Defined Work Envelope

• Table / Table rotary axes – 2 rotary axes are combined into a Trunnion Table. Eg. Hwacheon D2-5AX, M2-5AX, M3-5AX, M4-5AX.
• Restricted travelling scope in one of the revolving axes, while the other axis has no limitation on rotation.
• This is widely used for complex precision parts or for Mold & Die applications.
• Rigidity is good for most application requirements.
• The speed of the 2 rotary axes varies and is subject to the design and structure. Dynamic version for higher speed and dynamic, mainly for contour machining. Rigid and slower in movements are for heavier and more stable cutting conditions.
• Overall, the different usage and applications will define which configuration is most suitable. Each configuration and design has its own advantages and limitations.

4) Adequate CNC Processing Power

• Processing power of the CNC control has to be high enough to compute, calculate and control the number of axes used at the same time.
• The block processing time / rate is even more important at 4 or 5-axis movements as the amount of data increases drastically.
• For a 3+2 configuration, it is not that critical as at any given time, only 3 axes will work simultaneously together.
• For a 4+1 configuration, the amount of data to be processed is much higher and requires faster block processing time.
• For a full 5-axis version, where all 5 axes can be moved simultaneously, the block processing time is crucial. If it is not fast enough and the feed rates programmed at a higher rate, the machine may start jerking or slowing down.

5) Match Look Ahead Function to Application

• Standard machines with FANUC 0i-MF CNC control come with very low settings of 40 blocks look ahead and a BPT (Block Processing Time) of only 4 msec.
• A minimum of 200 blocks is required for a 4+1 axis machine used for part machining with a BPT of 2 msec.
• 400 blocks are recommended for more complex 4-axis machining operations / sequences with a BPT of 1 msec.
• For a full 5-axis simultaneous operation, a much faster calculating CNC control is of course required. This could be the Fanuc 31i B5 with HAI 600 block look ahead and a BPT of 0.4 msec, or optional 1000 block look ahead function and the same 0.4 msec BPT, providing very high calculation speed for even the most complex operations.

6) Sufficient Power and Rigidity of Machine Spindle

• To ensure smooth and error-free cutting, the machine spindle must be powerful enough to handle the stresses and loads imposed on it as well as have sufficient reserves to the limit.
• A less powerful spindle of 11-15Kw with a maximum torque of less than 100Nm may limit the machine’s capabilities.
• Hwacheon’s new 4+1 or full 5-axis Machining Center D2-5AX is specially mechanically designed from the beginning to handle a spindle power of 37Kw and up to 310Nm torque.
• Although the initial machine cost may be higher, its wide range of applications and long-term savings will prove to be more cost effective over the long-run.

7) Suitable Tool Holder System

• The best tool holder system to be used is either BBT or HSK to eliminate vibration, which decrease tool life, can affect surface qualities and at the final end destroy the spindle bearings.
• They provide the best connection / bonding between the spindle and tool holder at any time and under any machining condition.
• Note: a medium sized HSK-A63 tool holder provides 2.5 times more strength and rigidity compared to a standard BT 50 holder.

8) Adaptable Cutting Feed Rate and Conditions

• It is important to have the flexibility in maintaining a constant cutting feed rate speed or to vary it for various cutting conditions. This allows better control of each situation to optimize the cutting feed rate.
• Hwacheon has developed its HECC (Hwacheon Efficiency Contouring Control), HTLD (Hwacheon Tool Load Detect) and OPTIMA (Hwacheon Cutting Feed Optimization System) software for such purpose. This machining software package is delivered as a standard for every Hwacheon 5-axis Machining Center.

9) High Machine Tolerance and Durability

• Consider the mechanical design and mechanical built / construction of the machine, as well as the use of electronic systems for optimization and calibration.
• Hwacheon invests in rigid mechanical designs and construction methods.
• To ensure greater longevity and tolerance, all our machine parts are casted in MEEHANITE to ensure mechanical superiority in our machines.

10) Spindle Heat Control and Cooling Management

• It is essential that the spindle housing, including the spindle nose, are effectively cooled and best in sections.
• This helps to prolong the longevity of this vital component, providing better quality and accuracy for the parts.
• Hwacheon’s cooling system is defined in segments, ensuring a controlled temperature at any time.
• Hwacheon also uses an Oil-Jet bearing lubrication and cooling system, which prevents the bearings from being overheated and ensures that fresh oil runs into the bearings at any time. This guarantees that operational cutting runs 24/7 at maximum spindle speed do not become an issue.

11) Horizontal or Vertical

• Horizontal 5-axis CNC Machines are usually equipped with an automatic pallet changer (APC) ready to be installed on the shop floor. They tend to be heavier and more rigid, which supports cutting steel, titanium, or Inconel materials. Designed to have effective chip disposal, the high volume of chips will naturally free fall into the conveyor.
• Vertical 5-axis CNC Machines, on the other hand, tend to be more agile for processing smaller parts. The vertical clamping of parts is found easier and more convenient by operators. Although they enable better operator access and easier process monitoring, such machines need to be carefully designed for effective chip removal.

12) Swiveling-Head or Trunnion Table

• The non-tilting table on a swiveling-head machine is often preferred for holding big and heavy parts, because this type of table offers better rigidity.
• They also tend to be more versatile, lending themselves to using multiple fixtures, vises or tombstones.
• The swiveling head as well as trunnion style version enables the use of shorter tools, as all reachable areas and points on the part can be reached at the shortest distance by the spindle.
• The trunnion style table machine is also preferred in mold making as both rotary axes are contained in the trunnion table itself, and the spindle head is stationary.
• The spindle head reaches out over the tilting table, providing better undercut capabilities as well as access to the underside of the part.
• Trunnion table machines tend to be more effective in heavy chip removal.

The prices for a medium size 5-axis Machining Centre (table size diameter 600mm) can vary between US$180,000 to US$450,000 (or even US$600,000 in some cases), depending on various factors:

1. Machine Size & Specifications

• Table size
• X – Y – Z axis
• Spindle power
• CTS requirement (Coolant Through Spindle)
• Number of tool positions required in the ATC (Tool Magazine)
• Other required specifications

2. Types

• 5-axis is defined in 3 categories with price variations:
  • 3+2 axis
  • 4+1axis
  • Full 5-axis

3. Design

• Most 5-axis CNC Machines have 3 linear axes and 2 rotational axes which are provided by a so-called “Trunnion” table.
• A designed and built-in 5-axis machine provides better stability and accuracy, but investment will be higher.
• A cheaper version is to add a 2-axis table on top of the table of a 3-axis Machining Centre.
  E.g. Modular and flexible, the VESTA-1000+ Vertical Machining Centre can be installed with a NC Rotary Table to allow 3+1 Axis simultaneously controlled operations. If a 2-Axis table is added, the VESTA-1000+ allows 4+1 Axis production.

4. Materials to be Machined

• Aluminum
• Standard Steel
• Stainless Steel
• Titanium
• Inconel
• Others

Variations in price are more evident when defining the application of the machine. A machine for part machining has a lower criteria compared to a machine used solely for Mold & Die applications or handling tough materials (e.g. Titanium, Inconel, Stainless Steel). The material which the machine should cut will also define the quality, stability and rigidity of the overall machine design as well as the spindle power, torque and built.

Aluminum or Standard Steel materials require a machine with more basic and standard specifications. Whereas materials such as Stainless Steel, Titanium or Inconel will require machines with the highest specifications and built. Mold & Die applications, especially for higher quality molds, will require very high machine specifications due to higher precision and accuracies.

It is highly recommended to facilitate a clear and open discussion between the end user and an experienced machine tool supplier. Indeed, low-cost equipment alone cannot guarantee quality products or higher profits.

With over 75 years of experience as a pioneer in CNC machine tool manufacturing in South Korea, Hwacheon uses its strengths to design, test and refine some of the best 5-axis machining techniques in the trade.

We provide a total machining solution for complex work pieces which require high precision and multiple production processes with just a single setting — from tool selection to the final product.

Our series of full 5-axis Machining Centers are made to fulfill demands for very complex shapes and contours, such as producing parts used in aerospace or marine industries, or catering to the high standards of mold & die manufacturing. They are also solidly built to handle modern tough materials such as Inconel, Titanium or Heat Resistant Stainless Steel.

5-axis CNC Machines Made by Hwacheon

Here are some of the best-selling models of 5-axis CNC Machines proudly made by Hwacheon.

1) D2-5AX / D3-5AX

The newest design for 4+1 or full 5-axis applications that offers a cost-effective solution to a very wide range of applications and materials. Compactly designed, the D2-5AX / D3-5AX are easily automated mid-sized 5-Axis Machining Centers, ideal for “High Mix- Low Volume” production. The heart of this range is the 37Kw direct drive motor spindle.

2) M1-5AX / M2-5AX / M3-5AX / M4-5AX

Hwacheon’s series of full 5-axis Machining Centers are made to produce even the most complex shapes and designs. Designed to cater for the high standards of mold & die manufacturing or to fulfil demands for very complex shapes and contours. These are also suited for producing the parts used in aerospace, marine or optical instrument industries.

Our top range model M4-5AX is designed for special applications – it is built for the effective machining of extreme materials like Inconel, titanium or heat resistant stainless steel. The machine’s Z-axis is designed with solid box-guideways to ensure the enormous power of the spindle is kept in control even under the most critical cutting conditions. Designed and built by Hwacheon, the 2-Axis trunnion table uses large dimensioned roller gear drives for its A + C axis as well as an effective cooling system.

3) SIRIUS-2500 5AX / SIRIUS-3000 5AX

In these models, the machined part is clamped on the large table (X-axis) while the machine head provides Y & Z plus A & B axis. As a Double Column Machining Center, Hwacheon SIRIUS-2500 5AX / SIRIUS-3000 5AX  are mainly used for larger parts or molds. For such applications, a machine with a trunnion table would become too large and costly to build.  If you wish to machine larger parts of a certain size and part weight, it is recommended that you use a 2-axis milling head.

To learn more, do fill up our contact form to arrange for a consultation at your convenience.