To better support the increasingly sophisticated needs of advanced industries like aerospace engineering, medical, defence, robotics and automotive manufacturing, CNC machine tool makers have constantly innovated in developing newer and more powerful machine tools.
One of the major milestones in this area is the development of 5-axis CNC machine tools. Also known as 5-Axis Machining Centres, the capability and flexibility of such machines are far superior to standard 3-Axis Machining Centres.
To help you to decide if 5-axis CNC machines are relevant for your production, this article will cover the following commonly asked questions regarding this technology:
- What is 5-Axis CNC machining?
- When do you need a 5-Axis CNC machine tool?
- What are the advantages of 5-Axis CNC machining?
- What should you look for in a 5-Axis CNC machine tool?
- Types of 5-Axis CNC machine tools available from Hwacheon
#1 What is 5-Axis CNC Machining?
5-axis CNC machining techniques employ a Computer Numerical Control (CNC) machining centre to position or synchronise a part in 5 different axes for easy reach of cutting tools. This allows the part to be machined with three primary axes – X, Y, and Z – as well as two additional rotating axes (A and C or B and C).
Please see the diagram below to see how it works.
Controlling the movement of a part across multiple axes gives the cutting tool the flexibility to be multiple-directional. It can thus reach across most angles, even negative ones, and make fuller use of standard cutting tools across a wider range of shapes and dimensions.
3+2 Axis Versions
In the 3+2 axis version, any 3 of the axes can be simultaneously controlled while the remaining 2 axes are used for positioning the piece.
Here’s how it works:
- You can use X & Z & C together, while Y & A axes are used for positioning.
- You can use Y & Z & A together, while X & C are then used for positioning.
4+1 Axis Versions
For the 4+1 axis versions, any of the 4 axes can be simultaneously controlled while the remaining 1 axis is used for positioning.
Here’s how it works:
- You can use X & Z & A & C together, while Y is used for positioning.
- You can use X & Y & Z & A together, while C is used for positioning.
Full 5-Axis Versions
Finally, there are the full 5-axis versions where all 3-axis (linear) and 2-axis (rotational) can be simultaneously controlled.
In this version, the axes are configured in 3 linear axes (normally called X, Y & Z), and two rotational axes (normally called A & C). The A-axis is the tilting axis while the C-axis is the rotating axis. In such a configuration, there will usually be a table surface where the work piece is mounted on.
For 5-axis CNC machine tools with a Trunnion table, the table provides the tool with two rotational axes:
- A-Axis – Table surface swivel (tilt) towards the operator or away from the operator (eg Hwacheon’s M2-5AX, M3-5AX, M4-5AX. On the D2-5AX, the table surface tilt to the left or right side from the operator’s point of view).
Depending on the model, a wide range of tilting angles can be achieved. Generally speaking, machines with a wider tilting range of +/- 120° (like the M3-5AX and M4-5AX) are exceptional. Such table designs and available ranges can tilt the workpiece to provide access to even more complex angles.
In the case of models like the D2-5AX, the table is mounted lengthwise in view from the operator, and provides a tilting range of +30° to the right and -110° when tilting to the left.
- C-Axis – Table top surface (part is mounted on it) rotate either left (clockwise) or right (counter clockwise). The rotation can be to a maximum of 360° providing a full circle without the need to go back to zero position again. This allows the part to be positioned at any required rotational position. The 3-linear axis provide the possibility to position linear movement to the required position. The tilting axis provides the angles to the required tilted position.
Together with the 3 linear axis (X, Y and Z) and the rotating A-Axis and C-Axis of 5-axis machines, the part to be machined can be manoeuvred and moved to the most ideal angles and positions for cutting.
#2 When Do You Need a 5-Axis CNC Machine Tool?
Given their greater flexibility and adaptability, 5-axis machine tools are useful for a wide-range of machining operations across multiple industries for specific machining needs.
Here are 7 of the most common applications.
1) When Cutting, Drilling or Tapping Operations are needed on all 5 Faces with Specific Angles
5-axis machining is most prevalent in the aerospace, medical, automotive, general part, mold and die, or oil and gas industries, just to name a few. These parts tend to be unusually shaped, have complex contours and surfaces, or have surfaces, locations and positions with specific angles. They include aircraft or ship turbines, impellers, and parts like steering knuckles which require operations on all 5 faces and additional specific angles.
2) When You Need More Flexible Engineering Solutions
Simultaneous 5-axis machining operations are common in mold and die as well as aerospace part manufacturing industries. With the ability to position or move the part in various axis, 5-axis machine tools provide design engineers with greater freedom to design even the most difficult shapes and form. Therefore, parts to be worked on can be more complex, resulting in better overall engineering solutions across practically all industries.
3) When You Need High Volume-Low Mix Production4) When You Receive Orders for Complex Shaped Workpieces
5-axis machining is ideal for companies which require highly complex and precise workpieces like the aerospace, medical, automotive, oil & gas, semiconductor, and electronic industries. Manufacturers in these sectors need both the right know-how and the right equipment to support them in producing parts with accuracy and lasting constant performance.
With the right machine, good CAD / CAM, toolings and trained operator/programmer, such manufacturers can make their production profitable while setting themselves apart from standard manufacturing companies.
5) When You Want to Reduce Lead Time and Increase Efficiency
With standard and fewer clamping fixtures needed to manufacture even the most complex parts, 5- axis CNC machine tools replace the need to move your part to multiple machine tools with just one machine. The ability to do single setup machining offers significant business advantages, especially as lot-sizes shrink while parts become more complex.
6) When You Want to Improve the Quality and Accuracy of Your Part
By eliminating the need for multiple setups of various machine tools, human and machine errors are reduced. This improves the accuracy of your machined part when you use the features of 5-face and 5-axis machining in a single setup. Such machines also allow the use of standard tools. This can translate clearly into cost-savings as no special tools are required (eg very long tools or form-tools).
7) When You Want Greater Flexibility, Production Speed and Accuracy
While a 3+2 axis configured machine tool is an improvement over standard 3 and 4 axis machines, a 4+1 designed machine provides even better flexibility – it is estimated that 4+1 machines can produce 85% of all parts required by any industry. This is a boon for part manufacturers who have to cater for all kinds of work and can’t be too selective. A 3+2 axis machine (usually a standard 3-axis machining centre with an optional 2-axis table added) requires each new tool at start position, and are limited in part size and machining complexity. A full 5-axis simultaneous machine is needed for very complex shapes such as turbine wheels, tire- mold sections, human spare parts, etc. These are estimated to cover the remaining 15% range of all needed parts, i.e. it can cover 100% of standard to complex machining needs.
#3 What are the Advantages of 5-Axis CNC Machine Tools?
With simultaneous 5-axis machining, your CNC machine tool can work on extremely complex contour surfaces which are challenging or even impossible to produce with simpler machine tools. Machining around the 5 sides of a part in a single setup means you can perform operations on all 5 sides of a part in a single setup, saving you preparation time, re-clamping and effort.
Beyond that, 5-axis machining increases your flexibility and accuracy as you can eliminate the need to move workpieces across multiple machines. This further reduces the need for various clamping fixtures and set-ups.
Here are some of the advantages that you can enjoy with this technique of machining.
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) Ability to Manage Complex Designs
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 amount of manual settings required, 5-axis machining will help to improve the overall accuracy of the produced part.
4) Better Surface Finish
5-axis machines built with higher mechanical quality, such as Hwacheon M2-5AX, M3-5AX, M4-5AX and D2-5AX machining centres, provide the basis to achieve reduced vibrations, smoother high-quality surfaces and constant accuracy. Your machine operator need not re-clamp the part as it remains clamped during the whole machining cycle. This greatly improves the quality of finishes.
5) Faster Material Removal
Specifically designed to remove even toughest materials quickly and efficiently, a 4+1 or full 5-axis CNC machining centre 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) Expand Factory Capacity and Production Flexibility
For part manufacturers and contract manufacturers, investing in a 5-axis machining centre improves the flexibility and nimbleness of your productions. With its multiple applications, such machine tools allow you to maximise 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.
In short, 5-axis CNC machine tool can significantly improve both your productivity and profitability. Plus, they set your manufacturing capability apart from your competitors.
#4 What to consider in a 5-axis CNC Machining Tool?
Now that you have learned about the advantages of a 5-axis machining tool, the next question is this: How do you choose the right 5-axis CNC machine tool?
To help you to do so, we’ve provided a handy checklist for you to consider.
1) Adequate CNC Processing Power
Ensure that the processing power of the CNC control is high enough to compute, calculate and control the number of axis used at the same time.
2) Match Look Ahead Function to Machine Type
The look ahead function for a 4+1 axis machine should be a minimum of 200 blocks. For more complex 4-axis machining sequences, 400 blocks would be better. For a full 5-axis simultaneous operation, a faster calculating CNC control is required. This could be the Fanuc 31i B5 with HAI 600 block standard, or optional 1000 block look ahead function, providing very high calculation speed.
3) Sufficient Power and Rigidity of Machine Spindle
Sufficient power and rigidity of the machine spindle are an important factor and is often overlooked. However, a powerful spindle requires the support of an even more rigid mechanical design. To ensure smooth and error-free cutting, the heart of the 5-axis machining centre – the machine spindle – need to not only be powerful enough to handle the stresses and loads imposed on it but have sufficient reserves to the limit. Subject to the material to be machined, a less powerful spindle of 11-15Kw with a maximum torque of less than 100Nm may limit your machine’s capabilities. Such machines may be cheaper in the short run, but not with a longer view.
(Hwacheon’s new 4+1 or 5-axis machining centre D2-5AX is specially mechanically designed from the beginning to handle a spindle of 37Kw and 310Nm torque. While this may lead to higher initial machine cost, its wide range of applications and long-term savings will prove to be more cost effective. All Hwacheon spindles are direct drive systems without belt, and are designed and made inhouse.)
Check that the tool holder systems used are either BBT or HSK to eliminate vibration. They should provide the best connection between the spindle and tool holder at any time and under any machining condition.
5) Ability to Adapt Cutting Feed Rate and Conditions
Depending on your machining needs, you may wish to maintain a constant cutting feed rate speed or vary it for various cutting conditions. In this context, you’ll need a machine that can better control each situation to optimize the cutting feed rate.
(To do so, Hwacheon has developed its HECC (Hwacheon Efficiency Contouring Control), HTLD (Hwacheon Tool Load Detect) or OPTIMA (Hwacheon Cutting Feed Optimisation System) systems.) This machining software package is delivered as a standard for every Hwacheon machining centre.)
6) High Degree of Machine Tolerance and Durability
To ensure that your machine tool delivers high degrees of tolerance and durability, you should consider how it is constructed and designed.
There are usually two stages here:
- The mechanical design and mechanical built / construction of the machine
- The use of electronic systems for optimization and calibration Beware of low-cost tool manufacturers that scrimp and save on the mechanical aspects of the design, and use electronic systems to compensate their weaknesses.
(Hwacheon invests in rigid mechanical designs and construction methods. We cast more parts to ensure mechanical superiority in our machines, ensuring that they have greater longevity and tolerance.)
7) Spindle Heat Control and Cooling Management
As the heart of any CNC machine – particularly for a 5-axis CNC machine tool – it is important to manage heat control in the spindle and the frame. Doing so not only helps to prolong the longevity of this vital mechanism; it’ll also provide better quality and accuracy for your parts. To prevent overheating of the spindle, it is critical that the spindle housing as well as the spindle nose are effectively cooled. Heat prevention is necessary during intensive machining work, to reduce and control the heat generated from motor and the bearings during higher speeds and longer machining cycles.
Remember that a built-in spindle has the motor operating inside the spindle housing. Thus, it is essential that the spindle housing, including the spindle nose, are effectively cooled in sections. Hwacheon’s cooling system is defined in segments – thus, the cooling medium never becomes “hot.” This ensures a controlled temperature at any time. Secondly, and most importantly, Hwacheon uses an Oil-Jet bearing lubrication and cooling system.
This not only prevents our bearings from being overheated, but ensures that fresh oil is run into the system at any time. Contrast this to what some manufacturers use: grease pack or air-oil lubricated spindles. These will not provide a secured temperature condition for bearings.
#5 What are the Types of 5-Axis CNC Machine Tools available from Hwacheon
As you can see, there are many factors to consider in 5-axis machining. From the techniques used to the types of tool available, the choices can be bewildering for first-time buyers. From our close to 70 years of experience as a pioneer in CNC machine tool manufacturing in South Korea, we have focused our strengths on designing, testing and refining the best 5-axis CNC machine tools in the trade.
VESTA-1000+ Vertical Machining Centre – 3+1 Axis or 4+1 Axis
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.
Capable of producing smaller complex parts effectively (subject to table used and other options), the VESTA-1000+ help factories with their 4+1 machining jobs. However, it is not a substitute for a designed and build 4+1, or a simultaneous 5-axis machining centre.
D2-5AX – 5-Axis Machining Centre
Compactly designed the D2-5AX is an easily automated mid-sized 5-Axis Machining Centre, ideal for “High Mix- Low Volume” production.
Key advantages of D2-5AX :
- Its B-axis swivels towards the right and left side (seen from operator in front of the machine)
- True 0 is achieved when the table surface is horizontal positioned.
- The table can move through a range of -30 (table surface points to the right) to +110 (table surface points to the left)
- Rotating C-axis has a complete circular motion of 360 all around.
Hwacheon’s series of full 5-axis machining centres are made to produce even the most complex shapes and designs. Designed to cater for the high standards of mould & die manufacturing or to fulfil demands for very complex shapes and contours and for producing the parts used in aerospace or marine 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. With a built-in spindle with up-to 55Kw power, it provides up-to 1009Nm torque and 8,000rpm, with an option for a 12,000rpm spindle with 420Nm.
The machine’s Z-axis is designed with solid box-guideways to ensure the 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. With an overall weight of up-to 28,500Kg, the M4-5AX is a machining powerhouse that is not easily available in the market.
SIRIUS 2500-5AX – 5-Axis Double Column Machining Centre
In this model, the machined part is clamped on the table (X-axis) while the machine head provides Y & Z plus A & B axis. As a double column machining centre, the Hwacheon SIRIUS 2500-5AX is 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.
We hope that this comprehensive article on 5-axis machining and the machine tools available for such jobs is useful.
A 5-Axis CNC machine tool offers factories the opportunity to undertake jobs which they were previously unable to fulfil. For manufacturers that currently use 3-Axis machining, the progression to a 4+1 or even full 5-axis machine may be the next logical step in your production and investment planning.
Due to the cost of such machines, however, it is advised that you fully understand which processes best meet your specific production needs. You need to also choose the right CNC machine tool to fully realise the efficiency and profitability of your production.
If you wish to know more about 5-Axis machining, contact us for a discussion. We will be happy to advise you on which technology best meets your production needs and targets.