CNC machining has changed the manufacturing process by automating cutting, drilling, and turning. It is extremely accurate and produces parts of better quality than manual methods. Among multi-axis machines, 3-axis and 4-axis machines are most commonly employed. 5-axis machining is a modern advancement with additional axes. Choosing between 3, 4, or 5-axis CNC machining can be difficult for professionals. Keep reading this article to understand the differences between all the types and their usability.
Comparison Between 3-Axis Vs, 4-Axis, Vs 5-Axis CNC Machining
The major technology behind all types of CNC machines, including 3-axis, 4-axis, and 5-axis, is the same. However, their capabilities are unique and distinct. The primary difference lies in the axes’ movement. The axis type of CNC machines determines the complexity and quality of the parts. Let’s learn the differences in detail:
Axes of Movement
The primary distinction in these machines is the number of axes of movement. With more axes, the cutting tool can move in more directions. With 5-axis CNC machines, the cutting tool can move in the most complex way.
Part Complexity
CNC machines have more axes; therefore, the cutting tool has access to more angles, which means that machines with more axes can accommodate more detailed components. As such, 5-axis machines are the best option for complex designs.
Positioning
The greater the number of axes a machine has, the more positioning options the machine will have. A 5-axis machine will offer the most flexibility compared to a 4-axis machine, and a 3-axis machine will provide the least number of positioning options.
Programming
Because 5-axis machines have more complicated machining paths than traditional 4-axis CNC machines, a more complex program is required to control movement in all of those directions, along with more variables to control. Besides, a 4-axis CNC machine needs more complex coding than a 3-axis machine.
Time Taken
The fastest of the machines are the 5-axis machines. They can finish parts quickly because multiple cutting tools are working on the part at the same time. The 3-axis machines are the slowest, and the 4-axis machines are between the 5-axis and 3-axis machines.
Operator Training
The setup of 5-axis and 4-axis CNC machines is complex. Therefore, an operator needs a particular expertise to work with them. A 3-axis CNC machine can be used even by a person at a lower skill level. Skilled operators for 5-axis CNC machines also have high salaries due to their skill level. Less skilled operators can operate a 5-axis CNC, but they less skilled operators will not be able to utilise the machine fully.
Customization
5-axis machines provide more customisation options. The cutting tool is freer, and the part can be changed in many ways. But with 3-axis machines, the parts are less flexible. Modifying parts usually involves changing the position of the workpiece and requires moving the workpiece.
Material Management
Some difficult-to-machine materials can have accelerated tool wear due to 3-axis machining. One major advantage of 4-axis and 5-axis machines is that they can work through multiple angles. The unique workability offers low wear and tear even with hard materials that require touch machining.
Tool Breakage
More axes (4-axis and 5-axis) offer more possibilities for tool approach angles, which allows a shorter tool to be used, increasing accuracy and decreasing tool breakage. The 3-axis CNC machine is only able to approach its workpiece perpendicularly, which often leads to higher tool breakage rates.
Tool Collision
Five-axis machines require more complex programming, so any small mistake can cause the tools to hit the workpiece. A collision of tools will be less likely with 3-axis or 4-axis machines. The modern replication aspects of CAM software offer a low probability of tool collision.
Secondary Finishing
As 5-axis machines can work on the material from different angles, they offer better accuracy and a shiny finish. However, 3-axis and 4-axis CNC machines usually need a round of finishing after the part is manufactured. Finishing enhances the surface finish and quality of parts.
Error Accumulation
3-axis machines will only let you work on one face of your workpiece, so you’ll need multiple setups. Each time you set it up, you introduce some error, and the error from a setup is compounded with each successive setup. 4-axis and 5-axis machines are more flexible and can create accurate parts in a single setup. This avoids compounding errors with measuring and setup.
What is 3-Axis CNC Machining?
3-axis CNC machines, including lathes and mills, move along 3 axes. The X-axis and Y-axis are the left/right and front/back movements, while the Z-axis is the up and down movement. A CNC tool can move in both horizontal (across the X-Y axes) and vertical (the Z-axis) directions, allowing the operator to control how deeply the cutting tool will cut, in different XYZ angles.
The machine can cut and plan to an exact depth, depending on the tool and material. However, the motion is limited and doesn’t automatically rotate the workpiece. Therefore, this type of machine is generally limited to basic and simple parts with plain shapes and little, if any, detail. 3-axis CNC machines are effective for making 2D parts and 2.5D parts, which are effective for shorter production runs. They are also less expensive than other CNC machines, which makes them ideal for startups or small to medium-sized businesses.
Benefits of 3-axis CNC Machining
- Cheaper: The 3-axis CNC machines have a lower cost than other types. Thus, they provide an affordable solution for product manufacturing needs.
- Ease of Use: Working with a 3-axis machine is easier than ones with more axes. Learning it does require special training and complex methods.
- Simple Programming: The coding for 3-axis CNC machining is not complex. Even a few changes in the code can do a great job for product changes.
- Low Maintenance: The components produced through 3-axis machining are not intricate in shape and are robustly constructed. Therefore, a small amount of maintenance and precision is sufficient.
Drawbacks of 3-axis CNC Machining
- Slower Production: 3-axis CNC machining is quicker than manual options. However, it is slower than most machines with a higher axis count.
- Limited Geometries: These machines will not be able to create parts with complex shapes or geometries.
- Probably Slower Production Rate: Parts are likely to require realignment for all machining to be complete, making manufacturing slower.
- Single-Side Machining: 3-axis CNC can only machine one side at a time in a setup.
- Less Precision: More setups can reduce the precision achievable with 3D CNC.
What is the Usability of a 3-axis CNC Machine?
- Lower Cost: 3-axis CNC machines are the best choice when cost factors are paramount. They are cheaper to purchase, and upkeep is also less expensive.
- Low Production Quantity: These 3-axis CNC machines are perfect for low-volume production because they are easy to set up and low-cost.
- Simple Design: When manufacturing parts with simplified designs, 3-axis CNC is best. The parts come with simple designs and less attention to detail.
What is 4-axis CNC Machining?
4-axis CNC machining – also referred to as 4-axis machining – is a multi-axis approach that utilises a CNC machine with one additional rotary axis. In 4-axis CNC machining, the machine has movements in 4 directions. Besides, it uses the three linear axes: X, Y, and Z, with an additional axis called the A-axis.
The A-axis rotates around the X-axis. This extra movement allows the machine to process more elaborate parts and mill at angles that 3-axis machines can’t process. In short, 4-axis CNC machining adds a rotating A-axis to the standard X, Y, and Z axes and allows the machine to perform things that can’t be done with a 3-axis.
Benefits of 4-axis CNC Machining
- Multi-Sided Machining: A 4-axis CNC is capable of machining parts on all four sides of a workpiece in one setup, thus eliminating the need for multiple setups.
- Less Expensive Machining for Greater Volumes: A 4-axis machine provides a less expensive overall cost for large production volumes because you rely on fewer setups than a 3-axis CNC.
- Precision: Using fewer setups allows for tighter tolerances.
Drawbacks of 4-axis CNC Machining
- Increased machine costs: 4-axis CNC machines are costlier than 3-axis machines.
- Expensive fixtures: Fixtures for a 4-axis CNC machine can also be more expensive, particularly for simple machining that only machines on one face.
- Limited speed: While 4-axis machines might have increased speeds over 3-axis machines, their speed is limited compared to 5-axis machines.
What is the Usability of 4-axis CNC Machining?
- Manufacturing Curved Surface Features: 4-axis CNC machining excels at creating curved and angled surfaces, specifically for angles about a single axis.
- Illicit Tolerance: This is best for applications that require a higher precision level compared to 3-axis machines and have fewer setups to improve accuracy.
- Machining Multi-sides: A 4-axis CNC is ideal for part features on multiple sides because it can rotate the part for easier access to those surfaces.
- High-volume Production: 4-axis CNC machines are efficient in high-volume production because they can machine complex parts that require fewer setups.
What is 5-axis CNC Machining?
A 5-axis CNC machine has more than just the standard left-to-right, front-to-back, and up-to-down movements. Other than the standard axis, it has two or more rotary axes (A, B, and C). With all of its various motions, the 5-axis is able to allow cutting at virtually any angle, making it possible to machine exotic and complex parts with many smooth surfaces, angles, and contours.
In addition, they can carry out ongoing milling that requires no time wasted, nor any additional manual process required, since the workpiece will automatically rotate for the user. 5-axis CNC machining tools are made up of three linear axes and two rotary axes. The three joining linear axes are:
- The X-Axis: Left and right movement of the work table horizontally
- The Y Axis: Up and down movement of the work table horizontally
- The Z Axis: Vertical movement of the cutting tools
In addition to these, the two rotary axes could be any combination of the following:
- The A Axis: Rotary movement around the X-Axis
- The B Axis: Rotary movement around the Y-Axis
- The C Axis: Rotary movement around the Z-Axis
Benefits of 5-axis CNC Machining
- Complex Geometries: 5-axis CNC machining offers parts with complex designs and geometries.
- Machinable Sides: It can machine up to five different sides of a workpiece in one setup, providing efficiency and decreased production times.
- High Speed: Fewer setups mean faster production speeds to save time.
- Precision: 5-axis CNC machining provides precision parts. Since you only have one setup, additional variances that happen from changing setups are eliminated.
Drawbacks of 5-axis CNC Machining
- Expense: 5-axis CNC Machines cost considerably more than 3-axis and 4-axis models, and typical continued costs of maintenance and operation, etc., should all be considered.
- Operator Training: Operating a 5-axis CNC machine is complicated, requiring specialized skills and training for operators.
- Programming: Programming for 5-axis machines is a more complicated process because there are two additional variables.
Usability of 5-axis CNC Machining?
- Complex Shapes: 5-axis CNC machines are ideal for parts that have complicated and intricate shapes that simple machines cannot make.
- High Volume: CNC machines are great for parts with high production volume since these machines can lower the cost of every part.
- Precision Parts: 5-axis CNC is necessary to make high-precision parts, particularly in industries like R&D, aerospace, and medical.
- Multi-Side Machining: If you have parts with features on multiple sides, the 5-axis CNC process is great since it allows machining every face of the part in one setup.
Factors to Consider While Choosing 3-axis, 4-axis, and 5-axis CNC Machining
It needs major considerations to choose the right CNC machining method for your manufacturing needs. Here are a few of them:
- Cost: In the product manufacturing process, the cost factor always comes first. 3-axis machining is your best option if your budget is tight. Consider a 4-axis or 5-axis CNC only if your budget allows for it.
- Application: Multi-axis machining (like 5-axis) is needed for applications that require ultra-high precision, like aerospace parts, medical devices, defence equipment, aircraft parts, and dental implants.
- Part Shape: Simple components can be made on 3-axis machining, which is cheaper. However, if the part is complex enough to run on 3-axis machining, it may be costly and result in scrap or defects. Therefore, a 4-axis or 5-axis machine is usually desired for complex shapes. The choice of 4-axis or 5-axis can vary depending on the geometry of the part.
- Machining Process: If you own a CNC machine, your paths may be a function of the machine type. For example, 3-axis movement is usually used in vertical milling machines, whereas a milling machine with a rotary table can act like a 4-axis machine. However, some CNC milling machines are configured with a 5th axis for machining.
- Production Volume: The number of axes you require depends on your level of production. 3-axis machining is suitable for low-volume machining. As you increase your production, multi-axis machining centres are the best option.
Conclusion
3, 4, and 5-axis CNC machines provides different features and have unique advantages, applications, and overall costs. Now that you have the above information, you can be better informed to figure out what machine will meet your needs for your next project. Additionally, Premium Parts offers a diverse range of product manufacturing services according to your needs. From CNC machining, 3D printing, and injection moulding, to laser cutting, and sheet metal fabrication, you can have our premium manufacturing solutions. We ensure quality and precision, no matter what level of production you require. So, take the first step with us by requesting a quote today!
FAQs
Q1: How many axes do you need to make the finished product more accurate?
The more axes you have, the better the accuracy of the finished product. Because multi-axis machines require fewer setups of the workpiece, the possibility for error and consistency issues is reduced, and ultimately, accuracy and precision.
Q2: How does the number of axes impact the range of materials that can be used?
The number of axes does affect the range of machinable materials. With additional axes, a machine can approach hard-to-machine materials from more angles. With the ability to approach materials from different angles, hard-to-machine materials are easier and more effectively machined, thus increasing the total range of machinable materials.
