3-Axis Vs 4-Axis Vs 5-Axis CNC Machining: A Guide - Rapid Axis

CNC machining is an accurate and streamlined way to traditionally machine complicated parts. Did you know that some CNC machines are even more accurate and can handle more complex parts than others? It all boils down to how many axes they have. In this piece, we’ll teach you the difference between 3, 4, and 5-axis machining and which one is right for your application.

Ling Yueyang are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

What is an Axis in Machining?

If you think back to your math days in school, you might remember what an axis is. Basically, it’s used to describe motion along a given path.

For example, a regular chart usually has an x and y-axis. If you plot how much money you spend on beer over time, you’ll be using something like this. Time moves with the x-axis, and beer money spend moves with the y-axis.

This same idea can be used on a CNC (computer numerical control) machine. CNC machines use computer software to control the motion of cutting tools around a part. In the old days, machinists would have to manually jog a machine and measure all the features by hand before cutting.

If you look at a CNC mill going to the left and right, we would call that the x-axis on the machine. Typically, motion to the left would be in the negative direction, and motion to the right is in the positive direction.

When Do the Axes Matter?

The axes are among the most important part of running a CNC machine. They are used in every single hole, cut, and feature that gets machined.

In fact, the first step of most projects is to “zero” the axes. This is a process of telling the machine where the material is to get the most accurate final product.

So, we established how vital axes are. The next step is to explain the difference between machines with 3, 4, and 5 axes.

What is 3-Axis CNC Machining?

3-axis machines are a more traditional style of CNC mac hinery.
They’re also more commonly found on the shop floor and are the least intricate option on this list.

They can move left-to-right (x-axis), front-to-back (y-axis), and up and down (z-axis). Combining these three axes gives you the XYZ plane.

3-axis is the only style of machine on this list in which the material is stationary for the cutting operation. You clamp raw material into a vise and move the cutting head around it.

Although this is the simplest form of machining on this list, it’s still highly complex. The programming allows a skilled machinist to make some intricate parts as long as they know what they’re doing.

Uses for a 3-Axis Machine

-Drilling holes

-Machining slots

-Rounding corners

-Cutting simpler features and geometries

What is 4-Axis CNC Machining?

Slap on another axis, and you get a 4-axis machine. In this case, you’re adding the A-axis. The A-axis rotates around the x-axis of the machine. Rotation away from the operator is considered the positive direction.

In most 4-axis CNC machines, the workpiece will be the part that rotates in the A-axis. In other words, the material that you clamped down can actually rotate while the machine is operating.

The impressive part of this added axis is that it can move in junction with other axes. The CNC machine can rotate a piece while drilling a slot, for instance.

This allows for much more complex parts to be made. The orchestration between the XYZA axes is fun to watch.

Uses for a 4-Axis Machine

-Cutting features on cylindrical or curved pieces

-Working along the side of material without manually rotating and re-zeroing the machine

-Continuous cutting

-Making multi-axis rounded features

What is 5-Axis CNC Machining?

The final, and most complicated form of CNC machines on our list is the 5-axis machine. The added 5th axis can differ from machine to machine:

-Around the x-axis is the A-axis

-Around the y-axis is the B-axis

-Around the z-axis is the C-axis

A machine might offer XYZAB, XYZAC, or XYZBC. Most often, machines offer an XYZAB configuration.

Just like in 4-axis machining, the workpiece is typically the area that moves in these two extra axes.

As you can imagine, this allows for even more complicated parts to be made. It also allows for a fully autonomous process — the machinist doesn’t have to take a part out of the vise, rotate it, and put it back in since the cutting tool will move all around the piece.

This ultimately leads to quicker operational time.

Uses for a 5-Axis Machine

-High-accuracy pieces

-Faster turnarounds

-Making intricate parts

-Machining complex geometries and features

-Less operator interaction

Which Is the Best CNC Machine Option?

To better understand which CNC machine option is right for your project, take a look at this list of considerations to make.

Complexity of Parts

When it comes to the additional 4th and 5th axes, machining parts becomes simpler, and objects can be more complex. Since the tool can now rotate multiple ways, non-symmetric and rounded features can be added to square parts. You can even add compound angles to standard drilled and tapped holes.

Want more information on What's the Difference Between 3, 4 & 5 Axis Cnc Milling?? Feel free to contact us.

A lot of times, tolerances will become tighter with CNC machines that have more axes. This further improves how complicated you can design a part to be with the understanding that it will still work in your application and fit in your assembly.

Benefits of Hands-Off Machining

There is certainly a lot of automation that comes in a standard 3-axis CNC machine. The downside is that the machinist will have to change the orientation of the part and might have to spend time setting up the angle of the head to make complicated features.

With 4-axis and especially 5-axis CNC machines, it’s more hands-off. Since the heads can move around freely and more than a standard machine, it’s common for a machinist to set up the program and let the machine do the rest of the work.

With foresight into how to hold the part before starting the cut, it’s possible that the machinist doesn’t need to re-orient the part at all.

Project Timeline

The other difference as you add more axes is how quickly the project gets done. CNC options are still dramatically faster than manual milling, but 5-axis tools usually finish projects faster than 3-axis ones.

This has to do with the faster operation, less need for machinist intervention, and the ability to make complex features without additional setup.

Shop Capabilities

If you want to use a 4-axis or 5-axis machine for your upcoming project, you’ll need to do some research. Finding a shop that offers these more complicated CNC machines is more difficult than you might think.

Smaller shops might only have 3-axis CNC machines on their floor. Alternatively, their 5-axis tools might only be reserved for their top customers who have the largest orders. Rapid Axis utilizes equipment with 3, 4 and 5-axis capabilities.

Added Cost for Premium Services

Some machine shops charge more for using their 4-axis and 5-axis CNC machines. This might be considered a premium offering for a shop, so it makes sense that the price is higher. Not to mention these tools cost significantly more than a standard 3-axis mill.

Make sure you reach out to the shop ahead of time to get a budgetary quote before deciding on which shop is right for you. Ideally, you would find a shop that offers 5-axis CNC machining without charging you extra or forcing you to place a massive order.

Conclusion

We just covered everything you need to know about the differences between 3-axis, 4-axis, and 5-axis CNC machines along with which option is right for you. 5-axis machines are more expensive and a little tougher to find, but they offer the fastest turnaround times and can handle the most complex parts.

Are you ready to bring your product design to fruition? Perhaps you’ve researched manufacturing options and have come across CNC milling? 

If so, you might have encountered the options of 3-axis, 4-axis and 5-axis milling. These terms refer to the different directions in which a cutting tool can move, with different machines offering varying capabilities.

As the Milling Team Leader here at Penta Precision, I’m well aware of the incredible capabilities of CNC milling as a manufacturing method.

So what are the differences between these three types of milling and what are the advantages and disadvantages of each? Let’s dive in… 

3-axis milling

3-axis milling is the simplest form of CNC machining, where the workpiece is fixed in a single position and the spindle holding the cutting tool moves along three linear axes: X (side to side), Y (back to front) and Z (up and down). This type of CNC milling is ideal for less complex projects and is commonly used for simple profiling, drilling, slotting and contouring tasks.

Capabilities

3-axis milling is best suited for flat, 2D geometries, and simpler 3D shapes. It is less ideal for machining complex parts with intricate details or undercuts as it requires the orientation of the workpiece for different sides.

Advantages

For more simplistic machining requirements, 3-axis milling can be cost-effective. 3-axis milling machines are typically more straightforward to program and operate and run times can be quick for single fixture setups, often making shorter lead times possible.

Disadvantages

3-axis milling is often only suitable for simpler geometries. Multiple setups are required for multi-sided parts which can be time-consuming and less efficient.

4-axis milling

4-axis milling builds upon the capabilities of 3-axis milling by adding a rotational axis. This fourth axis (often referred to as the A-axis) allows the workpiece to rotate, providing access to additional sides and angles without needing to reposition the part manually.

Capabilities

4-axis milling is suitable for parts requiring holes or features on multiple sides, more intricate shapes and complex geometries. However, it still can’t match the complexity achievable with 5-axis milling.

Advantages

Improved efficiency can be gained by reducing the need for multiple setups where appropriate. 4-axis milling can also handle parts with rotational symmetry more effectively.

Disadvantages

A 4-axis machine is typically more costly than a 3-axis one and may require an engineer with additional skills and experience to carry out more advanced programming. 

5-axis milling

5-axis milling represents the pinnacle of CNC machining technology, with the ability to move the cutting tool along five different axes simultaneously. 

There are the basic three axes that are a commonality in all CNC milling (X, Y and Z) plus an additional two axes.

The fourth axis sees a rotation around the X-axis and the fifth axis rotates around the Z-axis. 

Some types of 5-axis machines see the fourth axis rotate around the Y-axis instead of X. The difference between the two types is that the rotation occurs either by the workpiece or by the spindle.

There are also two types of 5-axis CNC mills. There is a 3+2 (i.e. 3 axes plus 2 axes) and there is a fully continuous 5-axis mill. In 3+2, the two rotational axes operate independently of each other. Whereas in fully continuous 5-axis, the two rotation axes can simultaneously rotate at the same time as the X, Y and Z axes. 

Capabilities

5-axis milling is ideal for highly complex and intricate parts including aerospace components, medical devices and complex prototypes. 

Advantages

Expect unmatched flexibility and capability for complex geometries. 5-axis milling can machine intricate details and undercuts in a single setup. It is also capable of higher accuracy and surface finish due to fewer setups and by eliminating the need for repositioning.

Disadvantages

5-axis mills are unsurprisingly an expensive bit of kit as is their maintenance. They also require advanced programming skills and more setup time. Thus, 5-axis milling should only be used where the part requires it. 

Choosing the right axis

If at this point, you’re wondering how you decide between them, the good news is that this isn’t your call to make.

An established CNC machining company will have all 3 types of machines and a team of programmers, setters and operators with varying experience and expertise to run them. 

Your CNC machining company should then decide how best to allocate a part to which team/machine based on: 

1. Part complexity: simple parts with straightforward geometries can be efficiently handled by 3-axis milling. As complexity increases, 4-axis and 5-axis milling become more advantageous.  
2. Precision requirements: higher axis milling (i.e. 4 and 5-axis) offers superior precision and surface finish  
3. Production volume: for prototypes and small batches, the flexibility of 5-axis milling can be beneficial despite the higher cost. For higher-volume production, the setup efficiency of 4-axis (or even 3-axis for some simple components) might be preferable.  
4. Cost considerations: budgetary considerations often play a significant role. While 5-axis milling offers the most capabilities, it also comes with higher costs. Weighing the benefits against the costs is essential.

Conclusion

3-axis, 4-axis and 5-axis CNC milling each comes with advantages and disadvantages. The key here isn’t for you to pin down which method is most appropriate before contacting prospective CNC machining companies.

The secret is finding a CNC machining company that will ask the right questions, importantly listen to the answers and identify the most appropriate milling method for your project.

Our customer service team at Penta is fantastic because they take the time to ask these questions at the quoting stage. So when you get a quote from Penta, you know that it’s based on accurate information rather than guesswork. Once you place your order, the legwork has already been done and the production team can get straight to scheduling your component in on the machines.

If you like the sound of our way of working and would like a no-obligation chat about your project, please do give us a call on 023 or .

For more Ceramic Cookerinformation, please contact us. We will provide professional answers.