CNC machining is an important technique known for its speed, precision, and efficiency. Short for Computer Numerical Control, it uses advanced machines to ensure accuracy. However, when you dive into this term, you often come across a debate over 3-axis VS 5-axis CNC machining.
These two types of CNC machining often feel confusing and sound similar. However, they vary in several aspects, from accuracy to quality of products. So, how would you decide which one is suitable for your project? Worry not! This article will explain the differences between these two processes. This will help you know which CNC process is best for you.
Basic Rundown of 3-Axis & 5-Axis Machining
CNC machining is a cutting, shaping, and manufacturing process. The popularity of CNC machining is due to its versatility. This process can be performed in two ways, leading to its type. Before we explain their differences, let’s first understand 3-axis and 5-axis machining.
3-axis machining is when cutting tools move only in three axes (X, Y, Z). In simple words, these cutting tools can rotate left/right, up/down, and front/back. However, in 5-axis CNC machining, cutting tools move in five axes. The two additional axes allow the tool to rotate in extra directions, making complex parts.
Both of these types work using CNC machines. Actually, these machines are computer-controlled. Engineers first prepare a design using CAD software. After preparing the model design, the CAM software translates the instructions into G-code. These instructions are then given to the cutting machines. Those machines follow them and cut the material precisely.
However, in 3-axis machining, cutting tools only move in the three axes. The workpiece stays stationary, and the cutting tool rotates around it in three directions to cut it. As a result, you can attain basic shapes such as holes and flat surfaces. Therefore, a 3-axis machine is a cost-effective and straightforward machining process.
On the flip side, in 5-axis machining, cutting tools can move in 5-axis. Five axes mean five different directions. The three axes are regular X, Y, and Z. However, it includes two additional axes. These axes help the tools move in almost all directions around the workpiece. As a result, you can get intricate and complex geometry parts like deep cavities and curved surfaces.
3-Axis VS 5-Axis CNC Machining: Key Differences
I hope the above section has given you enough understanding of the basics of CNC machining. Right? Now, let’s dive in and explore what really sets the 5-axis and 3-axis apart.
1- Number of Movement Axes
In CNC machining, axes refer to the directions in which cutting tools move to cut the workpiece. This is one of the most prominent differences between 5-axis and 3-axis machining. For example, in 3-axis machining, cutting tools move in three axes: X, Y, and Z. Along the x-axis, cutting tools move left to right. The y-axis is responsible for the front and back movement of tools.
However, the last z-axis moves the machine up and down. On the flip side, 5-axis machining has five axes for cutting tool movement. Three are regular X, Y, and Z. The additional axes involve the A and B axes. A-axis provides rotation around the X-axis. At the same time, the B-axis provides rotation around the Y-axis. These additional rotational axes make this type more advanced.
3- Tool Orientation and Access
This point tells us how cutting tools are oriented and how easily they can reach the material’s surface. In 3-axis machining, the cutting tool always stays in a fixed position. It can move only up/down, back/forth, and left/right. This means the tool can only reach the surface directly underneath it. If you need to cut sides, you have to reposition the part.
On the reverse side, cutting tools do not remain stationary. Moreover, they also do not move only in three traditional directions. The two additional axes help the tool move and rotate at all angles. It can tilt to the sides, rotate around the part, and cut every side of the workpiece. So, tool orientation and access to any side are far easier in this process.
3- Complexity of Parts
Another distinction between 3-axis and 5-axis machining is the type of part they can create. Let’s begin with the 3-axis machining process. As you can see, cutting tools move only in three axes in this process. This limitation in movement makes it difficult for the tools to reach different sides of the workpiece. As a result, you can only create basic shapes of simple geometry.
On the other hand, the 5-axis machining process uses more advanced tools. They use two additional axes, A and B. Those rotational axes help the cutting tools reach any side of the part. As a result, you can attain complex, multi-side, and 3D parts. Moreover, you can also create parts with deep pockets, angles, holes, and contours.
4- Setup Requirements
Setup requirements involve how you prepare the machine and workpiece for machining. Both 3-axis and 5-axis machines offer different setup requirements. For example, 3-axis CNC machining can be more demanding and time-consuming. WHY? As I said above, in the 3-axis, CNC machines can move only in three directions. So they can reach a certain surface from one angle.
That means creating features like holes or cuts becomes difficult. You must stop the machines, reposition the material, and start again. Conversely, 5-axis machines are more advanced. Cutting tools can tilt and rotate all around the workpiece. You don’t have to reset the entire machine for complex features. In one pass, you can create all geometry shapes.
5- Surface Finish Quality
Another key difference that sets 5-axis and 3-axis machining apart is the finish quality of products. When discussing 3-axis machining, cutting tools approach the material only from the top. Therefore, the surface of the workpiece is cut in a step-by-step pattern. Moreover, the cutting tools cannot tilt and use small movements to carve out curves.
These small movements create tool marks on the surface of the material. So, the final products don’t have a quality finish. On the other hand, 5-axis machines are highly effective. They can move in various directions and create the shape in one pass. Hence, there are no tool marks left on the workpiece. So, final products have more smoother and even surfaces that don’t need finishing.
6- Precision and Accuracy
Regarding CNC machining, two factors, accuracy and precision, matter a lot. Both types of CNC machining offer different levels of precision. For example, cutting tools move in three directions in 3-axis machining operations like CNC milling. You must remove the workpiece and reset the whole machinery for detailed parts. This reclamping can cause misalignment.
Due to misalignment, the final part can be slightly compromised with accuracy. On the flip side, 5-axis machining is highly accurate. You don’t have to reposition the workpiece for complex shapes. The cutting tools can reach all angles of the part without stopping. This reduces the chances of misalignment and ensures accuracy in the final product.
7- Speed and Efficiency
In manufacturing, speed, and efficiency are significant factors. They decide how quickly you can create a large number of parts in less time. In this regard, both 3-axis and 5-axis machining varies. For instance, a 3-axis machine is a slower process comparatively. WHY? The first reason lies in the movement of cutting tools in limited directions. They move only in three directions.
For detailed shapes, you have to stop and reposition the workpiece. All this takes time, which makes this process slower. On the other hand, 5-axis machining is high-speed. The machines can move in several directions. You don’t have to reposition them and create the shape in one pass. This reduces the time consumption and makes this process more efficient.
8- Application Range
Due to contrast in several aspects, the usability of both machining processes also varies. Both of them offer a range of applications but in different industries. Let’s first look at the typical applications of 3-axis CNC machining. It is used for:
- Flat surface milling and basic shaping
- Drilling, slotting, and contouring on simple parts
- Machining of brackets, plates, and basic enclosures
- Ideal for woodworking, metal fabrication, and prototyping
- Used in small workshops and general manufacturing
On the reverse side, 5-axis machining common uses involve:
- Complex 3D parts with curved or angled surfaces using CNC turning
- Deep cavity cutting and multi-side machining
- Manufacturing of turbine blades and impellers
- Ideal for aerospace, medical, automotive, and defense industries
- Used for high-precision molds, surgical tools, and engine parts
9- Material Waste
Material waste is the amount of material cut away and discarded during machining. Understanding this difference is crucial to saving overall machining costs. If we begin with 3-axis machining, the cutting tools move in three directions only. So, you have to reposition the workpiece each time for a definite shape. This repositioning can lead to overcutting, mistakes, and poor alignment.
As a result, excessive material wastes in the form of chips. On the contrary, 5-axis machining is far more efficient when it comes to using material wisely. As you know, cutting tools can move in all directions. The problem of repositioning is no more here. So, the machine cuts only where needed. As a result, material removal and leftovers are minimized in this process.
10- Machine and Operation Cost
Last but not least, one most important factor to consider between both types is their cost. Let me differentiate both based on prices. As I said above, 3-axis machining is a simple process. You can create simple parts, and it does not require complex tooling. Moreover, using those tools is straightforward. You don’t have to invest in skillful staff, reducing labor costs.
So, a 3-axis CNC is ideal if you are on a tight budget. On the other hand, 5-axis machining is a complex process. It has advanced machinery built with advanced technology. Those machines come at higher prices, which increases its initial cost. Moreover, to operate 5-axis machines, you have to hire expert staff. This can further increase labor costs.
Quick Highlight: 5-axis machining is an expensive process initially. However, the advantage of 5-axis machining compensates for its higher prices. For example, you can get highly accurate and precise parts quickly. Besides, less material waste, reduced replacement, and low maintenance make it cost-friendly in the long run.
Frequently Asked Questions
Which is better: 3-axis or 5-axis machining?
It depends on your project’s needs. If you need simple parts on a low budget, 3-axis machining is ideal. However, for complex geometry products, you should choose 5-axis machining.
Can 3-axis machines make complex parts?
3-axis machines can make complex parts to a certain extent. You must constantly reposition the workpiece and cutting tools for the complex part. This can affect the accuracy and precision of the final products.
Is the 5-axis suitable for small businesses?
The 5-axis is suitable for small businesses only if they need complex parts. If you run a small business with simple parts, the 5-axis is unstable. For this purpose, you should choose 3-axis machining. It will save you time and money.
Can I upgrade from 3-axis to 5-axis?
No, you cannot directly upgrade the 3-axis to the 5-axis. The reason is that machines are built differently from the beginning in both types. For example, 5-axis machines use extra motors, axes, and control systems. These things are absent in the 3-axis and cannot be added later.
Conclusion
Let’s conclude that both 3-axis and 5-axis machining play vital roles in manufacturing. Understanding how each type works and what makes it unique can help you make a confident decision. In this article, I have explored several differences that set them apart. However, choosing between 3-axis and 5-axis machining depends on the needs of your project.
Both of these CNC machining types offer unique features. If you are working with basic shapes, flat surfaces, and a tight budget, the 3-axis should be your go-to option. However, the 5-axis is a slightly complex procedure. It uses advanced technology to cut and shape materials. So, if your project involves complex geometry parts, it is a perfect fit for you.