A 3D milling machine, also known as a CNC machining center, uses computer control to create complex parts from raw materials. These machines can perform advanced functions such as surface profiling and drilling with exceptional precision. This makes them an indispensable tool in manufacturing. They are capable of creating prototypes and reconstructing specific parts of objects on a large scale. In this article, we will learn the basics of 3D milling, which are essential for CNC operators to understand.
What is 3D CNC milling?
Usually, a CNC machine needs 3 axes to accurately reproduce an object. However, recent changes in software and machines mean that 2-axis (2D) or even 1-axis (1D) machines can be effective CNC mills. In this guide, we will look at three types of 3D mills. CNC milling is a subtractive process that removes material from a block to create an object. Subtractive manufacturing is cutting out of a solid piece of material. Essentially, it is a three-dimensional sculpture. Mechanics use a computer program called CAM (Computer Aided Manufacturing). CAM communicates with the CNC machine where to mill and to what depth. Generally speaking, 2-axis and 1-axis machines can only mill in 2D or 1D. Whereas 3-axis machines can mill in all three dimensions. They are generally more expensive than their 2- and 1-axis counterparts. In addition, most CNC machines are computerized. If you want to use a manual machine, you need to find one that can be converted to CNC technology. However, very few people can do this.
How does 3D compare to traditional machining?
3D milling machines offer many advantages compared to traditional machining methods, making them ideal for certain applications. They are particularly good at creating complex objects that other machines cannot make in any other way. The machine is also useful when the user needs to quickly and accurately make many copies of an object. These machines operate using powerful rotating heads, which can be matched to a range of attachments and cutting tools. They move in three dimensions using the X, Y, and Z axes, allowing for the creation of any objects at any angle. CNC milling machines use computer-controlled tools to cut various materials.
3D Milling vs Laser Cutting Machine
3D milling machines operate differently than laser cutters, which in turn means that they have different capabilities. Here are 5 differences between 3D milling and laser cutting.
- Diameter – A laser cutter has a small diameter, which means it can only cut smaller parts than those created with a 3D mill.
- Speed – Laser cutters are slower than 3D milling machines. A laser cutter can only handle one material at a time, while a mill can handle multiple materials simultaneously. Production costs with laser cutting are higher than with 3D milling.
- Durability – Laser cutting machines will require repair or replacement after 5 years, unlike CNC mills, which can operate for decades.
- Dependencies – The accuracy of laser cutter positioning is limited by its software, while a CNC milling machine depends only on its own accuracy and precision.
- Number of axes – Laser cutters use only one axis for cutting, whereas CNC milling machines have many, allowing for deeper cuts.
Advantages of 3D milling
3D milling machines offer a range of advantages compared to traditional 2D milling. These include:
- Improved surface finish
- Larger work envelope
- More accurate form
- It is faster than CNC machining, while offering better accuracy than 2D drilling.
The 3D milling process involves moving the mill through its material, simultaneously rotating in the directions of the X, Y, and Z axes. This allows for the cutting of complex geometries from larger bulk material.
3-axis CNC milling machines, 3D milling
Three-axis CNC milling machines are used to create three-dimensional objects from metal, plastic, or other materials. They are computer-controlled and can be used to create a wide range of objects, including precision parts and medical implants. A 3-axis CNC milling machine operates on the same principle as a 2-axis milling machine, but includes an additional linear movement and can be used with other tools, such as laser engravers, polishers, etc. Three-axis milling machines consist of two independent rotary axes and one linear axis. A mechanical or electrical connection connects the three axes and allows the cutting tool to rotate along each axis. A 3-axis milling machine has 3 main movements:
- Moving along the Z axis perpendicular to the cutting tool, adjusting the feed of the Z axis to cut along the surface of the workpiece.
- Movement along the X axis parallel to the cutting tool allows the milling head to move along and through the workpiece.
- Movement along the Y axis, perpendicular to the cutting tool, allows the milling head to move from one end to the other over the workpiece.
Types of 3-axis CNC milling machines
Three-axis CNC milling machines are divided into three types:
- Horizontal mill - A horizontal three-axis CNC milling machine is a machine that can move the tool in three directions: left and right, front and back, and up and down. This type of mill is used for machining parts that are too large or heavy to be machined on a vertical 3-axis CNC milling machine.
- Vertical mill - A vertical 3-axis CNC milling machine is a machine that uses three linear axes to move the tool or workpiece in space. These three axes are often referred to as the X, Y, and Z axes. The X-axis moves the tool or workpiece horizontally, the Y-axis moves vertically, and the Z-axis approaches or moves away from the spindle.
- Bridge mill - Bridge-type 3-axis CNC mills are similar to standard 3-axis CNC mills, but they have an additional bridge that encompasses the workpiece, allowing the tool to reach all sides of the workpiece. This increases the machine's flexibility, enabling it to handle larger or more complex parts. They are often used for generating patterns from large surfaces or for machining small details.
3-axis mill specifications
The specifications of three-axis milling machines vary depending on the model, but some typical specifications include the power of the milling machine, speed, and tool size:
- Power - is usually measured in horsepower or the amount of energy that an engine can produce. The power of a milling machine is related to the cutting speed. It is also important to consider the area of the mill that needs to be powered to see what the actual power is. The larger the engine, the more powerful it will be, and you can run it at higher speeds without worrying about burning or damaging the engine. This also ensures the efficiency of the machine.
Price comparison of 3-axis CNC machines
When comparing the prices of 3-axis CNC machines, several factors need to be taken into account. The first one is the size of the machine. Some machines are larger and can handle bigger items, while others, smaller ones, can only handle smaller items. The second factor is the quality of the machine. Some machines are made from higher quality materials and have more features, while others are made from cheaper materials and thus have fewer features. The third factor is the brand of the machine. Some machine brands are known for higher quality, while others are quite the opposite. You might be willing to pay more to get a good quality machine. The last factor is the machine's capabilities. The larger the capacity of the machine, the more equipment and software it has, which affects the price. As mentioned above, the price range of a 3-axis CNC machine can vary depending on the specific brand and model of the machine and the features and functions it offers. However, generally, the price of a three-axis CNC machine ranges from several thousand to tens of thousands of zlotys.
Application of 3-axis CNC machining
Three-axis CNC machining is used in various industries, including the aviation, automotive, medical, and manufacturing industries:
- aviation industry - 3-axis CNC machining is used for the design and production of aircraft components, such as air conditioners, air valves, and other critical components.
- automotive industry - 3-axis CNC machining is used to produce a wide range of parts for cars and other vehicles. Some parts that can be processed using a 3-axis CNC machine include engine blocks, brake discs, and gearbox housings.
- field of medicine - In the medical industry, 3-axis CNC machining is commonly used for the production of medical devices and implants. Some of the most popular medical devices manufactured using it include pacemakers, limb prosthetics, and joint prosthetics. Thanks to the use of this type of CNC machining, medical device manufacturers are able to create complex shapes and components that are precise and durable.
How to start using a 3-axis CNC machine?
There are a few things you need to know before using a 3-axis CNC machine.
- First, you need to understand the machine's coordinate system. X refers to the tool's left and right direction, Y refers to the tool's forward and backward movement, and Z refers to the tool's upward and downward movement.
- Secondly, you need to know the machine's programming language. There are 2 basic types of programming languages used in CNC machines. One of the programming languages is CAM, and the other is G-code. CAM is easier to learn than G-code and allows you to start working quickly, but you may have limited types of devices that you can use to program with it. G-code is harder to learn, but it is used on almost every CNC machine. When learning to operate a CNC router, focus on one programming language and stick with it until you master the basic operations.
- Thirdly, you need to understand the characteristics of the machine. These are spindle speed, feed rate, acceleration, and backlash. Spindle speed refers to the revolutions per minute. Feed rate refers to the movement occurring in millimeters per second. Acceleration refers to the change in tool displacement when the tool accelerates.
- In the end, you need to understand tool changing and tool cracking. They refer to how quickly a tool changes direction during movement or whether the tool cracks, that is, it jams in the spindle. This speed is sometimes called tool change time. These times are marked on the machine, but they vary depending on the machine and the programming style used.
How to Choose the Right 3-Axis CNC Milling Machine
When choosing a 3-axis CNC milling machine, several factors need to be considered. The most important of them is the size of the object being machined, which the machine can accommodate. Other factors to consider include the speed and precision of the machine, and the types of materials it can cut. Small machines are used for cutting thin strips or small parts. They are used for projects such as engraving, drilling, and milling. They are cheaper, but not as accurate. For larger projects, larger 3-axis milling machines are available. Their feed rate is usually 4-20 inches per minute. They are used for turning, milling, drilling, and cutting. They are more expensive than smaller machines. The accuracy of a three-axis CNC milling machine depends on the spindle diameter and feed rate. The feed rate determines the precision of milling. The higher the feed rate, the more accurate the cut. A smaller spindle diameter makes the machine less accurate.
Summary
A 3-axis CNC milling machine is a powerful tool that can be used for various projects. When choosing a milling machine, it's important to consider the size and power of the machine, as well as the features that are important to you. The best milling machine for your needs will depend on your specific projects and requirements. Our company provides the best CNC milling services, which will certainly improve the quality of your product.