A 3D milling machine, also known as a CNC machining center, uses computer control to create intricate parts from raw materials. These machines can perform advanced functions such as surface profiling and drill with extreme precision. This makes them an indispensable tool in manufacturing. They can create prototypes and reconstruct specific parts of large-scale objects. In this article, we will learn the basics of 3D milling, which are essential for CNC operators to understand.
What is 3D CNC milling?
Typically, a CNC mill needs three axes to reproduce an object accurately. However, recent developments in software and machines mean that machines with two axes (2D) or even 1 axis (1D) can be effective CNC milling machines. This guide will look at three types of 3D milling machines. CNC milling is a subtractive process that removes material from a block to create an object. Subtractive manufacturing is the cutting of a fixed 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. In general, 2-axis and 1-axis machines can only mill in 2D or 1D.
In contrast, 3-axis machines can mill in all three dimensions. They are generally more expensive than their 2-axis 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, only a few people can do this.
How does 3D compare to traditional machining?
3D milling machines offer many advantages over traditional machining methods, making them ideal for specific applications. They are especially good at creating complex objects that other machines can’t do any other way. The machine is also functional when the user needs to make multiple copies of an object quickly and with high precision. The machines operate using powerful rotary heads that can be matched with various attachments and cutting tools. They move in three dimensions using the X, Y, and Z axes, allowing them to create any object at any angle. CNC milling machines use computer-controlled tools to cut a variety of materials.
3D milling vs. laser cutting machine
3D milling machines work differently from laser cutting machines, which means 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 cutter.
- Speed – Laser cutters are slower than 3D milling machines. A laser cutter can only handle one material at a time, while a milling machine can handle multiple materials at once. Production costs with laser cutting are higher than with 3D milling.
- Durability – Laser cutting machines will need to be repaired or replaced after 5 years, unlike CNC milling machines, which can run for decades.
- Dependability – The positioning accuracy of a laser cutter is limited by its software, while a CNC milling machine only depends on its accuracy and precision.
- Number of axes – Laser cutters use only one axis for cutting, while CNC milling machines have multiple axes, allowing for deeper cuts.
Advantages of 3D milling
3D milling machines offer a number of advantages over traditional 2D milling. These include:
- Increased surface finish
- A larger envelope to work with
- A more accurate mold
- It is faster than CNC machining while offering better accuracy than 2D drilling.
The 3D milling process involves moving the cutter through its material while rotating in the X, Y and Z axis directions. This allows complex geometries to be cut out of more considerable bulk material.
3-axis CNC milling machines
Three-axis CNC milling machines create three-dimensional objects from metal, plastic, or other materials. They are computer-controlled and can create a wide range of objects, including precision parts and medical implants. A 3-axis CNC milling machine works on the same principle as a 2-axis milling machine, but includes other linear motion 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 links 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 Z-axis feed 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.
- The direction 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
CNC triaxial milling machines are divided into three types:
- Horizontal milling machines – A horizontal machining centers have machine that can move the tool in three directions: left and right, front and back, and up and down. This type of milling machine is used for parts that are too large or heavy to be machined on a vertical milling machine.
- Vertical mill – A vertical 3-axis CNC milling machine is a machine that uses three linear axes to move a tool or workpiece through 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 away from the spindle.
- Bridge mill – Bridge 3-axis CNC milling machines are similar to standard 3-axis CNC milling machines, but have an additional bridge that covers the workpiece, allowing the tool to reach all sides of the workpiece. This increases the flexibility of the machine, allowing it to handle larger or more complex parts. They are often used to generate patterns from large surfaces or to small machine parts.
3-axis milling machine specifications
Specifications of three-axis milling machines vary from model to model, but some common specifications include milling machine power, speed and tool size:
- Power – is usually measured in horsepower, or the amount of energy the motor can produce. The power of the milling machine is related to the cutting speed. It is also important to consider the area of the mill to be powered to see the actual power. The larger the motor, the more powerful it will be and you can run it at higher speeds without worrying about burning or damaging the motor. This also ensures the efficiency of the machine.
- Speed – refers to the speed at which the workpiece moves during machining and is often measured in revolutions per minute. Speed determines how much material is removed with each pass and can also be expressed in feet of surface area per minute (sfpm). When the diameter of the workpiece exceeds eight inches, reduce the speed to prevent overloading the spindle motor.
- Dimensions – the tools of a three-axis CNC milling machine are measured in millimeters. In general, the lower the number, the larger the cutter. For example, a 3mm tool is used for finishing operations, and a 45mm tool is used for heavy machining. Some CNC milling machines are equipped with multiple tools.
Price comparison of 3-axis CNC machines
There are several factors to consider when comparing the prices of 3-axis CNC machines. The first is the size of the machine. Some machines are larger and can handle larger workpieces, while other, smaller machines can only handle smaller workpieces. The second factor is the quality of the machine. Some machines are made of higher quality materials and have more functions, while others are made of cheaper materials, thus having fewer functions. The third factor is the brand of the machine. Some manufacturers of machines are known for their higher quality, while others are the opposite. You may be willing to pay more to get a good quality machine. The last factor is the capacity of the machine. The higher the machine’s capacity, the more hardware and software it has, which affects the price. As mentioned above, the price range of a three-axis CNC machine can vary depending on its specific make and model and the features and functions it offers. However, in general, the price of a 3-axis CNC machine tool ranges from a dozen to tens of thousands of zlotys.
Application of 3-axis CNC machining
Three-axis CNC machining is used in various industries, including aerospace, automotive, medical, and manufacturing:
- aerospace industry – 3-axis CNC machining is used to design and manufacture 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 of the parts that can be machined with a 3-axis CNC machine include engine blocks, brake discs, and transmission housings.
- Medical field – In the medical industry, 3-axis CNC machining is commonly used to manufacture medical devices and implants. Some of the most popular medical devices manufactured using it include pacemakers, prosthetic limbs, and joint replacements. By using this type of CNC machining, medical device manufacturers are able to create complex shapes and components that are precise and durable.
How do you get started using a 3-axis CNC machine?
You need to know a few things before using a 3-axis CNC machine.
First, you need to understand the machine’s coordinate system. X refers to the left and right direction of the tool, Y refers to the forward and backward movement of the tool, and Z refers to the up and down movement of the tool.
Second, you need to know the programming language of the machine. There are 2 basic types of programming languages used in CNC machine tools. One programming language is CAM, and the other is G-code. CAM is easier to learn than G-code and allows you to get started quickly, but you may be limited in the types of machines you can use to program with it. G-code is more difficult to learn, but 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 it for basic operations.
Third, you need to understand the characteristics of the machine. These include spindle speed, feed rate, acceleration, and backlash. Spindle speed refers to revolutions per minute. Feed rate refers to the movement occurring in millimeters per second. Acceleration refers to the change in tool displacement as the tool accelerates.
Finally, you need to understand tool change and tool breakage. These refer to how quickly the tool changes direction during movement or if the tool breaks, i.e. jams in the spindle. This speed is called the tool change time. These times are stamped on the machine but 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, there are several factors to consider. The most important of these is the size of the workpiece the machine can accommodate. Other factors to consider are 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 diameter of the spindle and the 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 a variety of projects. When choosing a milling machine, it is essential 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 that will improve your product’s quality.