Computer numerical control (CNC) machining is a subtractive manufacturing process that enables manufacturers to accurately and economically create high-precision parts. CNC machining uses cutting tools to remove excess raw material from workpieces to create precise finished products from materials such as plastics, metals and composites. Today, product assemblies have many multi-axis machining options, from 3-axis to 5-axis and even 9-axis. In contrast, this article will focus on what 5-axis machining is and is it practical for large-volume parts? Does it result in higher cutting speeds? We will answer these questions and many more below!
5-axis machining – operation
A 5-axis machine is based on a tool moving in five different directions: X, Y and Z, and A and B, around which the tool rotates (these are rotary axes). Using a 5-axis CNC machine allows the operator to approach parts from all directions in a single operation, eliminating the need to reposition the workpiece between operations manually. 5-axis CNC machining saves time and is ideal for producing complex precision parts, such as those found in the medical, oil, gas, and aerospace industries.
5-axis machines
There are several different types of 5-axis machines that product teams should be familiar with, including indexable 5-axis CNC machines, continuous 5-axis CNC machines and CNC turning centers. Like 3-axis CNC milling, the tool moves only along three rotational axes and is not in constant contact with the workpiece, as in indexed 5-axis CNC machining. However, the machining rotary table and tool head can automatically rotate in both directions between operations. Indexed 5-axis machining is ideal for manufacturing housings, mounting jigs, and fixtures. It sits between 3-axis CNC milling and continuous 5-axis CNC machining regarding speed, accuracy, and ability to handle complex geometries.
In continuous 5-axis CNC machining, the tool and workpiece can rotate and move simultaneously during the operation, saving time and allowing operators to produce complex geometries with organic surfaces. Continuous 5-axis CNC machining provides better surface finish, speed, and dimensional stability but at the highest unit cost. CNC turning centers are virtually the same as CNC lathes, with one exception – they are equipped with CNC milling tooling. The workpiece is attached to a spindle that can rotate or remain stationary while the cutting tool removes material from the workpiece. Combining CNC lathe components with milling machines, CNC milling and turning centers provide a high level of precision and geometric versatility, making them ideal for producing loose rotary-symmetrical parts such as camshafts and centrifugal compressors. Such 5-axis CNC milling machines offer greater precision when machining deeper parts, hardened materials, higher productivity, and higher machining speeds. However, 5-axis machining is more expensive due to the need for specialized equipment and skilled labor.
Machining 3-axis vs. having 5-axis
The main difference between three-axis and five-axis milling machines is that the workpiece can be machined from three axes of the first axis and five axes of the second axis. Both are highly versatile, automated and repeatable manufacturing processes that enable fast and economical production of precision components. However, you may use one instead of the other for various reasons.
If you have a limited budget or need a cutting plane, a 3-axis machine may be your best choice. In addition to being less expensive than 5-axis machines, 3-axis machines are simpler to program, saving you the cost of working with expensive programmers and operators. In addition, setup time is shorter with 3-axis machining. If you need to produce deeper parts or parts with complex geometries, using 5-axis machining will be helpful. With a 5-axis machine, parts can be machined from all directions – without manual turning. With 5-axis machining, you’ll get higher productivity, greater precision, more freedom of movement, and the ability to produce larger parts faster.
How does a 5-axis CNC machine work?
Like any other CNC machine, a 5-axis CNC machine relies on computer instructions to control the movement of the cutting tool (and workpiece) to produce the desired part. The 5-axis CNC machining process begins with the designer creating a 3D model (computer-aided design) of the desired part using CAD tools. The machinists then export this CAD model to CAM (computer-aided manufacturing) software, which converts the drawing into a computer program (also known as G-code). G-code contains a set of instructions that control the movement of the tool along the linear axes (X, Y, and Z) and the machine table along the rotary axes (A and C) to produce the desired part.
5-axis layout – where it came from
It’s all thanks to French philosopher and mathematician Rene Descartes. The story is very similar to Newton’s apple. One day Descartes was lying in bed and noticed a fly. Looking at it, he realized that he could describe his position in the room using three numbers, represented by the variables X, Y, and Z-what we now call the Cartesian coordinate system. Now you may be wondering where the other two came from. In addition to describing the fly’s position in space, you can also describe its orientation. So a fly rotating around the X axis is the fourth axis, and the fifth axis is a fly rotating around the Y axis. It is also said that a sixth axis rotates around the Z axis.
5-axis-possible configurations
The configuration chosen for a 5-axis CNC milling machine determines which of the three rotary axes will be used. There are two main configurations-trunnion style machine
and rotary machines.
A 5-axis CNC tenon milling machine uses the A axis, which rotates around the X axis, and the C axis, which rotates around the Z axis, while a 5-axis CNC tilt/rotary machine uses the B axis, which rotates around the Y axis, and the C axis, which rotates around the Z axis.
The main difference between the two is how the axis of rotation is represented – in the pivot style, it is done by moving the table, while in the rotary style of the 5-axis CNC milling machine, it is done by rotating the spindle. Both solutions have their advantages, so which one to use depends on what you want to do. More than half of the parts produced with CNC require 5-axis machining, so more and more manufacturers are choosing to incorporate it into their services.
In addition, 5-axis CNC machining has many advantages over 3-axis machining, etc., such as:
Single configuration
5-axis CNC machine motion allow for a single setup of the workpiece; the machine then handles each machining operation required to create the desired part. This differs from traditional 3-axis machines requiring multiple machine setups to produce complex geometries. The single-station nature of the 5-axis CNC machine allows for the rapid machining of complex parts while reducing costs and errors that occur with traditional processes.
Shorter cutting tools and better surface finish
The fourth and fifth axes of the 5-axis CNC machine bring the workpiece closer to the tool. This means that shorter cutting tools can be used, which are less prone to vibration and provide better surface finishes.
Higher precision
5-axis CNC machines are much more precise than 3-axis machines because of the flexibility of movement, so they can produce not only smoother parts but also parts that are too complicated for 3-axis machines. 5-axis CNC machining can be used to produce many parts for which 3-axis machining is not suitable.
CNC 5-axis machining-application
Due to the efficiency of 5-axis CNC machining and its ability to produce complex shapes, it can produce parts used in various industries. Here are some examples of industries that benefit from this technology:
- Aeronautics-This industry requires very sophisticated machinery, as the shapes are incredibly complex and unique.
- Medical- 5-axis CNC machining can help medical device manufacturers produce devices, implants, and other solutions that must be manufactured with extreme precision to meet stringent requirements. It’s better than two rotational axes.
- Military- Another industry that uses 5-axis CNC machining to produce needed parts. Some possible applications include submarine components, high-performance engine components, turbine and compressor blades, smart weapons, sensors, stealth applications, and, in some cases, nuclear weapons.
- Power Equipment- Manufacturing power equipment parts often requires materials that are difficult to machine. With 5-axis CNC machining, you can make the entire process easier and more efficient, and CNC milling of complex parts will be done professionally.