The main difference between 3-axis, 4-axis and 5-axis machining is the complexity of the movement both the workpiece and the cutting tool can move through, relative to each other. The more complex the motion of the two parts, the more complex the geometry of the final machined part can be. For example, a 3-axis machine can only move the workpiece and cutting tool in straight lines relative to each other, so only simple geometry can be machined. However, a 4-axis machine can also rotate the workpiece on one axis as it moves along another, allowing for more complex geometry to be machined. Similarly, a 5-axis machine can move and rotate the workpiece on two axes simultaneously, allowing for even greater complexity. In general, 3-axis machining is limited to fairly simple geometry, while 4- and 5- axis machining can produce much more complex shapes.

## What are axes?

When we talk about axes in reference to a CNC machine, what we’re really talking about is the different ways the machine can move a cutting tool or workpiece. The most basic linear axes are the X-axis, Y-axis, and Z-axis. X refers to vertical movement, Y to horizontal movement, and Z to depth – i.e., movement from front to back. All CNC machines are built around those basic Cartesian axes. Today, the more advanced machines add in a 4th or 5th axis to expand the range of what’s possible without re-mounting a workpiece. The 4th axis is typically a rotary axis that allows for circular cuts to be made, while the 5th axis provides even more freedom of movement, allowing for conical or curved cuts. With these additional axes, modern CNC machines are capable of creating almost any kind of shape imaginable.

## What are 3-axis machines?

A 3-axis machine is a milling process that operated on two axes, the X & Y axis. In three axis machining, the workpiece remains still while the cutting tool moves along the 3 axes to mill the part. The term “3-axis” refers to the number of linear degrees of freedom that the machine has. The three axes are typically labeled as follows:

X – horizontal

Y – vertical

Z – depth or height

The X-axis is parallel to the workpiece surface and perpendicular to the Y and Z axes. The Y-axis is also parallel to the workpiece surface, but is perpendicular to the X and Z axes. The Z-axis is perpendicular to both the X and Y axes and is also parallel to the workpiece surface. Generally speaking, a 3-axis machine can only mill parts that have rotational symmetry about the Z-axis. This means that most 3-axis machines are limited to milling cylindrical parts, although some can mill prismatic parts as well. Parts that do not have rotational symmetry about the Z-axis, such as square or rectangular parts, can only be milled on a 5-axis machine.

## What are 4-axis machines?

A 4-axis CNC machine is a machine that operates on the X,Y, and Z axes. The fourth axis is the A-axis, which is the rotation around the X-axis. This fourth axis allows for cutting to occur around the B-axis. In most cases, the workpiece is rotated to allow for this to happen. There are many benefits to using a 4-axis machine, including the ability to create more complex shapes and the ability to reach tight spaces. When it comes to machining, a 4-axis machine is a powerful tool that can help you get the job done right.

## What are 5-axis machines?

What are 5-axis machines? Five-axis machines take it one step farther, adding a second rotating axis, usually the B-axis. X-Y-Z-A-B, or X-Y-Z-A-C, will rotate around both the X and Y or X and Z axes. In practice, that looks something like this: The workpiece can be moved in nearly any direction, allowing full range cuts to be made during a single operation. Add in a tool head with multiple cutters, and the design possibilities are nearly endless. Adding those fourth and fifth axes vastly expands the range of designs you can build with a CNC machine. And that’s the key difference – the design. With 5-axis machines, interior cuts, angles, and unusual finishes are all possible.

Five axis machining is a technology that has greatly increased the range of products that can be created using CNC machines. What is five axis machining? It is a method of controlling a machine in which the workpiece can be moved along five different axes simultaneously. This allows for much more complex shapes to be machined than was previously possible with three axis machines, which can only move along three axes (x, y, and z) at once.

Adding a fourth and fifth axis to a CNC machine opens up new possibilities for designers and engineers alike. When combined with other advanced technologies such as 3D printing and CAD/CAM software, five axis machining provides nearly limitless potential for creating unique parts and products. If you are interested in learning more about five axis machining or other CNC technologies, contact us today. We would be happy to answer any questions you may have.

## What are the different design capabilities with 4- and 5-axis machines?

3-axis machines are limited in their design capabilities when compared to 4- and 5-axis machines. With a 3-axis machine, it is only possible to machine all 3 axes on a single planar surface. This means that angled workpiece features become challenging to cut, as the workpiece must be mounted in an unusual way in order to access the different sides. Additionally, it is not possible to cut complex designs with a 3-axis machine.

4- and 5-axis machines expand the range of motion and make it possible to cut almost any design. With these machines, it is easier to Cut complex designs and angled features, as the workpiece can be rotate on multiple axes. This prevents the need for re-mounting the workpiece in order to access different sides, which saves time and increases efficiency.

## When to use a 3-axis, 4-axis, or 5-axis CNC machine?

When it comes to CNC machines, more axes doesn’t always mean better. In fact, for many tasks, a 3-axis machine is all you’ll need. If you’re focused on cutting key slots, grinding out surface features, and drilling shallow holes, then a 3-axis machine is up to the task. It’s worth noting that angled features can be cut on a 3-axis machine – they just require more planning and more frequent mounting/remounting. When your project moves beyond basic machining and into multi-surface workpieces or cylindrical shapes, then it’s time to step up to a 4-axis or 5-axis machine.Adding a rotating axis to a CNC mill gives it many of the same capabilities as a CNC lathe. Both workpiece and cutting tool can rotate, meaning that a 4-axis milling machine can be used for surface work on cylindrical shapes.

And to go back to our earlier example – if you need to cut an identical feature on every surface of a block, a 4-axis machine saves you the trouble of remounting the workpiece multiple times. When your project requires the utmost in precision and complexity, then it’s time for a 5-axis machine. These machines are capable of machining surfaces at virtually any angle, making them ideal for creating organic shapes and highly intricate designs. So when it comes time to choose a CNC machine, be sure to select the one that best suits your needs.