Differences between 3 and 5 Axis CNC Machining

machine tool in metal factory equipped with automatic drilling cnc machines

3 Axis Cnc Machining

CNC stands for “computer numerical control.” CNC machining began with simple 3-axis machines fed by direct numerical programming into the machines. However, with machining technology improvements and advances in computing, additional axes began showing up to produce tighter machining tolerance, more intricate physical geometries and less expensive parts as machine-made components can sometimes run in “lights-out” situations without an operator.

From 3-axis to 5-axis

3-axis CNC machining includes an x, y and z axis. This accounts for horizontal, vertical and depth movements. Early on, most CNC machines were limited by computing power – the servo motors required for multi access machines have been around for sometime. Big advances in computing power started occurring outside the CNC stations with the introduction of 3D CAD packages and 3D machining software like MasterCAM. 5-axis machining centers came out before 3D tool path generation software, but they had to be programmed by hand. It’s one thing to program in 3-axis, but 5-axis programming for anything smaller than large production runs was a nightmare.

Part of the growth in popularity stemmed from the tight tolerances modern 5-axis machines can achieve. Some can cut as close as 3 microns. This meant that applications requiring tighter tolerances that were traditionally hand machined could now be automated significantly lowering production costs by removing labor.

With the advent of 5-axis machining, manufacturers could implement the new method in a variety of ways, leading to a diversity of 5-axis machines. There is typically no “standard” make up of 5-axis machines; in fact, many 5-axis CNC machines are designed with a specific application in mind.

Since the invention of 5-axis machining, developers have introduced additional axes to increase functionality, but for more basic automated needs 5-axis CNC machining remains one of the more common CNC arrays.

5-Axes in Use

With five axes of movement possible, the programming needs can look daunting, but there are many basic CAD/CAM programs that can make the process go smoothly. However, simple programming entries are not exclusive when using a 5-axis machine.

Concerns

Material in a 5-axis machine must be suspended so you’ll always need to design in a substrate that can be fixtured and later removed after the part is removed from the machine. Additionally, not every job is right for a 5-axis machine. They take longer to program and are more expensive to maintain, so if you can keep your part design simple, 3-axis may be the way to go.

References

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