Speed, efficiency, and versatility are three key benefits of 6-axis CNC machining. Thanks to this novel technology, machinists can fully automate the subtractive manufacturing processes of complex geometries in much shorter times and without needing to cease each operation to reorient the workpiece for the next operation. Below, we’ll talk about each of these benefits in more detail.

Speed

Cutting times are way faster in 6-axis CNC machines compared to closely-related 5-axis configurations. With an additional axis of freedom, certain tool movements and transitions can be executed with greater speed and efficiency. According to Kingsbury, a longtime supplier of industrial machines, 6-axis milling can decrease cutting times by as much as 75% – four times faster than 5-axis configurations.

Zimmerman milling solutions, a German manufacturer of popular 6-axis milling setups, published a video comparison of 5-axis vs 6-axis milling. We highly recommend checking it out; the buttery-smooth actuations of the toolhead are mesmerizing.

Versatility

6-axis CNC machining enables many subtractive manufacturing operations in a single machine unit: milling, grinding, grooving, facing, drilling, parting, and turning. Thanks to all these automated processes, you’ll achieve your desired shape with the highest possible precision and accuracy.

Efficiency

As the geometry becomes more complex, the efficiency of 6-axis CNC machining also increases. Since 6-axis is highly capable of various machining operations in one instance, it’ll be more efficient for complex parts requiring many operations than parts with simple geometries. If it’s simple, it can be done with a 3-axis mill.

So what’s the point in investing of a 6-axis machine? A 6-axis configuration offers smoother motor performance, which leads to less waste, higher accuracy, and better surface finishes. Rotation of all three axes enables the carving of curves and helixes much more easily. Further, according to Rapid Enterprises, 6-axis machining softer materials like aluminum, wood, and thin steel is more efficient since the chance of deformation and problems related to heat from friction decreases.

Despite their advantageous points, 6-axis CNC machines have downsides, too. Due to their sophisticated technologies, expanded features, and expense, operation and maintenance are costly and require high levels of expertise. Regular manufacturers rarely opt for them since it’s not beneficial for their budget unless the part can’t be machined with simpler configurations.

Cost

Adding just one more rotation axis makes the resulting mill much more complex than its 5-axis counterpart, which in turn dramatically increases its operational cost. Rapid Enterprises estimates that this machine will cost in the range of $3,000 for lower-end models and up to $500,000 for the most advanced industrial-grade machines. However, you’ll need to contact the 6-axis manufacturers directly for precise quoting.

In addition to the cost of the machine itself, its ongoing maintenance is also expensive, as is repairing or replacing parts. Don’t forget about the control software: As it’s also very special, the software carries a higher price tag than regular software used for lower-axis configurations.

Rarity

If you’re just machining a small perfect cube from a perfect block of raw material, 6-axis milling doesn’t have any advantage over a 5-axis setup. After all, if the cuts are all straight (vertical), rotations about X- and Y-axes aren’t needed anyway – let alone rotation about Z-axis.

The only place you’ll find 6-axis CNC mills is in the high-end industrial setting where most of the components to be manufactured are quite complex. Such parts require at least five axes of machining freedom. That’s when 6-axis CNC milling shines. Complex geometries like turbines or engine blocks are all fair game.

Expertise

The increased complexity of this machine will require an expert machinist who is well-trained and experienced to operate it. Even performing routine maintenance operations like tooling adjustment will require specialized expertise.

Various industries, particularly those dealing with complex parts, are scaling up their adoption of 6-axis CNC machining technology to increase the quality of their parts while cutting down production time. It has revolutionized the production of long components in aerospace, gears in automotive, and implants in the medical industry.

In the aerospace industry, machinists use these 6-axis machines to fabricate critical parts such as cockpit and airplane wings. For example, the Kansas-based company Triumph Structures makes aircraft parts – some of which are as long as 80 feet – from titanium, aluminum, and hard metals. The company claims that it has cut down the cycle time of aircraft components by 35%, thanks to its 6-axis CNC machining capabilities.

In addition to a variety of 3-, 4-, and 5-axis CNC machines, Triumph has a 6-axis FZ100 machine with twin gantries developed by Zimmermann. FZ100 was initially a single-gantry machine, but Zimmermann modified it in response to Triumph’s request.

Similarly, the automotive industry has benefitted from 6-axis CNC, which allows for efficient and precise fabrication of vehicle parts, especially if drilling, milling, and turning processes are involved. The turning and milling operations enable manufacturers to cut gears from cylindrical workpieces.

A notable example of 6-axis applications in the medical industry includes implants. Dental implants, for example, need to be as accurate as possible so that they fit the actual tooth root in the gum. Thanks to its precision, 6-axis machining gives a huge boost to the creation of precise implant shapes. This also applies to surgical and prosthetic implants, where precision is a key factor.

As you can see, 6-axis CNC machining is a specialist’s art. With some of the most well-known companies for 6-axis milling machines, Germany is a global leader in this technology. Here’s a look at three of the companies:

• Zimmermann provides many of the rare 6-axis CNC mills out there. As we mentioned above, the custom-built machine for Triumph Structures features two gantries, each holding a 3-axis head, to create a larger 6-axis mill. In addition to specialized solutions, the company offers a range of 5- and 6-axis milling machines, some of which are available on short notice.
• MATEC manufactures a high-precision machine capable of machining long workpieces on five sides, thanks to an integrated rotary table acting as the 6th axis. It’s perfect for turning, gear cutting, and deep-hole drilling operations. The machine has two performance varieties with maximum powers of 30 kW and 50 kW.
• LT Ultra also manufactures 6-axis milling machines. Its MMC H (short for “micro milling center hydrostatic”) series machines are basically set up with three linear axes but can be upgraded to become 4-, 5- or 6-axis by adding rotary, tilt, or spindle axes. The machines come in two versions: either 600H for a maximum travel of 600 mm along the X-axis or 900H for maximum travel of 900 mm.

Choosing a suitable CNC machine depends primarily on the geometrical complexity of the parts you want to produce, as well as your production volume and budget. 5-axis machines offer the same capabilities as 6-axis ones but at a fraction of the price while requiring less training and skills. However, they’re slower and less accurate than 6-axis machines. In some cases, even a 3-axis machine will meet most of your basic machining needs – but also with trade-offs.

6-axis machines are still pretty rare. They’re only used in high-end industrial settings, and few of us work in commercial aircraft factories. Still, if you’re in the market for a 6-axis machine, you now know a bit more about its pros and cons. For the rest of us, we’ll have to settle for a little less rotation.

All About

CNC Milling