How CNC Machining Has Transformed Automation in the Plasma Cutting Industry
Image by JA Huddleston from Pixabay
Plasma cutting is an evolving industrial technology that’s become a staple workhorse of proven R&D and prototyping capital equipment in metal fabrication production shops around the world.
While the cutting or subtractive manufacturing mechanisms vary between CNC machining and plasma cutting, the overall automation components like servo motors, ball screws, and controls are relatively parallel in terms of performance, utility, and programming.
After nearly a century of development, machining has enabled adjacent manufacturing and industrial processes to invent several other subtractive methodologies, such as wire EDM, CNC woodworking, water jetting, and more.
The two technologies, plasma and CNC, have proved to be sufficient in large volume production settings. Today’s automation equipment allows manufacturers to use these machines for heavy volumes or parts, large mixes of different designs, and a wide selection of metals to create components from.
They’ve also spurred creative thinking behind design and manufacturing for different industries such as plastic injection molding.
It’s not uncommon to find these machines being run unmanned, often with robotics woven into the overall process, enabling maximum throughput and efficiency.
Both plasma cutting and CNC machining have very similar procedures and workflows from an automation perspective, which has allowed manufacturing innovators to grow these two industrial technologies off of one another.
Overlaps in Technical Capabilities
There has usually been a clear, distinct gap between what a CNC machine tool is capable of, and what a CNC plasma machine is fit to handle.
For the large majority of jobs, a plasma cutter will be best suited for sheet metal, and cutting or profiling other sorts of thin material. And a CNC milling or turning machine can handle large blocks of raw material at a time, in three dimensions.
Because of this clear gap in what each machine can take on, the technologies have been able to grow in parallel, rather than competing against one another.
Difference in Material Machinability
With plasma cutting, the maximum temperature attained by the plasma is often limited by the materials it is cutting.
The same limitation is typically not present with CNC machining, which can cut through most materials regardless of their hardness and rigidity.
Because of this, there is often another distinct difference between the materials each particular machine can take on. Thankfully, as plasma and machine tools or cutting inserts have dramatically improved and have seen a reduction in cost, these types of equipment have widened the range of materials they can tackle.
2D versus 3D
Plasma cutting is largely a 2D manufacturing process for designers to create an object from a DXF, AutoCAD, or other 2D CAD drawing.
Machining was once a 2D-only technology, but it has quickly morphed into a three-dimensional process, with modern machines having at least four axes to machine with. This helps to further differentiate the technologies, while still maintaining very similar nuts and bolts.
As an example, in the automotive industry plasma cutters will likely cut out the individual body panels for cars and trucks, while a CNC machine will be used to hog out a huge block of cast aluminum to manufacture engine blocks, crankcases, and other various internal combustion components.
Plasma cutting, water jetting, or CNC routing are all viable 2D methodologies for large-scale prototyping, especially for large, flat objects that are just in need of profiling.
Feeds & Speeds
Two of the biggest variables with any CNC metal cutting process come from:
How fast the material is being fed.
The speed of the cutter or tool used to remove material.
Again, the only difference between these two manufacturing processes is the method in which the metal workpiece is being removed. The general mechanisms that drive the tool, the control that’s running the software program, and everything in between is nearly the same.
Because of that, it also helps a CNC machinist to adopt plasma cutting easily, and vice versa. Nevertheless, this allows for continuous improvements and innovations to coexist between two seemingly similar metal removal or subtractive manufacturing processes.
Overall, production capacity in CNC will usually be much larger than with plasma cutting. The widespread adoption of CNC machining has led to extremely fast and precise machines that can hold tighter tolerances, be automated almost entirely, and serve as a great means toward high volume, lot manufacturing.
Integration to Robotics
Being that both industrial technologies are computer-controlled, it makes synchronizing with robotics and other forms of automation fairly easy.
With plasma cutting, there will often be links to bending, pressing, punching, and shearing machines to automate the process of taking raw sheet metal and turning it into an end product. For CNC machining, it’s common to find pallet changing systems and robotic arms to help achieve fully automated, lights-out manufacturing, which turns out machined components 24 hours a day.
In the past decade, scaled cost of electronics, software enhancements, programmability, and general ease of use has created a perfect marriage between robotics and the CNC machining industry, which continues to allow manufacturers to do more with less.
Similar Components, Accelerated Innovation
While the subtractive manufacturing techniques and processes are worlds apart, the basic components like software and hardware that drive CNC machining and plasma cutting are almost identical. This immense amount of transferability has enabled the development of automation equipment behind the scenes to rapidly advance overtime.
What was once NC machining became CNC as both software and hardware began to evolve, especially within the metalworking industry. CAM software packages became much more robust as well, allowing programmers, manufacturing engineers, and CAD designers to understand the manufacturability of their concept or idea before actually manufacturing it.
Ultimately, these machines are all driving a tool in a similar 2D manner—the servo systems, linear actuators, and other components doing the hard work are virtually the same in each machining methodology.
So as you can see, while the two technologies are very different in their own respects, the basic automation fundamentals for CNC and plasma cutting remain the same.
Both have made tremendous adjacent innovation strides since inception many decades ago, and continue to serve as a useful means toward scaled, high-volume manufacturing production for a variety of materials, in both 2D and 3D patterns for nearly infinite applications within a variety of industries.