Recently invested in a CNC plasma cutter and want to prolong its lifespan? The standard best practices call for timely maintenance and proper handling. But rarely does anyone talk about consumables, i.e., the plasma cutter components that wear over usage and time. Keeping on top of them is essential if you want to achieve high-quality cutting project after project.
What are plasma cutter consumables?
In simple terms, plasma cutter consumables are a set of components that undergo natural wear and tear and need to be replaced over time. All these components are present inside the cutting torch where the plasma energy is focussed, so they get exposed to the high temperatures of the plasma arc.
Proper care of these consumables is critical for high-precision cutting. If any of the consumables wear out, it can result in imprecise size, edge quality or bevel.
What consumables reside in the plasma cutting torch?
The main consumables are, nozzle, swirl ring, electrode, shield cap, and retaining cap. Here’s a detailed breakdown of each.
The nozzle is the fine tip that focuses the arc on the cuts and plates. Nozzles can have different widths, with finer nozzles often used for detailed and intricate work. A large opening nozzle is best for situations where the operator needs to perform gouging.
The nozzle creates a high-velocity column to help compress the plasma arc. The compressed arc is responsible for cut accuracy, quality, and speed.
Made from volcanic ash or ceramic, a swirl controls and swirls the gas around the plasma arc. It also controls the point the emitter connects to the arc. The layer of gas helps to direct and focus the arc for better cutting precision, while swirling promotes cooling. The cooling helps slow down degradation and prevents the nozzle from burning. Moreover, the swirl ring aligns the nozzle orifice and emitter and insulates the nozzle from the high-frequency energy of the electrode.
The electrode is a piece of copper or silver containing hafnium, an excellent conductor of electricity. HF is responsible for starting the arc and keeping it centered on the nozzle orifice. Other internally machined components (Step and Bore) allow for uninterrupted coolant flow throughout the electrode to increase the life of hafnium.
The electrode’s main purpose is to carry current from the torch to the plate, which arcs the plate after going through the stages. Additionally, the electrode conducts high-frequency energy at the initial stage of the cut, which helps ionize the cutting gas, produce plasma and kickstart the arc.
The shield cap is meant to secure the torch and its components from the molten metal and spark resulting from the plasma cutting process. It’s the largest consumable and ensures a proper standoff distance between the work piece and the nozzle. The shield cap takes the brunt of the fallout, protecting the other components from wearing out completely.
The retaining cap holds all the other plasma torch consumables in place. Because temperatures at the torch end of the machine get extremely high, this component bears a lot of heat and degrades over time. Although many plasma torches have shield caps made from materials capable of withstanding high temperatures, the part is expected to wear out with consistent cutting.
How to prolong the life of the consumables
Ensure the components are properly and neatly installed in your plasma machine. Ideally, consumables should be well-assembled, and their tolerance should match the amperage you use.
Work within the correct parameters to attain maximum efficiency. Cutting too fast, too slow, or at the wrong distance can make the components wear out faster than they should.
Pierce at a proper height, 1.5-2 times the correct torch-to-work distance. If you pierce too low, spatter blown back can harm the nozzle after only a few runs. Piercing too high can cause premature nozzle damage and excess pilot arching. That’s why achieving the proper pierce height is critical.
Keep tabs on the consumables and their condition. Immediately replace any worn-out component with a fresh piece so that other consumables remain unaffected. Try changing the electrode and nozzle frequently, so they don’t affect the cut quality.
At Squickmon’s we always strive to provide the best options and quality within the light industrial market. Check out our plasma cutter consumables, upgrades, accessories and machine add-ons that will help extend the life of your plasma cutter.