How to Reduce Wear and Tear on Your Plasma Cutter
Plasma cutters, like any machine using electricity, can be a powerful tool in your workshop. However, it can also be a safety hazard, particularly if it’s not properly maintained. Ensuring that your plasma cutter is in good working order, maintaining various parts and replacing consumables as necessary, and giving the whole system a regular inspection is critical to avoiding injury, not to mention the chance of faulty cutting, poor operation, or unnecessary repairs or replacement of the machine.
What should be on your plasma cutter maintenance checklist? How can you avoid unnecessary repairs? Read on to learn more.
What Are the Benefits of Good Plasma Cutter Maintenance?
In case you’re unsure of why you should be investing time and energy into maintaining your plasma cutter, here are the benefits, itemized.
First, it will perform better. By keeping your plasma cutter clean and well-maintained, you help ensure that you consistently get clean, high-quality cuts. Any dross, slag, old consumables, or debris can get in the way of the plasma jet formation, lead to inconsistencies in current or airflow, and can leave you with inaccurate, jagged, or otherwise poor quality cuts. While this isn’t strictly necessary for something like deconstruction of a larger piece, it’s critical for the precise needs of CNC plasma cutting and fabrication.
Second, and what is most relevant to most people, it will cost less over time. Preventative maintenance is a huge benefit when it comes to the lifespan of a machine. If a poorly-maintained machine burns itself out after three years, and a well-maintained machine lasts for ten, you’re already coming out way ahead. Maintenance also allows you to keep a machine operating with minimal investment; cleaning is a lot cheaper than replacing parts of the torch or feed system when they break.
Third, it’s a safety concern. Plasma cutters use high electrical currents – a danger – to create extremely hot jets of plasma – a danger – to melt and blast away metal – a danger – and all of this has the potential to go terribly wrong. While proper caution and PPE are important as well, proactively reducing the chances of an accident is also critical.
Finally, though this is minor; you can plan your downtime. Taking a machine out of service for a thorough cleaning and maintenance review is something you can plan your schedule around, whereas something breaking and requiring maintenance in an emergency is going to be both a longer downtime and a worse interruption to your productivity.
So, what should go on your maintenance checklist? Here are the major items to cover.
Clean Your Plasma Cutter Regularly
Cleaning a plasma cutter can be a complex task. You need to clear out the remains of past projects, like drops of hardened dross. You also need to clean out dust, fume residue, and particles that accumulate. Moreover, a plasma cutter needs to be kept cool, which means you likely have filters to clean out as well.
Cleaning should be done in three forms.
The first is the routine, daily, before-every-use once-over cleaning. A dry rag, compressed air, chemical cleaning solutions, and even wire brushes may be necessary for this. You cover the bases, checking the torch, the cutting surface, and other elements that are likely to get contaminated in the course of operation, and make sure they’re nice and clean before starting a new project.
The second is the frequent, but not daily, once-over cleaning. This might be weekly, or it might be monthly, depending on how frequently your plasma cutter is in service and how much of a workload it handles. This is where you do things like wipe off the main machine, clean out filters, and do a deeper clean of connections, nozzles, the surface of the machine, and more.
The third is your sporadic deep cleaning. This might be quarterly, once every six months, or once a year, depending again on the level of active use the plasma cutter is under. This is where you use every tool at your disposal to clean the machine inside and out. Whether it’s examining hoses and junctions, cleaning out connections and feeds, deep cleaning the nozzle, or opening up and blasting out the interior of the machine, this is a very thorough cleaning.
One note: the deep cleaning may need to be performed by a skilled technician on some machines. This is especially true for the larger and more complex CNC-style plasma cutters, which can be both quite complicated and surprisingly fragile. You may also need to run calibrations after cleaning and reassembly, to make sure nothing was nudged out of position or miscalibrated during the cleaning process.
Keep an Eye on Consumables
Plasma cutting has a number of consumables. While you aren’t filling it up with fuel and burning through it like you would a generator, a plasma cutter does still have parts that are exposed to the high heats and currents of the plasma jet itself, as well as the possibility of blowback slag and other contaminants. These can be damaged through use and are expected to be discarded and replaced periodically.
Thus, a big part of your plasma cutter preventative maintenance should be examining and, as necessary, replacing these consumables.
Pro tip: Keep a stock of consumables on hand. If a misconfiguration of the CNC software, a stray piece of slag, or other damage unexpectedly requires replacing something critical in the torch, you don’t want to be left stalled with the pieces on order, even if they’ll ship quickly.
So, what are the consumable parts of a plasma cutter, and how long are they expected to last?
The Swirl Ring is a component inside the torch that directs the gas pumped into the machine to create the “tornado” part of the plasma jet. It’s a piece of metal with perforations that guide and direct airflow. Over time, this piece can get gummed up, the holes can get plugged, and its efficiency will drop. It can also crack over time as it is exposed to cycles of heating and cooling with each use.
The Electrode is perhaps the most important part of the plasma cutter. It’s a copper and hafnium alloy that conducts electricity very well and has a high melting point. Electrical current from the torch is sent through the electrode and to the workpiece, and the arc is what generates plasma in the swirling gas. Electrodes are the primary consumable, because that current and heat from the plasma will slowly melt the hafnium in the alloy and can lead to pitting and misshaping of the electrode.
The Nozzle is a cap that goes over the electrode and the rest of the torch. It focuses and guides the plasma jet into a specific shape suited to the kind of cutting you will be performing. Different nozzles can be switched in and out to suit different needs in cutting, like wider, deeper, or more directed plasma jets. Nozzles are the primary consumable you’ll need to switch other than the electrode, both because they are the most directly exposed to the hazards of plasma cutting, and because their swappable nature means they can be damaged in handling as well.
The Retaining Cap is a piece that covers the rest of the torch and acts both as a retainer to hold it all together, and as a shield. Only a small bit of the nozzle is exposed (though that still can damage the nozzle), and the retaining cap takes the brunt of any backsplash or other damage. It can wear out over time, and can absorb damage from the cutting process, so it needs to be replaced from time to time.
So, how long do each of these parts last? Unfortunately, there’s no simple answer. It depends on the kind of cutting you’re doing, and how much of it you’re doing. You’ll tend to notice that your cutting path ends up wider and less clean over time; this is a sign of consumables degrading.
“It’s hard to be specific about exactly when you’ll need to replace your nozzle and electrode, as this will depend on many factors, including the speed you cut, the thickness of the workpiece and the amount of amperage you use. However, it is a good idea to replace your nozzle and electrode at the same time (according to whichever wears out first), as this will put you back to optimum cutting performance, rather than using a new electrode with a worn and inconsistent nozzle, for example.” – Esprit Automation
Generally, you need to replace your consumables when one of three things happens:
- The quality of your cut is no longer within acceptable tolerances.
- Handling or damage makes it difficult to appropriately swap nozzles or other parts.
- Slag and other backsplash damages a piece, requiring its replacement.
The timeline for these is variable; just keep an eye on the quality of your plasma cutting and replace the parts as necessary.
Inspect and Clean the Cooling System
Since plasma cutting is an operation that uses electricity, that electricity needs to be transformed into a usable form, whether it’s coming from a generator, an appliance-grade three-phase system, a 240-volt wall plug, or a standard household connection. This generates heat, along with the actual heat of the cutting process. This means the entire system needs to be kept cool so it can continue operation.
A plasma cutter’s cooling system will generally use some kind of coolant to carry heat away from the heat-generating components and to a radiator, often with a fan that blows air past it to remove the heat. Coolant can be consumed slowly over time, and it may need replacing periodically. Check the manual for your plasma cutter to know exactly what coolant you should use and how often to check and replace it.
Some plasma cutters also use water, either as a coolant or as another part of operation. If this is the case, make sure you’re using clean water, as water with contaminants in it can lead to mineralization build-up and damage to the entire system, in a way that requires replacement rather than cleaning.
Clean and Grease Moving Components
This one is specifically for the mechanized CNC machines; handheld plasma cutters don’t have them. These systems are the pieces that move and control the torch and workpiece. Dust, slag, and grime can build up on gears, in chains, and along rails, which can lead to shaky operations, friction, slower motion, and even total failure. Make sure to routinely degrease, clean, inspect, and re-grease these components every 6-12 months, or as often as the manual for your machine recommends. Make sure to use the proper kind of lubrication, like graphite powder, according to the instructions once again.
Make sure that when you reassemble your machine, you level, align, and calibrate your rails and drive system. Computerized systems rely on the machine being accurately calibrated; the software isn’t using your part as a reference, it’s using the machine itself. If anything is misaligned, your cuts won’t work properly.
Check Safety Features
Different kinds of cutting torches will have different kinds of safety systems, from interlocks to circuit breakers to limiters on the motion of the torch. These all need to be in good working order to ensure the smoothest and most effective operation.
Make sure to routinely inspect these to make sure nothing is out of bounds, bypassed, or wearing into a safety hazard.
Let Us Handle The Maintenance
While we don’t directly perform maintenance on your equipment, we do on ours; if you want to rent a plasma cutter from us, we’re more than happy to oblige.
Simply rent a machine from us and, when it comes time to perform maintenance, return it; we’ll maintain it, and you have the opportunity to rent a different machine to try, re-rent the same machine, or even purchase the used machine for permanent installation in your shop.
With a variety of plasma cutters available, we’re certain to have something that works with your shop and your needs. We also have a wide range of welding systems, and everything you need from a small, individual machine all the way up to a turn-key automated fabrication facility. Just drop us a line and we can get started!
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