Plasma cutters are extremely complex machines that are required to undertake very precise cutting tasks and to complete them consistently. They do, however, operate under harsh conditions, with high levels of electricity, extreme heat and accumulated debris from cutting a variety of materials.
The environments in which plasma cutters work are very challenging, and so efforts are needed to keep them in the best working order. Proper maintenance will preserve the quality of the cut, avoid unexpected downtime and costly repairs, and extend the life of the system. A failure to maintain will, on the other hand, cause all sorts of problems and early replacement of the equipment.
How Long Should a Plasma Cutter Last?
One of the best ways to ensure your plasma cutter lasts for a long time is to buy a top-quality model and have it installed correctly. Cheap systems tend not to work very well, have sub-standard components and will need replacing long before they should do, meaning they are not cheap in the long-term. At Plazmax, we use only the highest quality of materials and construct systems properly with strict quality control procedures to ensure they are of a high standard. Check our range for features.
If properly looked after, a plasma cutter can have a useful service life of ten years or more. Sometimes, in fact, it’s not that the machine is no longer useful and effective, but that improvements in technology have made it obsolete. Rather than the plasma cutter itself wearing out, it is usually the various consumable components that become damaged or worn and reduce the effectiveness of the system.
The actual lifespan of the various consumables is difficult to predict since it depends on a number of factors. These include the number of cuts undertaken, the speed of each cut, the type and thickness of cut materials and the power used to cut them.
The consumables that require replacement most often are the electrode and the nozzle. Signs that they need replacing are poor cut quality and cutting speed, dross and spatter on the material, and an unstable arc with sparks and swirl marks on the material.
You can extend the life of consumables by using high-quality components of the correct type for each cut and constantly monitoring your equipment for signs of wear so that additional damage does not result. Always set the equipment correctly for the material being cut and create and follow a proper maintenance schedule.
What Wears Out on a Plasma Cutter?
A plasma cutter uses extreme heat and a powerful electric current to cut metal. Many of the consumable components are exposed to these, and there can also be instances of blowbacks and exposure to contaminants that can damage them. These component parts need to be changed periodically to keep the cutter working well. They are:
- An electrode is made of copper and hafnium alloy that conducts electricity well and has a high melting point. An electric current is sent through the electrode to the material being worked on, the electric arc creating the plasma. The current and the heat eventually melt the hafnium so that the electrode becomes pitted and misshapen. If the pitting exceeds 1-1.6 mm, the electrode should be replaced to prevent damage to other components and to restore cutting quality.
- The nozzle covers the electrode and focuses the plasma jet into a suitable shape for the cutting type. Different nozzles can be fitted for varying cuts, but they are exposed to extreme heat and can be damaged when changed. It is usually a good idea to fit new nozzles and electrodes at the same time so that the cutting quality is restored.
- The swirl ring has perforations that direct the gas flow to create the ‘tornado effect’ within the plasma jet. Cycles of heating and cooling can cause it to crack, and the perforations can become clogged, necessitating replacement. Even with no obvious problems, it is good practice to change the swirl ring at each fifth electrode replacement.
- The retaining cap covers the torch, holds the components together and shields the nozzle. It will wear eventually and can sustain damage and backsplash during cutting. Any slag should be removed to achieve consistent airflow, and the cap will need to be replaced if build-up becomes too great.
As when buying a complete system, always use the highest quality of components. These will work best, last longest and help to prolong the life of your plasma cutter.
How Can I Improve My Plasma Cut Quality?
Sometimes cut quality can be influenced by material preparation and the parameters set for cutting. Ensuring these are correct will mean your cuts are as good as they can be. Proper operator training is essential for maximum operational efficiency.
The quality of the cut becomes poorer than usual when the edges are jagged and uneven, and the cut is not within normal tolerances. The result may be more wastage or additional work to clean up the material. The problem is often due to damage or wear of the nozzle, usually when the hole at its tip becomes larger so that the plasma arc is thicker and the resulting cut is wider.
A quick visual inspection will determine if the hole is too large and, if so, the nozzle needs to be replaced. Damage or wear of the electrode will also make cutting difficult, so replacement of both these components will almost certainly improve cut quality.
Another key factor is gas supply. Low gas pressure can lead to incomplete cuts, increased dross, and poor edge definition, while contaminated or moisture-laden air can damage consumables prematurely and create inconsistent arc performance. Using clean, dry, and correctly pressurised gas is essential for producing a smooth, accurate cut.
Making sure that all your components are in good order will sustain a high quality of cut. So inspect them all regularly, possibly before each cut, and replace when necessary.
How to Maintain a Plasma Cutter
Regular inspection and maintenance of your plasma cutter are essential because they will:
- ensure a consistently good cut quality and enhance the overall performance of the system
- increase the lifespan of the system since fully working parts will prevent damage
- reduce costs because identifying and resolving a problem early will ensure it does not become bigger and more expensive
- eradicate safety hazards by fixing loose connections and other faults
- improve productivity by preventing unexpected breakdowns and having only planned downtime at convenient periods.
To keep your system running at peak efficiency, follow the manufacturer’s instructions and:
- Clean it regularly, after first disconnecting from the power supply to prevent accidents. Wipe down the external surfaces using a damp cloth. Remove debris from the cutting surface and use compressed air or a soft brush to clear dust and dirt from the components. Pay particular attention to the torch leads, the torch assembly, electrode and swirl ring, plus filters and the cooling system, if fitted.
- Make sure the rail sections and bearings are properly aligned, with no gaps between gears and racks, which will improve efficiency and cut quality.
- Lubricate all moving parts, such as the rails and bearings, ensuring there is no excess that will attract dirt. Lubrication will reduce friction and prevent wear.
- Check the power supply and grounding by first removing the cover and then using compressed air or a vacuum cleaner to remove dirt that can damage internal components. Make sure the power supply and ignition console are correctly grounded and check the fans and filters for wear and damage, replacing them if necessary.
- Ensure air filters have no signs of oil, moisture or particulates and, if discoloured or dirty, replace them. If a cooling system is fitted, check the coolant level and top up if necessary. If the coolant is grey or black, this is a sign that the pump may be failing and needs to be replaced.
- Replace component parts if they have reached the end of their serviceable life or appear worn or damaged, which will ensure efficient operation and prevent unexpected downtime.
- Tune the drive motor and control if there are issues with torch positioning. This should not be attempted unless you have the required technical expertise because it is a time-consuming job, and you need to be familiar with the inner workings of the equipment.
Regular inspections and maintenance are tasks that can be scheduled for a convenient time, which is much better than having to carry out repairs due to an unexpected breakdown. Always keep a record of maintenance, with dates and details of issues and parts replaced. This will help to identify frequent problems and mean you can plan future maintenance.
Following a proper maintenance schedule is essential because it will keep your machine working at peak efficiency, prolong its life and save money by resolving issues before they become serious. Although you can carry out some of the cleaning and maintenance yourself, this may not be the best use of your time and is often better undertaken by a professional.
We can provide a preventative maintenance schedule that is tailored to your needs. Our experienced technicians will recognise problems early, rectify them promptly and ensure your system works well at all times. Get in touch to find out what we can do for you.