How To Repair A CNC Plasma Cutter:
5 Key Issues Solved By Experts

For most manufacturers, their CNC plasma cutting machine holds a key position in the production process. Often running at very high to max capacity it constitutes a bottleneck point.

So the moment this crucial machine isn’t working, production stops, which means costs start accumulating fast. Downtime is a manufacturer’s worst nightmare and if it happens repairing that machine immediately becomes a top priority.

So when broken, how can you repair a CNC plasma cutting machine asap? Can and should you repair the machine yourself, and where can you find expert help?

The fastest way to repair your CNC plasma cutting machine is to get an authorized technician, preferably one linked to a leading plasma machine producing company. An official mechanic will not only have the expertise to identify the issue or issues, but he will also have the needed spare parts at hand to enable a fast repair, enabling production to resume as fast as possible.

Esprit Automation technician repairing a CNC plasma cutter

Plasma cutting machines are extremely complex machines, consisting of several intricate mechanical and software systems that rely on each other to deliver high-performance cutting results.

Therefore, proper repair is critical to ensure you avoid decreased cut-quality, excessive downtime or machine damage.

As there could be many different reasons why a CNC plasma cutter isn’t working, we will explain in this article what to do in case you experience one of the 5 most common issues with a CNC plasma cutter and how you can get the best expert help for the reparation of your machine.

What to do before repairing a CNC plasma cutting machine
Where to get expert help?
Avoid future breakdowns with preventative maintenance service

What to do before repairing a CNC plasma cutting machine?

So if a plasma cutter isn’t working, there could be many different reasons why this is the case. So the first step is to try and figure out what the nature of the issue or issues so you can zero down on the components or systems that need repairing. In the next section we will help you diagnose the issue by going through the 5 most common problems.

Secondly, never forget that plasma cutting machines require adequate vigilance and precaution. Utilizing incredibly high voltages and generating powerful plasma arcs, these machines need to be handled in a responsible and safe way.

That is why before you start any repairs on your plasma cutting machine you should ensure the following safety precautions are in place:

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1. Disconnect Power

Make sure all the power is turned off, and the different gas flows are secured.

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2. Discharge Capacitors

There are extremely high voltages and currents inside a plasma cutter, so also make sure all the capacitors are discharged.

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3. Foresee Ample Work space

Ensure you have ample working space around the machine. Make sure you are to work in a safe way (e.g. not in the path of passing forklifts). If possible effect repairs outside of production hours.

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4. Foresee A Work Bench

Foresee a large and clean surface to place any components, bolts or tools.

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5. Wear safety gear

Wear adequate protective gear such as a safety helmet, glasses and gloves.

A clean working environment is really important

Prepare yourself & foresee a clean working environment

1. Start-up issues

If your plasma machine doesn’t start up, don’t start panicking just yet and immediately opening up the machine itself. Always first check whether all the power and gas lines are properly connected. Also, check the fuse box to see whether power is still being supplied to the machine.

It would be the first time technicians have wasted significant time closely inspecting each interior components and system to eventually find out power wasn’t connected correctly.

Check if the gas lines are well connected

Check if the power & gas lines are well connected

2. Issues with the plasma arc & torch

If your machine starts up normally but you are seeing inferior cutting quality this might be an indication that something burned up on the inside. In this case, a next step would be to open up the torch and check the leads.

The most common issues are those relating to the plasma torch & consumables. If certain components are damaged or burned out, the plasma arc will be disrupted or stopped, leading to quality issues or even a full shutdown.

A healthy arc is bright-white to light-blue in colour. If it starts to turn orange or purple, it could be a sign of contaminants in your gas.

A green arc is a red flag, indicating that you have burned through the tip on your electrode and are now burning (and melting) copper. If your arc turns green, replace your consumables immediately to avoid full torch failure.

CNC Plasma cutter Arc Flame colors and when to change

However, the failure of one component can lead to more severe damage throughout the torch. In this case, you might need to replace the full torch.

To check this, carefully remove the torch from its mounting tube and open it up.

Remove any accumulated metal dust or other particulates using compressed air and if needed a cotton swab.

Closely inspect each component. Look for small cracks, burned areas or other signs of mechanical wear. If the wear-out is contained to a certain consumable or part, replace it. In case the damage is spread throughout the full torch replace it in its entirety.

Replacing consumables is a fairly easy thing to do and part of the routine maintenance of your plasma cutting machine.

When replacing consumables or torches, remember: only use the correct & genuine parts for the job.

Cheap unauthorized parts will usually not last very long and inferior quality might even cause harm to your machine.

Make sure all of your CNC plasma consumables are seated correctly in the right places and components are re-assembled correctly.

Consult your operator’s manual, and follow its recommendations for maintenance.

Genuine plasma cutting consumables are always prefered

3. Mechanical Issues

If you notice any motion of the machine is inhibited in some way this could indicate a mechanical issue, which is related to the hardware itself.

Examples include issues with the rail base system, X-Y movement problems, the torch not returning properly to its start position, deviations in torch height, or other movement constrictions and problems.

As a first step, a mechanical engineer could do a first check and if he or she is able to spot & repair the mechanical issues.

Check whether the rail system is still perfectly aligned as misalignment can cause drag of the drive motors. Also double-check gears and bearings for misalignment or obstruction by dirt or other particles.

If you are facing larger mechanical issues and you or your mechanics are not sure where exactly to start, it might be better to call in expert help.

Also, note that some mechanical problems can just be the manifesting symptom of an underlying software issue. Again this calls for professional expertise to ensure proper repairs.

Check whether the rail system is still perfectly aligned

4. Plasma system Issues

If the plasma arc doesn’t fire up or the system doesn’t start in its entirety you might have an issue with the plasma system itself. The plasma system is an extremely complex and delicate system. We strongly recommend to only have authorized technicians open and repair these systems. Avoid tampering at all costs, you might make the problem inadvertently worse. However, in case your plasma system doesn’t start you can always try to reboot the system. Just make sure you turn off all power, double-check all leads, connections, and grounding. If a reboot didn’t resolve the problem, or in case you are facing more complex issues with your Hypertherm or alternative plasma system (e.g. insufficient power being generated, rattling noises, etc), always refer to expert help to ensure professional and safe repairs.

Hypertherm-Plasma-Systems-for-Esprit-Automation

If rebooting doesn’t work, always contact an authorised technician

5. Software Issues

In case the plasma machine still starts, but the controller is giving one or multiple error messages, inhibiting any further action you are most probably dealing with a software issue. Software errors related to automatic safety systems, like issues with gas flows, can be resolved easily. Just repair the underlying physical issues related to the error message. Other software errors can be more complicated and will require more in-depth understanding of the CNC controller and/or motion software. In case you are seeing any error messages when starting the machine, and the error is not a warning relating to physical safety checks (e.g. issues with gas flow or coolant level), always first try to fully shut down the system and restart it once again. If you reboot the system and the error persists, we would advise you to contact your CNC software supplier for assistance. Avoid trying to repair or tinker with CNC plasma cutting software if you are not an authorized software engineer. These are complex pieces of software and most suppliers will not guarantee warranty or support if they find evidence of outside tampering. To note, with industry 4.0 software solutions such as IRIS, software issues will be even more easily tracked and because the supplier often has direct access to the system and logs, the problems can be identified and resolved very fast.

Request Cutting samples from your OEM Plasma cutter manufacturer

Machine Health information with IRIS

Where To Get Expert Help?

Let’s face it, a mechanized plasma cutting machine is a very complex piece of machinery.

Although you might be able to repair minor mechanical issues yourself (e.g. a broken plasma torch, removing obstructions from bearings and rails), more severe problems such as problems with the drive motors, the plasma system or the software are better left to experts.

When it comes to issues with the internal mechanics of the machine, you can find many small companies as well as independent contractors online that offer their services for a range of machinery.

However, we would strongly recommend opting for the service support of your plasma cutting machine manufacturer.

Their service might be a little more expensive vs. independent contractors, but they have two major advantages:

They can count on highly specialised technicians specialized with years of experience in repairing plasma cutting machines. Most of them even support on a range of brands, not just their own.
They also have stocks of replacement parts at hand which means they are able to resolve the issues very fast or even on the spot, while independent service technicians might need to order specific components.

For software related issues, you are best to contact the developer or supplier directly. To note, some general software solutions such as Camduct are actually also sold & supported by local distributors. These local distributors are usually faster in their response vs large multinationals. On top, thanks to their closer geographically presence they are able to physically pass by your facility to identify and resolve the problems as fast as possible. When it comes to repairing plasma system issues, extra prudence is advised. These are extremely complex machines which generate & channel a tremendous amount of power. We strongly recommend you always contact a leading CNC machine manufacturer, who will be able to connect with plasma system developers such as Hypertherm to discuss and resolve the issue.

Service support from a CNC Plasma cutting machine manufacturer

Preventative Maintenance Service

Having to repair your plasma cutter is a stressful and costly thing. Your business is interrupted, costs are accumulating by the hour, and if you might need to pay extra for urgent delivery of spare parts or technician help. That is why it is absolutely crucial you have a proper maintenance process in place to avoid any issues in the first place. However, seeing the complexity of machine maintenance, many companies also rely on machine producers to service their machine. This preventative maintenance service can range from 1 to 4 times a year, depending on your specific application and the number of cutting hours your machine has to perform. Outsourcing the maintenance of your plasma cutting machine offers many advantages.

You will have ease of mind knowing your machine is getting the best possible care by expert technicians,
You don’t need to train your own people as thoroughly.
if the machine manufacturer works with its own technicians he will have immediate access to any replacement parts if needed.

Like this you ensure your production remains interrupted and running at max capacity.

Preventative maintenance service support

Conclusion

If your plasma cutting machine is down you want it repaired as soon as possible. If you or your own operators are leading the repair, make sure they are properly trained. For more complex repairs, or in case of doubt, refer to an expert technician, preferably a plasma machine manufacturer. In case you’re looking for such expert help or have any questions regarding repair of your plasma cutting machine, the Esprit team is happy to help. We are able to repair most plasma cutting machine, regardless of the producer. Moving forward, also remember that it will always be better to prevent than to cure. A preventative maintenance routine could avoid these costly situations in the future.