High Performance Used CNC Plasma Cutters

A  plasma cutter is a machine used to cut through electrically conductive materials, like steel and aluminium. Using a high-temperature plasma arc, results are fast and accurate, making it ideal for commercial use. They're widely used in industries like manufacturing, automotive repair, construction, and art. You can get single phase models for home or hobby use, suitable for cutting thin metal sheet. Or 3 phase input, industrial machines, capable of cutting sheet metal 40mm thick and above! Mechanised, production cutting is also an added benefit of plasma cutting. Using a CNC unit and cutting table, sheet steel and aluminium cutting is both efficient and easy!

A plasma cutter works by using an electric arc to ionise a gas (like air, nitrogen, or argon), turning it into plasma. The plasma, reaching temperatures up to 30,000°F or 16,500°C, is then forced through a narrow nozzle. This creates a focused, high-speed jet to produce the cut via means of a plasma torch. The plasma jet melts the metal, and the force of the jet blows the molten material (also known as slag) away, leaving a clean cut.

A plasma cutter is used for cutting conductive metals, and make light work of materials like aluminium, mild, and stainless steels. As well as brass, copper, and some other sheet metals. Although suitable for hobby use, plasma cutters are one of the more expensive tools on the market for sheet metal cutting. So are more suitable for industrial uses like automotive manufacturing/repairs, shipbuilding, and general fabrication.

Yes, a plasma cutter can cut aluminium. They are ideal for aluminium fabrication applications like cutting parts or panels in the automotive idnustry. As well as aircraft components and parts for the marine industry, like boat hulls and interior fittings. Other cutting methods like laser cutting and waterjet cutting are also used for aluminum cutting in specific applications. The choice of cutting method depends on factors such as material thickness, required precision, and the overall project requirements.

Yes, plasma cutters are commonly used for cutting stainless steel. Stainless steel is widely used in various industries, including construction, manufacturing, and food processing, and plasma cutting is a common method for shaping and fabricating stainless steel components. Plasma cutting is the ideal solution for cutting corrosion-resistant components in industrial machinery, and architectural features in construction. As well as food and beverage machinery like commercial kitchen equipment and storage tanks.

Like with other materials, it's important to follow the recommended parameters, use appropriate consumables, and ensure proper maintenance of the plasma cutter for optimal cutting performance.

Choosing the right plasma cutter depends on several factors related to your specific needs, budget, and materials. Here’s a guide to help you make an informed decision:

1. Material Type and Thickness

• Cutting Material: Determine the types of materials you’ll be cutting (e.g. steel, aluminium). Most plasma cutters handle a variety of conductive metals, but some are better suited for specific materials.
• Thickness:
• Check the maximum cutting thickness the plasma cutter can handle.
• Look for three ratings:
• Cutting Thickness (for clean cuts)
• Severance Thickness (for rougher cuts at the greatest capacity)
• Piercing Thickness (if starting cuts in the middle of the material).
• Choose a machine that exceeds your typical material thickness needs for better efficiency and clean results.

2. Power Supply

• Input Voltage:
• 120V: Suitable for light-duty work on thinner materials.
• 240V/415V: Ideal for industrial or heavy-duty cutting.
• Dual Voltage (120V/240V): Offers flexibility to work with both.
• Amperage Range: Higher amperage provides better performance on thicker materials. Consider plasma cutters with adjustable amperage for versatility.

3. Cutting Speed

• Look at the Inches Per Minute (IPM) rating to compare cutting speeds at various material thicknesses.
• Faster cutting speeds save time, especially for production work.

4. Air Supply

• Plasma cutters need a gas supply (e.g., air, nitrogen). Options include:
• Built-in Air Compressors: Convenient for portability.
• External Air Compressors: Offers more power but requires a separate unit. Ensure compatibility with the plasma cutter.

5. Duty Cycle

• The duty cycle indicates how long the machine can run continuously before needing to cool down. Expressed as a percentage, the higher the duty cycle, the greater capacity the machine has. Read more about duty cycle here.
• High Duty Cycle: Ideal for industrial and frequent use.
• Low Duty Cycle: Enough for occasional or hobbyist use.

6. Portability

• Weight and Size: Choose a lightweight, compact unit if you need portability for taking to site.
• Handle and Case: Look for ergonomic designs and protective cases for ease of transport. Keep in mind the age-old saying, "Buy cheap, buy twice!"

7. Pilot Arc or Non-Pilot Arc

• Pilot Arc: Allows you to cut without direct contact with the material, making it ideal for rusty, painted, or uneven surfaces.
• Non-Pilot Arc: Requires direct contact and is best suited for clean surfaces.

8. CNC Compatibility

• If you plan to automate cutting, choose a plasma cutter that is compatible with CNC systems. This includes models like the Hypertherm Powermax range for light industrial use. Or for heavy duty fabrication, the HPR range from Hypertherm offers optimum performance for production cutting.

9. After Sales Support

• Opt for a reputable supplier with good customer reviews and technical support.
• Ensure replacement parts like electrodes, nozzles, and consumables are available. Try to keep some on hand to avoid unnecessary down-time.

10. Budget

• Prices range hugely, and depend on features, power, and quality. Set a budget based on your use case:
• Hobbyist/Light Use: £500 - £2000
• Professional/Industrial Use: £1500 – £30,000
• Buying a used machine can open up your options, affording you a machine that might not be in your budget otherwise. Take a look at our current stock above, offered with warranty and lifetime aftersales support.

11. Safety Features

• Look for features like overheat protection, insulated handles, and voltage safety systems.

Next Steps

1. List Your Needs: Write down the materials you'll be cutting, thicknesses, and usage.
2. Research Models: Compare plasma cutters from trusted brands like Hypertherm, Miller, Lincoln, or ESAB).
3. Seek Advice: If possible, consult experienced users for feedback or have a look at some forums online. Suppliers should always give you unbiased advice too! You might also get to demo the machine, but bear in mind it might not be in the context you will be using it.
4. Long-Term Costs: Factor in consumables, maintenance, and energy costs.

By assessing these factors, you can select a plasma cutter that meets your needs, and ensures efficient, clean cuts for your projects.

When choosing a plasma cutter for CNC, ensure that the model you select is compatible with your plasma table and control system. Additionally, consider the capabilities of the plasma cutter, these will need to meet, or possibly exceed your needs for optimum performance. Important factors also include level of support, availability of consumables, and the reputation of the manufacturer for providing reliable equipment. The following brands have been industry leaders for many years:

• Hypertherm
• ESAB
• Kjellberg
• Lincoln Electric

It's important to thoroughly research and, if possible, consult with your plasma table manufacturer, or experienced users, to ensure that the plasma cutter meets the needs of your application.

Plasma cutting, like any other industrial or metalworking process, can be potentially dangerous if not performed with proper safety precautions. Risks include electric shocks, arc flash and UV radiation, noise and fumes, and fire hazard. Taking appropriate measures to mitigate these risks, like wearing appropriate PPE, using fume extraction solutions and keeping equipment properly maintained will ensure the safety of operators and the workplace.

A plasma cutter needs air (or another gas) as part of its cutting process to create and sustain the plasma arc. When the gas flows through the plasma cutter, it combines with a high-voltage electrical arc. It's this reaction that creates the plasma jet you see at the end of the torch. It also acts to remove molten material (dross) from the cut, as well as cooling the torch, thus helping to extend consumable life.

There are alternatives to using compressed air, including nitrogen, oxygen, and argon-hydrogen mixture. In some of these applications, one of these alternatives might be required. However, compressed air is popular as it's readily-available, inexpensive, and is effective for the majority of plasma cutting applications.

No, you can't use a plasma cutter without gas, they need gas to produce the plasma arc. The gas that you will need depends on the material and the thickness. The most common plasma gases are compressed air, high purity air, oxygen and nitrogen. Read more in our article The Best Gases to Use for Plasma Cutting.

If your plasma cutter keeps stopping during operation, here are some troubleshooting tips to check, and hopefully rectify the issue.

• Overheating - which indicates the machine has reached the limit of it's duty cycle and may need to cool off.
• Air supply issues - ensure that the flow rate and pressure are within the range specified by the manufacturer. You may also need ot check for leaks in hoses, fittings, and the torch.
• Electrical issues - make sure the plasma cutter is receiving the right voltage, and that the input power supply is stable. Check connections, cables, plugs and extension cables for damage/wear and tear.
• Consumable wear - inspect all consumables (nozzles, electrodes etc.) for signs of significant wear or damage. Replace as necessary.
• Material thickness - make sure you are not trying to cut material that is out of capacity for the plasma cutter you're using.
• Gas supply - check that the gas supply is connected properly, and that the pressure is as recommended by the manufacturer.
• Software and controls - if you have a CNC plasma cutting bed, you may have an issue with the software or control unit. Check for any error messages or software updates, and ensure all cabling is connected properly.
• Machine faults or malfunctions - if you've gone through the above steps and the issue isn't rectified, there might be an issue with the machine itself. In which case you may need to send it back to the manufacturer for repair, or seek the help of a qualified service technician.

A CNC plasma cutter, or CNC plasma cutting table, is an automated method for plasma cutting sheet metal. The plasma torch is mounted onto a carriageway above a cutting bed, and controlled by a CNC (Computer Numerical Control) unit. It is an extremely beneficial method for production plasma cutting applications, as the CNC unit can store many programmes, as well as provide maintenance and performance insights to improve efficiency.

A CNC plasma cutter works by a Computer Numerical Control (CNC) unit controlling the cutting operations. The plasma cutting table operator either inputs the parameters on the CNC unit for the current job, or chooses from a pre-stored programme, and the control unit feeds this information to the carriageway and plasma torch. It is a highly efficient process, as not only does the CNC unit store multiple programmes and jobs, but they also monitor performance and maintenance, reducing downtime and maximising productivity for plasma cutting processes.

There are some major differences when comparing CNC plasma cutting with  fibre laser cutting. Firstly, a CNC plasma table can cut up to 160mm, but best results and cut quality are usually seen around 25-40mm (1-1.5") with HD plasma. Laser however, is only suitable for thin sheet of up to 25mm.
Laser offers better accuracy than HD plasma, with an impressive 0.05mm, and CNC plasma cut parts being 0.5 - 2.2mm. Cutting speeds when fibre laser cutting thin sheet <10mm are also much faster compared to high definition plasma cutting, however thicker than 10mm, and CNC plasma cutting offers superior cut speeds.
Finally, there's the cost. A laser cutter is a much more expensive initial purchase compared to a CNC plasma table. If you're main cutting application is production cutting thin sheet metal, you can expect to break even after approx. 5 years. If you require more versatility with material and cut thickness range, an HD plasma cutter could be far more beneficial for you.

ESAB offer a wide range of plasma cutting machines. Manufacutred under their Thermal Dynamcis brand, there are models available for both manual and mechanised plasma cutting.

Current portable models for hand plasma include the popular Cutmaster series, inverter based power sources with high duty cycles, offering superior cutting performance on material thicknesses from 10mm, up to 50mm. Or the HandyPlasma, single phase machine; a simple and portable power source ideal for light sheet metal cutting. For heavy duty manual plasma cutting, their PAK 200 and 300 models are designed to replace the industry-renowned PAK45 by Thermal Dynamics. Made for demanding work like in foundries or heavy construction, these workhorses offer plasma cutting of thicknesses up to 100mm, an unrivalled benefit in the current marketplace. 

Older machines include the ESP, PCM and Powercut, with some still being serviced and parts available.

Mechanised options for CNC plasma cutting include the current iSeries; an automated plasma cutting solution designed with profitability in mind for demanding plasma cutting applications, and the M2 200i; offering cutting of thicknesses up to 25mm with a high duty cycle for production sheet metal fabrication. The Cutmaster A series is the ideal machine for smaller, compact tables used for light to medium duty plasma cutting, and is the sister machine to the manual version of the Cutmaster. 

We would also recommend their older Plasmarc CNC plasma cutting power source, as well as the Precision series, often found on used CNC plasma cutters.

Some common troubleshooting tips for an ESAB plasma cutter include:

No arc or weak arc:

• Check the power supply and ensure all connections are ok, the voltage is correct, and there are no blown fuses. 
• Make sure there are no issues with the torch or consumables, worn electrodes, nozzles and swirl rings can all cause arc failure; replace if needed.
• Check the air supply - low air pressure or moisture in the air can also cause arc failure. Ensure the pressure is correct (refer to the machine manual), and use a clean, dry air supply.

Arc starts but won't cut:

• Ensure the ground clamp is properly connected, and material surface is free of contamination like rust or paint.
• Check the cutting speed, as moving too fast can prevent full material penetration.
• Make sure the amp setting is correct for the material thickness and increase amperage if necessary (refer to machine manual for recommended settings).

Poor cut quality and excessive dross or slag:

• Is the torch height correct? Too high and you won't achieve sufficient penetration, too low and you'll get excessive dross, so adjust as necessary.
• Check the air pressure, as insufficient air pressure can result in irregular cuts. Increase to be in line with the specs.
• Check the consumables, as excessive wear without replacing will lead to inconsistent cutting.

Common ESAB error codes:

Refer to the machine manual for any specific error codes and how to rectify potential issues, but some of the more common error codes include - 

• E02 - low air pressure
• E03 - over-temperature shutdown
• E05 - torch consumable not detected

If you have any specific queries regarding the operation of your ESAB plasma cutter, give the team a call or contact us here with your query, and someone will be in touch!