Know Every What and How of Plasma Cutters

Do you want to buy a plasma cutter? There are various things you must keep in mind before making the final decision. Even if you already have one, there are many questions you might have – which air compressor to use, how to use consumables etc. Don’t fret no more, we answer all the frequently asked questions in this article. Whether you are a hobbyist or a professional, this guide will help you improve your plasma cutting process.

Frequently Answered Questions

1/ What is plasma cutting?

Plasma cutting is a process of cutting electrically conductive metals with the help of hot plasma. Plasma is the fourth state of matter; air, liquid and gas being the other three. This plasma is sprayed with the help of an accelerated jet which focuses all the flow in a uniform and narrow area with the help of a nozzle. The plasma that cuts the metal usually has a temperature of over 20,000°C range. Plasma cutting is widely used for industrial and small-level projects. Plasma cutting is considered better than oxyfuel for cutting materials up to a thickness of 2”.

2/ What is CNC?

CNC is an abbreviation for Computer Numerically Controlled. Basically, CNC is automated cutting as opposed to handheld cutting. In CNC cutting, the torch head is operated by automated CNC systems for precision cuts. This cutting process is widely used in industries for large scale purposes. CNC systems are better suited for decorative work in commercial industries to design signs, banners or wall art. Handheld systems are best suited for small level projects and for hobbyists where small errors in design can be neglected.

3/ What is the difference between maximum cut and severance thickness?

Maximum or clean cut refers to the cut made with fast speed and no slag or dross. Clean cut is the cut you’ll be able to make without any hassle. On the other hand, severance cut is the cut you’ll make when you keep your hand steady for a longer time period. Severance cut can leave bevel or slag after the cut. This leads to low productivity as one has to clean the material manually or with a grinder. Hence, you must determine how deep you want to cut before buying a plasma cutter. For bigger cuts, more expensive and industry oriented plasma cutters are recommended.

4/ What type of materials does plasma cutters cut?

Plasma cutters cut electrically conductive materials. Most common materials cut by plasma cutters include mild steel, stainless steel, aluminium, copper and brass. Ideally, plasma cutters are best suited for non-ferrous materials with a thickness of less than one inch. One can also cut alloys or cast metal and other materials as indicated by the manufacturer. Different materials give different cuts with the plasma cutting process. Mild steel and aluminium give the fastest and cleanest cuts.

5/ What is duty cycle?

Duty cycle is the time duration during which a machine stays busy or remains in active state. For example, a plasma cutter with 60% duty cycle can cut for 6 minutes out of 10. It remains idle for the rest 4 minutes and starts working again for 6. Duty cycle is important as it affects productivity. If you want the plasma cutter to work longer for continuous time, choose one with a higher duty cycle. If you want to work on and off again, a lower duty cycle might be more suitable for your needs.

6/ What are the things I must consider before buying a plasma cutter?

There are many factors that determine which plasma cutter will best suit your needs. These factors include cut thickness, duty cycle, budget, portability requirements, power, consumable life, automation etc. Determine how thick you will be cutting metals most of the time. Duty cycle will help you work productively. Budget is extremely important consideration to buy a quality and value-for-money plasma cutter. Longer consumable life will ensure you don’t have to hunt for new consumables every other week. Automation means that you need to determine whether you’ll be operating the cutter by hand or using it with CNC machine.

7/ What is the difference between manual and automated plasma cutter?

Manual plasma cutting refers to cutting conductive materials with handheld torch while automated plasma cutting refers to cutting materials with CNC machines. CNC machines help producing finer, more decorative and cleaner cuts than those achievable manual cutting. CNC machines are best suited for industrial purposes where the design has zero margin of error.

CNC machines have become very advanced with multiple axis cutting which can give even more complex cuts. On the other hand, manual cutting is best suited for DIY (Do It Yourself) or small level projects.

8/ Which plasma cutter is the best for DIY projects?

There are many plasma cutters available at affordable costs but have different specifications or attributes. Our series of frequently asked questions consist of all the things you must consider before buying a plasma cutter. In our analysis of plasma cutters, we have found that the Lotos LT5000D 50A Air Inverter is the best one for hobbyists. This beast is compact but a quality package and provides features such as tig and stick welding along with cutting. The best part is that it is powerful enough for industrial purposes too. Hence, you can expect the best-in-class performance with this machine. For a comprehensive review of all plasma cutters, refer to our plasma cutter guide.

9/ Which plasma cutter is the best in an industrial setting?

The Hypertherm Powermax 45 is the best unit for industrial settings. It comes with the reliability of the brand and good customer service. The Powermax 45 gives the fastest and cleanest cuts possible in the market. It has a dual angle torch which makes the tip of the torch more durable. One great asset of Powermax 4 5 is that you don’t need to prepare edges or grind before starting the cutting process. Just push the button and zoom through the material.

The unit has a severance thickness of 1” and gives butter smooth cuts even at ½”. It has a patented drag cutting technology makes it especially lucrative for beginners. This technology increases ease of use. For more information on industrial plasma cutters, browse through our plasma cutter guide. To know how to use plasma cutter, scroll down below in this frequently asked questions series to get link to free training.

10/ What is pilot arc?

Pilot arc is an advanced technology for the torch where there is no contact between the torch and the material to be cut. The torch cuts the material from a distance, hence making the torch more durable. The best part is that it easily works on rusty or dirty metals without having the need to clean them first. It also produces finer cuts than a normal torch. Pilot arc is an integral feature of many LOTOS products. It not only gives cleaner cuts, but increases the life of nozzles and electrodes.  For more information on pilot arc and related products, browse through our plasma cutting guide. Refer this frequently asked question series for other questions you may have.

11/ What steps should I take to extend consumable life?

Make sure the plasma cutter has sufficient cooling system. If the cooling system isn’t good enough, the electrodes, nozzle and other consumables will wear out a lot faster.

Another thing to check is that the plasma gas flow should be high enough. High flow ensures there is always a thin boundary of cool gas that prevents the nozzle from melting.

Current setting can also destroy your consumables. If the setting is automated, well and good. But if it is manual, make sure it doesn’t produce excessive current flow that can damage the nozzle and electrodes within a matter of seconds.

Not only you must choose an effective cooling system, you must also choose the right coolant for your plasma cutter. Hit google and find the coolant with the best reviews.

If you’re using an automated cutting mechanism via a CNC machine, you need to learn how to adjust all the control settings. Kerf width, amperage, pierce height etc. can make or break your plasma cutter. So be extra cautious with CNC machines.

Make sure you keep this things in mind or you’ll end up hunting for consumables every other week.

12/ What type of air compressor should I use?

The first thing to check is that the air should be dry and clean. Otherwise you’ll pre-condition the machine to wear out quickly and give ineffective cuts. There are other things you must determine before choosing a compressor. For example, how much pressure will be required, the required CFM usage, whether the machine will be portable and receiver tank size. Choosing an air compressor requires a detailed understanding of these aspects.

A simple strategy for gauging the quality of the product is to check the time period for which the company has been in business. Gauge their reputation using online forums and other means. Inspect about their customer service, the accessories and availability, their product lines etc. Do your homework!

For detailed technical instructions on how to choose an air compressor, refer this link by a top brand.

http://www.jennycompressor.com/howtochoose.html

13/ Is plasma cutting more effective than oxyfuel?

In one word – yes and no. Plasma cutters produce concentrated hot plasma flow to cut precisely. Oxyfuel is not suitable for non-ferrous materials, hence only plasma cutters do the required job. Plasma cutters don’t work effectively when cutting thicker materials. For materials having thickness less than or equal to 2 inches, plasma cutters are more suitable than oxy-fuel. Some cutters have both oxyfuel and plasma torches to cut materials with a large thickness range. Such cutters are only used in industrial settings. For hobbyists or DIY projects, plasma cutters are unquestionably the best in the market.

14/ Which type of table is better – water or downdraft?

Water tables are less expensive than downdraft tables and have different attributes which may or may not appeal to you. Water tables absorb all the noise and smoke that is produced by plasma cutters. But the dirt gets mixed with water which can lead to poor cuts and torch damage. Downdraft tables have many filters which need to be replaced from time to time. But they are more reliable and produce cleaner cuts. Hence, the latter is preferred by most people.

15/ Can I cut materials other than aluminium and steel?

You must refer to the cutting chart that is provided by the manufacturer. Other than aluminium and carbon or mild steel, you can also cut stainless steel, copper, brass, , titanium and INCONEL. If you’re cutting a material not listed here, always contact the manufacturer for the right information. Good companies provide quality customer service which will come handy in this situation.

16/ How can I learn plasma cutting if I am a beginner?

If you go through this frequently asked question series, you’ll find the best plasma cutter for beginners or hobbyists. Most plasma cutters have no pre-requisite as such and the information is either available online or in the user guide. Still, if you want to learn more there is quality training available right on your computer screen. For learning extensively about the plasma cutting process, learn through this online course offered by Hypertherm brand, the best in the business. http://www.hypertherm.com/en/Training_and_education/Resources_for_educators/hci.jsp

Conclusion

After you get acquainted with the basic terms involved in plasma cutting, like duty cycle, thickness, amperage etc., you must learn about more complex things. Learn how to choose the right air compressor as it is one aspect you can’t ignore even if you have the best plasma cutter in the world. Learn how to make consumables more durable. Determine your needs such as thickness, portability etc. and choose a product that fits your needs. Always remember that investing more money doesn’t necessarily mean you’ll get better quality. When it comes to plasma cutters, knowledge is power!