Archive for the ‘Plasma Cutters’ Category

The Plasma Cutting Process : PAC

Monday, October 3rd, 2011

Plasma Arc Cutting (PAC) is probably one of the single most coveted items in a well equipped shop. Almost all commercial shops are equipped with Oxy-fuel for cutting. In fact, I can’t think of any reason a commercial shop would not have a Oxy-Acetylene rig. But up until the last 10 years, many established shops did not have a plasma cutter. A few still don’t. As technology has improved, and prices have gone down and availability has gone up, more and more shops and even hobbyists are making the plasma plunge.

What makes plasma so desirable? It would be difficult to pinpoint any one feature. Plasma cutters are capable of making extremely clean and accurate in any metal, something that cannot be done with Oxy-Acetylene torches. Speed is another factor, with plasma having an edge over Oxy-Acetylene when trying to achieve similar cut quality. Low temperature input also reduces metal distortion while cutting. A major deciding factor for most is the relatively low skill required to operate one. Almost anyone can turn out competent cuts within a short amount of time with just a little practice. Most plasma cutters are easily taken right to the site to work. There’s no dangerous gases to work with. There’s no large bottles to carry around or fill. Most plasma cutters use air compressors which are already found in many shops. Air hoses can be run quite a long ways to the unit giving a lot more portability around the shop with a reduced foot print. Some plasma cutters even have the compressor built in and will operate on 120 volts, allowing it to be used almost anywhere in or out of the shop.

There are some drawbacks to plasma though. While plasma may give Oxy-Fuel a run for its money on performance cutting, it cannot be used in situations where it is necessary to heat metal. Nor can it weld or braze. Plasma can only be used to cut or gouge any metal. Oxy/Acetyelene will weld, cut, braze and heat…though it is limited mostly to steel on cutting. The initial purchase of a plasma system is much higher as well, especially if an air compressor is needed. Consumables should always be kept handy as this is a wear item that is constantly needed. Also, electricity is needed and may be a limiting factor in remote locations. Oxy-Fuel rigs have no such requirements. Torch tips for Oxy-Fuel last much longer for sure and rarely need replacing.

Carefully evaluate your needs and capabilities before purchasing a plasma cutter. It is not a good fit for everyone. It is not a substitute for a good Oxy-Fuel rig because of its limitations. But if you do feel it’s a good fit for you, Everlast offers a full range of plasma cutters from 50 to 100 amps, with cutting capacities up to nearly 2 inches. Well priced from $700 dollars, there’s probably a unit that will fit your needs.

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Need for Water Shroud in Plasma Cutters

Tuesday, May 10th, 2011

The plasma can be made to function with a water shroud or in an alternative case by submerging the work piece for some 50 to 75mm below the surface of the water. Either ways, water is used to keep the condition or temperature of the process under control.

Unlike in the usual plasma cutting methods, we can find that the water takes the role of being the barriers. The advantage of Water Shroud in plasma cutters is that it reduces fumes, decreases noise levels to a great extent and improves the life of the nozzle.

In a usual method the noise levels were noted to be at high current levels of 115dB. But for the conventional plasma cutting machine we can note that the water shroud played a vital role in reducing the noise level to about 96dB.

Seeing that the water shroud will not add to the quantity of constriction, we can note that the squareness of the cut edge as well as the cutting speed is improved to a great extent.

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What is High tolerance plasma?

Monday, May 9th, 2011

Unlike in normal plasma cutting method in which there is no sharp or squireness in the edges we can get the right result that we need in this method. Getting an improved cut quality is no more difficult as we have High Tolerance Plasma Arc cutting, that are also known as HTPAC systems. These High Tolerance Plasma Arc cutting are obtainable with an extremely constricted plasma flow.

To be precise we can say that High Tolerance Plasma Arc cutting method is an automatic technique which requires accuracy, speedy tackle. We can get great results with thicker sheets starting from a minimal thickness of about 6mm.

Apart from this the cutting speed of these High Tolerance Plasma Arc cutting method is usually lesser than the usual plasma processes and can be calculated to be just about 60 to 80% the speed of a laser cutting method but still give a great cut at the end. The Cut quality lies between a usual plasma arc and the laser beam with Narrow kerf width. As the heat affected zone is very small, there is less or very minimal distortion.

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Water injection in the Plasma Arc Cutting Process

Friday, May 6th, 2011

As we all know water is used as a coolant in many industrial methods that involves high temperature for the process. Same ways water injection in the plasma arc cutting process also has a specific use. Water is injected through the injector into the plasma arc.

The plasma arc is generally got when Nitrogen is used as plasma gas in most of the plasma cutting machines. When the water is introduced to the plasma arc it induces a high degree of constriction. We can note that the temperature shoots up considerably to 30,000°C and above in this particular process.

If you compare the above process advantages with conventional plasma you can notice that there is a substantial Improvement in cut quality as well as squareness of cut. Apart from the improvement in cut quality we can also find an increase in cutting speed, less noticeable risk of double arching as well as decrease in nozzle erosion.

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Powers Source of the Plasma Arc Cutting Process

Thursday, May 5th, 2011

Plasma arc cutting process is one of the most efficient methods available to ensure sharp and perfect cut on any metal sheet of any desired thickness. The power required for such perfect cut is high and is attained by regulating that amount of plasma flow which is required for each metal sheet.

The power source for the Plasma Arc Cutting Process should contain a relaxed characteristic as well as a high voltage. Even though the operating voltage for sustaining the plasma used for the cutting process is on average 50 to 60V, the open circuit voltage that is required to kick off the arc is noted to be up to 400V DC.

On start, the first arc is created inside the cavity of the torch which is between the electrodes along with the nozzle.  When the cutting is to be performed the arc should be transferred to the work piece and is hence called as the transferred arc mode.

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Cut Quality Of The Plasma Arc Cutting Process

Wednesday, May 4th, 2011

Plasma cutting is a process that requires very less effort from the person who handles the machine. Many times the machines are seen to give out the accurate cut that was planned for and there is a chance of slight variations or issues only if the machine is not maintained well. If you need a clean cut without any clogging or variations, plasma arc cutting process is the best to choose.

The quality and the output of a plasma arc cutting process are well known. A technician who has used different types of welding and cutting machines can easily find out the difference and advantages of using these plasma cutting machines.

We can compare the cut quality of these machines to that of the oxy-fuel process but as plasma cutters use melting method to cut the metal sheet we can find that it leads to top edge rounding, reduced edge squareness otherwise called as a bevel on the cut edge at the result. Off late we are able to find different torches that are specifically designed to overcome arc constriction and give way for extra uniform heating at the top as well as the bottom of the cut.

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An insight into CNC plasma cutters

Friday, April 8th, 2011

Plasma is a state of matter found only at high temperatures. Plasma cutters are welding equipment which uses this state of matter to cut electrically conductive materials very quickly and very precisely. CNC plasma cutters have revolutionized the field of welding in several ways. They used specialized software that controls and directs the plasma torch. It incorporates speed, accuracy, efficiency and repeatability for the plasma torch.

The plasma can reach temperatures as high as 30,000 Fahrenheit and very easily cuts through 2 inches of metal. CNC plasma cutters are even more efficient along with the abilities of plasma mainly because of the fact that they are driven by computer numerically driven controlled software. CAD/CAM is integral part of each CNC machine. CNC assures precise handling of the machine and exacts the distance between the plasma nozzle and metal sheet. It also includes nesting capabilities which makes the plasma cutter even more efficient.

Plasma cutters come in different shapes and sizes. The only thing that differentiates among them is their construction and the components. High quality units have solid, heavy-duty, fully welded unitized construction. They can be quite expensive. Lesser expensive equipment is less stable and thus leads to lesser accurate plasma cutting. All together it will be a less efficient machine.

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What is plasma?

Tuesday, March 29th, 2011

We must have heard about stuffs working with plasma but, what is this plasma exactly? Plasma is the 4th state of matter. It is produced by passing inert gas around an electrical discharge. The gas is blown out at high speeds through the electrical arc and this gas is superheated to the plasma state.

There are many methods that most welding machines that employ plasma use to create the plasma. The most common use of plasma is in plasma metal cutters. Here the plasma is concentrated with the help of a nozzle onto a point that will help to cut through the metal. This metal is much more efficient than the conventional welding methods.

Also this method can be used to cut through layers of metal with ease. Most metal cutters from all over the world today are switching to plasma cutting methods because of its efficiency and its reliability to produce neat cuts when compared to the traditional cutting methods. There are portable plasma cutting methods that are available for the similar purposes today. Plasma cutters are one of the most efficient as well as quick methods to cut metal sheets of thick or thin breadth.

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Tips for Field Repair

Tuesday, March 22nd, 2011

It is important to have the best of quality equipments and immense knowledge in welding along with at most concentration when we are working with welding applications. Selecting proper engine driven welding generators, plasma cutters and other repair tools helps you to prevent downtime by fixing repair works right at the first time.

Equipment repair is adds up to your vows more compared to the complications you encounter while you weld. Every minute your machine turns down is a minute of lost time and minutes turn to hours when servicing those machines. Immense knowledge and experience in welding enables you to estimate the right kind of tools you always would need for the job and helps you to reduce downtime drastically and finish off the work quickly. At the end of the day your intelligence and quality of equipments predicts the outcome whether it’s a profitable one or not.

In order to finish off the field repair there are five basic steps you need to follow;

1.    Cut out broken steel with Oxy-fuel, Plasma or Carbon arc Gouging. This is the initial step         when  it comes to field repair. Most contractors have oxy fuel equipments for cutting, brazing, soldering, and preheating welding surfaces
2.    Match and cut replacement steel. Match your equipments based upon their strengths and  replace them. Cut your steel to its required size.
3.    Preheat to eliminate cracking. Fill the replacement steel to find irregularities and check its fitting. After achieving proper fit, preheat the surface with oxy-fuel equipment.
4.    Electrode Selection and Welding Technique. Mostly stick welding technique is preferred.
5.    Select your welding system. This factor depends upon the electrodes you have chosen in the previous step.

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Plasma cutting

Tuesday, March 8th, 2011

Plasma cutting has become a popular metal cutting process. It involves the use of a plasma torch to cut through steel and other materials of different thickness. The torches works on the principal of blowing out compressed air out of the torch nozzle that would create an electrical arc that would help to cut through material of different thickness. Today the plasma cutting torches have become portable that can be carried over the shoulder.

There are many features that help to meet routine shop challenges easily. The plasma torches today come with an adjustable post flow cooling technology that would help to make the cutting smooth. Also many of these torches carry a special track torch operation. You should however consider a heavy duty plasma torch if you are a considering a heavy industrial type project.

The size and bulk of the machine would compensate for the performance that it would provide on the project. It works well under pressure and at most times will go beyond the call of duty if you are pushing it. Most of these machines are optimized so that they get the job done without consuming too much power. These would be ideal for a fabrication shop or general automotive repairs.

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