Choosing the right plasma cutter: You’re Plasma Cutter Selection Guide
Deciding on which Longevity Plasma Cutter will work best for you can be a tough choice to make considering that selecting a plasma cutter is a major investment. Fortunately, the Longevity Plasma Cutting Sales team is very knowledgeable and can assist you in the right direction. First, we would like to go over the plasma cutter basics and describe some important plasma cutter information.
When deciding what Longevity Plasma Cutter is best for you, there are several questions and key points to consider:
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How thick is the metal you most often cut?
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What is the maximum thickness you might cut?
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What kind of metal are you cutting?
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How fast do you want to cut and what is a cut rating?
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What operating voltage will work best for you?
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Duty Cycle (DC)
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Pilot Arc vs. High Frequency Plasma Cutters
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Will you need to make them work with CNC tables?
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Knowing the right Amperage
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Which technology MOSFETs vs IGBTs
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Consumables and Operating Cost
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How long will plasma cutter consumables last?
First, we will take a look at how thick of metal you most often cut, how fast you wish to cut the metal, what types of metals will you be cutting, and what operating voltage will be required in order to operate the plasma cutter. Below, we have included a very informative chart of all Longevity Plasma Cutters showing their cutting capabilities, features, and typical applications.
For example, We will start with the Longevity ForceCut™ LP-50D Plasma Cutter. As you can see this unit will cut up to ¾” thick material at 50amps with a 60% duty cycle. Choosing this plasma cutter will be ideal to individuals who are looking for a strong plasma cutter that will cut up to ¾” and is also versatile with the input voltage. The Longevity ForceCut™ LP-50D is unique because it will operate on either 110v or 220v. This is a very positive feature because the plasma cutter is a feather only weighing 23lbs and is extremely portable being able to operate on dual voltages. It is very important to understand the most common thickness you will be cutting and the maximum thickness you will be cutting. If you are choosing a plasma cutter that is capable of ¾” cutting, but your job requires you to most commonly cut ¾”, we suggest upgrading to a more powerful cutter. The rule of thumb is you want to have a plasma cutter that you can operate at 75% capacity and still get all you cutting requirement.
Generally, most hobbyist and auto body shop workers choose the Longevity ForceCut™ LP-50D because of its versatility, size, and power!
What type of material will you be cutting?
If you are in need of a plasma cutter that will mainly be cutting aluminum, which is one of the harder metals to cut, you will need to get a plasma cutter that is more powerful. Fortunately, Longevity Plasma Cutters are affordable and you can get a powerful cutter for ¼ of the price that a leading brand charges.
When selecting a plasma cutter based of the metal you will be cutting, it is always best to get a model that has a high cut rating on the aluminum side. Aluminum is very tuff metal to pierce, gauge or penetrate. Longevity recommends you consider a 60-80amp plasma cutter because they are more industrial and powerful, thus your unit will not struggle cutting aluminum or other painfully hard to cut metals.
Cutting Speed and Cut Rating:
The more powerful the plasma cutter, the faster it will cut through metal at any given size. It is very important to consider the type of Longevity Plasma Cutter will be sufficient enough to save you time while cutting. The Longevity ForceCut™ LP-50D cut rated specifications are impressive for the size and the price of this powerful plasma cutter:
3" Per minute @ 3/4" Steel (Severance Cut)
7" Per minute @ 1/2" Thick Stee
17" Per minute @ 3/8" Mild Steel
You will need to review each plasma cutter to see the speed they are able to cut. If you are not in a hurry, then you may be able to get a less expensive cutter that will give you a fine quality cut with a bit of a longer duration. Remember, the cutting speed of each plasma cutter is also affected by the material being cut.
Determining the Cut Rating:
Rated Cut- The thickness of metal an operator can manually cut mild steel at a rate of 10 inches per minute (IPM). 10 IPM is the arbitrary speed chosen to be the minimum at which an operator can achieve a smooth cut at the best quality. For example, the Longevity ForceCut LP-60D has a rated cut of 1" thick steel.
Quality Cut- Is rated at cutting thicker material at a slower speed achieving a cleaner looking cut. For example, the Longevity ForceCut LP-80 has a quality cut of 1½” at a speed of 7” per minute, which is less than the rated cut standard of 10” per minute
Severance Cut (Aka Sever Cut)- The cutting speeds for this cut are much slower as the operator is pushing the plasma cutter to its max potential cutting the thickest material possible. The speed of the cut does increase as the thickness of the metal being cut reduces – thus it is important to have a plasma cutter with a large duty cycle for long cutting time.
What Operating Voltage Will Work Best for You?
Getting back to operating voltage, Longevity offers several models that are capable of 110v and 220v power sources. Please remember, that when you are using your Longevity Plasma Cutter at 110v, you are only using the machine to about half its full capability. With that said, Longevity plasma cutters are best used at the 220v power source, but depending on the model, they will cut up to 3/8” with an 110v power source for your jobs on the go. Longevity’s ForceCut plasma cutters from 40-60 amps are all dual voltage!
What is Duty Cycle (DC) and Why is Duty Cycle Important when Choosing a Plasma Cutter?
Duty Cycle is extremely important when selecting the right plasma cutter. Longevity plasma cutters are well know to produce outstanding duty cycle ratings at 60% or higher, nearly doubling the leading brand plasma cutter which produces only 35% duty cycle.
he most common way to measure the duty cycle is in minutes. If you are cutting for ten minutes at 60 percent duty cycle or mass amperage on the plasma cutter, your plasma cutter will only allow you to cut six minutes continuously based of the duty cycle. In comparison to the leading brand that has a 35% duty cycle, they would only be able to cut for three and half minutes.
Another important aspect of duty cycle is the size of the plasma cutter for instance, our Longevity ForceCut LP-50D plasma cutter has a 60% duty cycle at 50amp, but when turned down to 40amps, it has a 100% duty cycle and the Longevity ForceCut LP-80 has a 60% duty cycle at 80amps, but 100% duty cycle at 60amps for around the clock non stop continuous cutting, thus it very important to select the right size plasma cutter in terms of amps and duty cycle.
Deciding between Pilot Arc vs. High Frequency Plasma Cutters:
Pilot Arc technology is the latest starting mechanism for a plasma cutter on the market today. Although both methods are efficient for plasma cutting, Pilot Arc allows for a user to start an arc in the air vs having to be up close with the plasma torch to the workpiece. This allows for longer consumable life because you do not have to scratch start, touch start or be extremely close to your workpiece to get an arc as seen in High Frequency Plasma Cutters.
In addition to Pilot Arc plasma cutters having the more efficient arc starting option, they also do not interfere with any electrical appliances as they do not use high frequency winding to initiate the arc. This allows for Pilot Arc units to safely be used around numerous electrical appliances, and including CNC Cutting Tables that have computers.
However, in argument for High Frequency Plasma Cutters, the arc from High Frequency plasma cutters is more stable, and most appliances are already shielded from such interferences. The advantage of High Frequency plasma cutters is that they are less expensive and produce a more stable arc in comparison to Pilot Arc torches and plasma cutting machines.
What type of plasma cutter is best for CNC Tables?
As addressed earlier, pilot arc plasma cutter technology is considered better for CNC tables as there is no possible interference with the CNC Table’s computer. I addition, since pilot arc does not require a contact start, setting up a Pilot Arc plasma cutter to work with your CNC Cutting Table is much easier.
To argue in favor of High Frequency plasma cutters, we have had many past customers create CNC tables and use the Longevity High Frequency plasma cutters on the cutting tables without any issues. We have attached the following youtube video that clearly shows how well our High Frequency plasma cutters work on CNC Cutting Tables and the customer’s home made CNC table with the Longevity LS-160P Plasma Cutter Combination welder as the source for the plasma cutting:
If you would like to know more about home made cnc plasma cutting tables and would like to ask the builder some questions, please click here
Knowing the right amperage:
We briefly touched on this topic before. Knowing your amperage requirements goes along with knowing how thick, how fast, and how often you will cut the desired metal in question. It is generally better to get a more powerful plasma cutter that has more amps. However, you do not wan to overdue it. In general, you will want to get a plasma cutter that you will operate at 75% capacity, which leaves room for cutting thicker than usual material and will also allow you to cut your usual material at a good pace
Which technology Mosfet or IGBT? Mosfets vs. IGBT Explained.
MOSFETs defined as metal–oxide–semiconductor field-effect transistor and IGBTs defined as insulated gate bipolar transistor technologies were developed around the late 1970’s and early 1980’s and are heavily utilized in all of today’s power electronics, including Longevity plasma cutters and welders. In terms of performance, MOSFETs and IGBTs operate in the same manner with a few differences in terms of voltage. The IGBT combines the simple gate-drive characteristics of the MOSFETs with the high-current and low–saturation-voltage capability of bipolar transistors by combining an isolated gate FET for the control input, and a bipolar power transistor as a switch, in a single device. The IGBT is used in medium- to high-power applications such as switched-mode power supply, traction motor control and induction heating. Large IGBT modules typically consist of many devices in parallel and can have very high current handling capabilities in the order of hundreds of amps with blocking voltages of 6,000 V.
MOSFETs have three operating modes depending on the electronics’ requirements such as the weak inversion mode, Triode Mode, and the saturation mode. What makes MOSFETs popular is the cost of production, the reliability, and the voltage they can handle
Now the reason Longevity welding and plasma cutting equipment offers both Mosfet and IGBT technologies is because both technologies are popular and the welding world demands certain characteristics from each welding machine. For example, for more complex machines that require higher voltage capabilities, Longevity uses the IGBTs because of their capacity threshold to hold voltage at higher amounts
For plasma cutters and welders that do not require higher thresholds of voltage, Longevity uses MOSFETs because they handle lower voltage amounts more consistently. Deciding which technology is more stable will be determined by the unit of purchase and our sales staff can point you in the right direction. The IGBTs are more expensive than the MOSFET units but they are also determined to be more reliable with certain plasma cutters and welders. With some of the plasma cutters or welders, Longevity will carry only either the MOSFET or IGBT depending on the requirements of that machine in order to best sustain a quality product. We have tested and sold many IGBT and MOSFET machines and have engineered the perfect combination of which Longevity plasma cutter or welder runs best on either MOSFET or IGBT technology
In any case, Longevity will establish its industry leading warranty on both MOSFETs and IGBTs plasma cutters and welders for 5 years covering both parts and labor so your purchase will be guaranteed no matter which technology you purchase!
Consumables and Operating Cost: Which consumables for the plasma cutter are better and how much will they cost me down the road?
Deciding on which brand machine to purchase based on the pricing of consumables is also a very smart consideration to make. Longevity plasma cutters are well known to be equipped with affordable consumables for your plasma cutters far below the leading brand pricing. What this means is that you have less overall operating expenses because each tips, electrode, shield cut, and gas diffuser is far less priced and more dispensable than an average unit that sells their consumables for 5 times our prices. Not only are you saving on the cost of our machines, but you are also pocketing hundreds from using our consumables.
Choosing the right consumable depends on the torch you have and what you are trying to cut. For example, Longevity offers both small and large consumables for the plasma cutters because they are meant to cut different thicknesses of metal. The larger or longer consumables are generally meant for cutting material that is thicker, but the consumables will also last longer because they are larger in size. How thick? It depends on the amperage of the cutter, the torch, and the consumables, but our charts will help you choose the right consumables. Please remember that not all consumables will fit all the torches so it is very important to select the right consumable that will fit your torch head.
How long will consumables on a plasma cutter last?
Depending on the plasma cutter’s power, the type of torch, the type of consumable, and lastly the operating technique, the plasma cutter consumables can last anywhere from 30 minutes per tip and all the way up to 3 operating hours.
In general, the bigger the consumable tips, the greater the duration you will experience from each consumable on the plasma cutter torch. When selecting a plasma cutter, make sure you purchase some consumables and take advantage of the free shipping. To review our consumables please click the Longevity Plasma Cutter Consumables page.
