Guidance on purchasing a plasma cutter
If you need to cut anything quickly, a plasma cutter is the way to go
- For minor repairs and maintenance, you'll need a cutting tool
- You've recently started a new project that necessitates larger cutting volumes
- You're looking for a replacement for your present mechanical saw
All of these circumstances give compelling reasons to look into plasma cutting. With machine costs decreasing, smaller-sized, portable machines flooding the market, and technology providing increasing advantages and simplicity of use - it's time to seriously consider plasma for your cutting needs. Plasma cutting has several advantages, including simplicity of usage, higher quality cuts, and quicker travel speeds.
What is plasma cutting technology?
In its most basic form, plasma cutting is a technique that employs a high-velocity jet of ionised gas supplied via a constricting aperture. The plasma, or high velocity ionised gas, carries electricity from the plasma cutter's flame to the work piece. The plasma warms the work item, causing it to melt. The molten metal is mechanically blown away by the high velocity stream of ionised gas, cutting the material.
How does plasma cutting compare to oxy/fuel cutting?
Plasma cutting may be done on any conductive metal, including mild steel, aluminium, and stainless steel. Operators will enjoy faster, thicker cuts with mild steel than with alloys.
Oxy/Fuel cuts by oxidising or burning the metal it is cutting. As a result, it is confined to steel and other ferrous metals that aid in the oxidising process. Metals such as aluminium and stainless steel create an oxide that prevents further oxidation, rendering ordinary oxy/fuel cutting difficult. Plasma cutting, on the other hand, does not require oxidation to function and may thus cut aluminium, stainless steel, and any other conductive material.
While other gases may be used for plasma cutting, compressed air is the most often utilised plasma gas today. Because compressed air is easily available in most shops, plasma does not require fuel gas or compressed oxygen to operate.
Plasma cutting is generally easier for the novice to master, and it is considerably faster than oxy/fuel cutting on thinner materials. However, for thick pieces of steel (1 inch and larger), oxy/fuel is still preferable since it is generally quicker, and for bigger plate applications, extremely high capacity power sources are necessary for plasma cutting applications.
What can I use a plasma cutter for?
Plasma cutting is suitable for cutting steel and nonferrous metals less than 1 inch thick. To keep the oxidising process going when cutting with oxy/fuel, the operator must carefully regulate the cutting speed. In this respect, plasma is more forgiving. Plasma cutting excels in some specific applications, such as cutting expanded metal, which is virtually hard to do with oxy/fuel. Furthermore, as compared to mechanical cutting methods, plasma cutting is generally significantly quicker and may readily create non-linear slices.
What are the limitations to plasma cutting?
Plasma cutting machines are usually more expensive than oxyacetylene cutting equipment, and oxyacetylene does not require access to electrical power or compressed air, making it a more convenient technique for certain users.
When is oxy/fuel superior?
Oxy/fuel can cut larger portions of steel (>1 inch) faster than a plasma cutter.
What to look for when purchasing a plasma cutter?
When you've decided that plasma cutting is the best method for you, consider the following criteria before making a purchase choice.
1. Determine the thickness of the metal that you will most frequently cut
The thickness of metal most commonly cut is one of the first variables to consider. The cutting ability and amperage of most plasma cutting power sources are rated. As a result, if you frequently cut 14" thick material, a lower amperage plasma cutter should be considered. If you routinely cut metal that is 12" thick, search for a machine with a greater amperage. Even though a smaller machine can cut through a given thickness of metal, it may not make a high-quality cut. Instead, you could obtain a sever cut that barely gets it through the plate and leaves dross or slag behind. Every unit has an optimal thickness range; make sure it corresponds to what you require. In average, a 14” machine produces roughly 25 amps, a 1/2” machine produces 50-60 amps, and a 34” - 1” machine produces 80 amps.
2. Select your optimal cutting speed
When purchasing a plasma cutter, the manufacturer should offer cutting speeds in IPM for all metal thicknesses (inches per minute). If the most common metal you cut is 14”, a machine with a greater amperage rating will be able to cut through the metal considerably quicker than one with a lower amperage rating, while both will do the job. A reasonable rule of thumb for production cutting is to select a machine that can handle roughly twice your typical cutting thickness. Choose a 1/2” class (60 amp) machine, for example, to produce lengthy, rapid, quality production cuts on 14” steel. Check the machine's duty cycle if you're making long, time-consuming cuts or if you're cutting in an automatic setup. The duty cycle is simply the amount of time you can cut continuously before the machine or torch overheats and has to be cooled. Duty cycle is expressed as a percentage of 10 minutes. A 60 percent duty cycle at 50 amps, for example, means you can cut with 50 amps output power continuously for six minutes out of a ten-minute period. The higher the duty cycle, the longer you can work without stopping.
3. Can the machine offer an alternative to high frequency starting?
Most plasma cutters have a pilot arc that conducts electricity through the air using high frequency. High frequency, on the other hand, can interfere with computers or office equipment that may be in use in the vicinity. As a result, beginning approaches that avoid the possible issues associated with high frequency starting circuits may be desirable. The lift arc technique employs a DC+ nozzle with an internal DC- electrode. Initially, the nozzle and the electrode come into physical contact. When you pull the trigger, current travels between the electrode and the nozzle. The electrode then pulls away from the nozzle, creating a pilot arc. When the pilot arc is brought near to the work piece, the changeover from pilot to cutting arc happens. The electric potential from the nozzle to work causes this transfer.
4. Compare consumable cost versus consumable life
Plasma cutting torches have a number of worn parts that must be replaced, which are referred to as consumables. Look for a company who provides a machine with the fewest consumable components. A lower number of consumables means fewer to replace and more cost savings. Look at the manufacturer's specs to see how long a consumable will last - but be sure you're comparing the same data when comparing one machine to another. Some manufacturers will grade consumables based on the number of cuts made, whilst others may use the number of starts as a measurement criteria.
5. Test the machine and examine cut quality
Make test cuts on a variety of machines at the same rate of speed and on the same thickness of material to determine which machine provides the greatest quality. Examine the plate for dross on the bottom side and if the kerf (the gap left by the cut) angle is perpendicular or angular when you compare cuts. Choose a plasma cutter with a tight, concentrated arc. Max-Arc consumables are specifically intended to concentrate the plasma swirl, resulting in a narrower arc and increased cutting power on the work piece. Lifting the plasma torch away from the plate while cutting is another test to do. Experiment with how far you can move the torch away from the work item while still maintaining an arc. More volts and the capacity to cut through thicker plate are associated with a longer arc.
6. Pilot to cut and cut to pilot transfers check
When the pilot arc is brought close to the work piece, the conversion from pilot arc to cutting arc happens. The mechanism for this transmission is a voltage potential from the nozzle to the work. This voltage potential was traditionally generated by a big resistor in the pilot arc current channel. The height at which the arc may transfer is directly affected by the electrical potential. A switch (relay or transistor) is employed to open the current route once the pilot arc has transferred to work. Look for a machine that can make a rapid, positive transition from pilot to cutting at a high transfer height. These machines will be more forgiving to the operator and will support gouging more effectively. Cutting expanding metal or gratings is an excellent technique to assess transfer qualities. In these cases, the machine will need to swiftly transition from pilot to cut and back to pilot. To get around this, they may suggest cutting expanding metal with simply the pilot current.
7. Check the machine’s working visibility
When working on an application, you should be able to see what you're cutting, especially when tracing a pattern. The shape of the torch helps with visibility; a smaller, less bulky light, as well as an expanded nozzle, will allow you to see where you're cutting better.
8. Look for the portability factor
Many customers utilise their plasma cutter for a variety of cutting applications and require the equipment to be moved throughout a facility, job site, or even from one location to another. It makes all the difference to have a lightweight, portable unit and a method of transportation for that unit, such as a valet type undercarriage or a shoulder strap. Additionally, if floor space in a work area is limited, having a machine with a small footprint is valuable.
You'll also require a machine with storage for the work cord, torch, and supplies. Built-in storage enhances mobility significantly because these things do not drag on the ground or become misplaced during machine movement.
9. Determine the ruggedness of the machine
Look for a machine that is durable and has protected controls for today's harsh job site conditions. Fittings and torch connections, for example, that are shielded will last longer than ones that are not. Some machines have a protective cage around the air filter and other machine components. These filters are essential because they ensure that oil is eliminated from the compressed air. Arcing and reduced cutting performance can be caused by oil. It is critical to protect these filters because they guarantee that oil and water, which lowers cutting effectiveness, are removed from the compressed air.
10. Find out if the machine is easy to operate and feels comfortable
Look for a plasma cutter with a large, simple-to-read control panel that is straightforward to operate. A panel like this enables someone who does not typically use a plasma cutter to pick it up and utilise it. Furthermore, a machine with clear procedural instructions written on the unit will aid in setup and troubleshooting. What does the torch feel like in your hands? You want something with superb ergonomics and a comfy feel.
11. Look for safety features
In addition, seek for a machine that has a three-second pre-flow safeguard that alerts users to make sure all body parts are free of the nozzle before the arc starts.
About AES Plasma Cutters
AES offer the largest range of plasma cutters for sale online in the UK. We offer quality brands of plasma cutters at wholesale prices. If you are looking to invest in a Plasma Cutter it is critical you get the right tool for the job, so please contact us if you have any concerns or questions.