With a good quality plasma cutter, the serious do-it-yourselfer can lower cutting costs while improving productivity. Craftspeople who’ve experienced air plasma arc cutting can see the huge difference from standard oxyacetylene or mechanical cutting involving the use of snips, shears, saws and cut-off wheels. The plasma cutter eliminates the need for going through a preheat cycle and is able to cut any electricity-conducting metal while enabling effortless portability and reducing the heat-affected zone. Cuts obtained are characterized with small kerfs (cut ends or slits). If you need to trace shapes, cut holes, bevel, gouge or pierce smoothly and in less time, make sure to observe the following procedures for using a plasma cutter.
Make sure everything you need is in the package
A complete plasma cutter package includes all the torches and cords for use with the plasma cutter itself. Make sure you have a work or ground clamp as well. You also need the right power cord. Some models come with pigtail adapters for 220-volt current and 110-volt current. Plug the correct pigtail adapter to the power cord.
Everything in the package comes in a heavy-duty carrying case, which keeps all the items required to operate the machine in just one place, including consumables and consumables cases.
Set up the workpiece
Take the ground clamp and affix it to the workpiece.Make sure the ground clamp is attached close to the exact spot where you will cut. Although the metal you work on has light surface rust in places or has some heavy coating of mill scale, those factors won’t really cause plenty of issues to what you are going to do. One great advantage to plasma cutting is the method can cut through thick rust, but you may not be able to get a good ground through. To handle this issue, just wiggle the clamp through the surface till the teeth are able to dig through the rust, Should the rust be really heavy on the surface, work it off using a good quality grinder to give the ground clamp a spot on which to attach. The working surface should be safe while enabling you to move freely. Using a grate or something similar as a worktable should be just fine.
Select the correct tip suitable for the amperage setting
A tip used for lower amperage settings features a small orifice to ensure maintenance of a narrow stream of plasma at the exact low setting. If you have an 80-amp setting and use a tip designed for 40 amps only, the orifice of the tip will get distorted and this will also decrease the life of the consumable. On the other hand, you won’t be able to focus the plasma stream that well when you work at lower settings utilizing an 80-amp tip, which also results in a wider kerf. To cut in corners, utilize patterns or work in tight areas, you need to get further reach via extended tips.
With faster travel speeds, you can get cleaner cuts, especially on aluminum. Adjust the machine to full output and vary your travel speed as well when working on thick material. For thin material, use low amperage settings and change to a low-amperage tip to get a steady narrow kerf.
Set up the machine with the right air pressure
Plug the machine in. Connect the air hose to the back of the machine. Turn the air flow on. Make sure you have clean, dry air, as running wet air can also result in a waste of consumables, and the machine is not going to cut as well as it should. Blow the moisture out to drain the the bottom of the air compressor.
Some units have a regulator knob sticking out the side of an air compressor tank, which allows you to dial in the exact air pressure you need. Other models have an LED regulator. A top-mounted knob is to be turned until the middle LED lights up, indicating the machine is ready to go. An automatic internal regulator ensures safe operations. Set the current based on the gauge rating of the metal you will be working on.
It will be a good idea to make a sample cut first using the same type of material you will be cutting to make sure you have set the right setting and travel speed. The trigger activates the machine. Typically, the trigger is equipped with a safety system that has to be lifted first before the trigger itself is depressed. Engage the pilot arc, which burns through any rust, paint or grease that may be on the workpiece and comes in contact with the workpiece itself. At this point, the larger cutting arc takes over.
Make sure the cutter stays close to the metal. Use the guide around the nozzle to cut with templates when available. Some plasma cutters come with a drag shield, which enables the user to leave the torch on the surface of the workpiece while ensuring that the tip doesn’t come in contact with the metal. Allowing the tip to touch the surface of your workpiece will not only shorten consumable life but will also ruin the quality of the cut.
For models without a drag shield, use your other hand to support the hand you are using to hold the plasma cutter.
The cutting arc should exit the workpiece at a 15- to 20-degree angle opposite the travel direction. If the arc travels straight down, the user may not be moving at an optimal speed. On the other hand, you are moving too fast if the arc sprays back.
After cutting, turn the machine off and detach the clamp.