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Five Basics to Remember for a Good Cut with Plasma

There are a few simple checks that can make plasma cutting work like a dream or can cause extreme frustration. Below are the 5 most common problems and questions people seem to have when using a plasma cutter.

1) Work Clamp (or “ground” clamp): The work clamp needs a good electrical connection. If you are cutting on rusty, galvanized, painted or dirty material, you will need to grind off a place for the work clamp. The torch will cut at its rated capacity, provided the work clamp has a good connection.

2) Consumables: If the torch consumables are worn beyond the manufacturer’s recommendation, you may experience arc outages. Normally, for tips, if the hole in the end has doubled in size when compared to a new tip, it is time to replace it. Electrodes need to be replaced when the Hafnium in the center of the electrode has reached a depth of 1\16”. Always check your manual for specific information on when to change the consumables. In standard applications, you may be able to use 2 tips for every one electrode.

3) Standoff distance: Typically a recommended standoff height is 1/16” to 1/8” off without touching your work piece. Remember electricity is lazy. It wants to take the path of least resistance. If you get too far away from the work piece, resistance between the work piece and electrode (cutting circuit) is much higher than the resistance between the tip and electrode (pilot circuit). This will cause the machine to stay in pilot and shut off after the five seconds.

4) Retaining cup: If the cup is on too tight, it prevents the electrode from moving freely. This will in turn prevent the arc from transferring. When threading the cup onto the end of the torch you should be able to feel and hear the cup switch in the torch click. Once this switch has been closed the cup does not need to be tightened any farther.

If there is any moisture in the air supply it can prevent arc transfer and create arc outages. Also, excess moisture in the system can lead to premature consumable wear. It can also cause the tips to wear unevenly which can cause problems with the kerf angle of your cut.

Following these simple guidelines will help you ensure that your machine operates to its full potential and will help extend the life of your machine and consumables.

Tim Lux
Plasma Service and Applications Specialist


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