An experienced plasma operator with a well-maintained plasma cutting system can save your business several hours of downtime and money in terms of operating expenses. These savings can result in more profits for your business. However, the key to a successful operation is to avoid the common plasma cutting mistakes that occur often.
You may notice that often the consumables have been used until they are completely worn. Making use of severely worn consumables not only ruins your finished parts, they can result in the failure of the plasma torch and operational downtime. You can estimate the condition of the consumables by inspecting them periodically, especially if you notice the quality of the cut deteriorating. It is a good idea to maintain a record of the average consumables life over time and create guidelines for the expected consumable life on basis of the material type, thickness and amperage and once the average life is established, you will know when to replace the parts and prevent failure of the torch.
Using Incorrect Parts and Parameters
The consumable selection essentially depends on the type and thickness of materials being cut, the plasma gas, amperage and other parameters. The plasma cutter’s operation manual will give you instructions about the consumables to be used and using the wrong consumables can result in decreased quality of the cut and reduced consumables life. The parts must be run at the proper amperage. Typically, running the cutter at 95% amperage results in the best quality of cuts and also prolongs the consumable life. If the amperage is very high, the nozzle life is decreased, while too low an amperage causes poor cut quality.
Incorrect Torch Assembly
The plasma torch must be assembled properly so that all the parts fit snugly, which ensures proper electrical contact and also proper coolant and gas flow through the plasma torch. The consumables must be maintained and kept clean. You should ensure that only the right amount of O-ring lubricant is used as too much of lubrication can cause contamination and clogging of the torch causing uncontrolled arcing and finally leading to torch failure.
Neglecting Proper Maintenance
With proper care, plasma torches can last for years. The torch and all the components must be kept clean and any dust, dirt or excess lubricant must be cleaned by using hydrogen peroxide or electrical contact cleaner. The gas pressure, flow and coolant levels must be checked daily. Insufficient flow of gas will prevent the cooling of the consumables and also reduce consumable life. Proper gas pressure is also essential for the proper starting of the plasma arc. Also, the plasma gas supply should be clean and free of moisture, oil and particles to prevent reduced torch and consumable life.
Incorrect Piercing/ Cutting
The workpiece and torch tip distance are very important to the consumables life and cut quality. Any variations to the torch height can affect the squareness of the cut edge and the height of the torch while piercing is very important, as piercing too low will cause the molten metal to spatter on the shield and nozzle and if the plasma torch drags along the workpiece while cutting or touches the metal while piercing, the arc will be snuffed and the consumables and torch may also be damaged.
Cutting very fast or too slow can also cause problems in the cut quality. Too slow cutting speed will result in low-speed dross which collects at the bottom edge of the cut. This can also cause the kerf to widen and accumulation of spatter at the top. If the cutting speed is too fast, it will result in a narrow kerf, a bevelled edge and a hard bead of dross at the bottom edge of the workpiece. Cutting at the correct speed produces minimum dross and a clean edge that does not require much finishing work.
By preventing the above mistakes during the process of plasma cutting, you can ensure that your plasma cutter will work efficiently and the proper upkeep and maintenance can ensure that your plasma torch lasts for a long time. With proper maintenance, your plasma cutter will offer enhanced productivity, greater savings and increased profits for your business.