Troubleshooting Common CNC Plasma Cutting Issues

CNC plasma cutting has transformed metalwork throughout Australia, providing accurate cuts and greater efficiency for small and large workshops. Its technology incorporates an electrically conductive gas to transmit power from a power supply through to the material, resulting in neat, accurate finishes when things go according to plan.

Even the best systems, though, are not immune from problems in cut quality and productivity. Educating your operation in troubleshooting common problems will help your operation continue to run and get the most out of your investment.

Overcoming Dross Formation Problems

Dross formation appears as slag or liquid metal adhering to your cut edge on the bottom. It reveals coarse surfaces and impacts subsequent manufacturing processes.

Several things cause dross. Slowness in cutting is a frequent main cause – too much heat builds up and not enough penetration, and too high travel speed does not penetrate at all. Cutting too near the material makes the material too hot, and too high a setting reduces arc efficiency.

Start troubleshooting by adjusting your travel speed. You can up your travel speed in small amounts if you see heavy dross formation, or reduce it slightly if you see incomplete penetration. Then check your standoff distance – most applications are optimal with a material to torch separation of 1.5mm to 3mm. Finally, check your amp settings. Larger currents are susceptible to too much dross, particularly on thinner material.

Troubleshooting Arc Voltage Issues

Arc voltage malfunctions are symptomatic of erratic cut quality, frequent arcing, or total cutting breakdown. These malfunctions are a common result of consumable wear, dirty working surfaces, or improper voltage settings.

Start with your consumables. Worn electrodes and nozzles create irregular arcs, which change in a random, haphazard way. You must replace the consumables in accordance with manufacturer instructions – typically every 1 to 2 hours of operation in normal duty cycles.

Prep your working surface. Paint, oil, or rust on your material may lower your electrical conductivity and promote unpredictable arc behaviour. Clean your exposed metal with a wire brush or grinder before you begin cutting.

Check your voltage settings against your material type and material thickness. Heavy-duty plasma cutting machine kits have recommended voltage charts – refer to these for peak performance. If issues continue, check your ground connections. A faulty or corroded ground clamp can lead to erratic voltage instability.

Correcting Cut Angle Errors

Bevelled or angled cuts rather than vertical straight edges are signs of cut angle defects. Such defects are normally caused by improper placement of the torch, worn out guide parts, or incorrect machine setting.

Check your torch holder and your guidance system first. Worn or damaged components make your torch float as you are cutting, causing uneven angles. If any components are badly worn or damaged, change them.

Verify your machine’s orthogonality with a square on a test cut. If your torch is not vertical, see your machine operation manual for adjustment procedures. Most CNC controls have program corrections for torch angle adjustment.

Also consider your cutting parameters. Excessive travel speed can cause the arc to form behind the torch and generate bevelled faces. Again, improper standoff impacts arc characteristics and generates angle problems.

Peak Physical Conditioning

Prevent most of the CNC plasma cut issues from getting into production with regular maintenance. Establish a daily routine for inspections such as a check on consumables, working surface cleaning, and proper torch height verification.

Keep up-to-date records of cutting parameters for each material and thickness. Such records help to identify patterns when problems occur and repeatable results for operators.

Remember, proper technique and quality maintenance form the foundation for consistent CNC plasma metal cutting operation. Systemic troubleshooting, when issues do arise, quickly returns your system to prime operating condition.