What is a CNC Plasma Cutter and How Does it Work?
CNC plasma cutter is an automatic cutting tool that uses the momentum of high-speed plasma arc to cut metal with features of easy to use, convenient operation, and high precision. It is widely used in automobiles, locomotives, chemical machinery, nuclear industry, general machinery, construction machinery, and steel structures.
Modern CNC plasma cutting machines are driven by CNC controllers, which can realize automatic arc ignition, and the success rate of arc ignition is more than 99%. The CNC control system supports various design software, and can also use U disk to exchange cut files, which is very convenient to operate.
How to use a CNC plasma cutter for beginners? Let us understand step by step.
Preparation Before Operation
1. Before the CNC plasma cutter is powered on, it is necessary to check whether all switches are in the off position, and whether the rotary switch at the rear is in the horizontal position.
2. Turn on the power supply of the main switch cabinet before starting the machine to make the two cables have electricity.
3. Move the circuit breaker in the electrical cabinet of the CNC plasma cutting machine to the ON position.
4. Turn on the system control power with the key switch, and the main interface of the display should appear at this time.
5. Turn the rotary switch at the rear of the plasma power supply by 90° to the vertical position, and the power indicator light of the device will be on.
6. Turn on the air compressor (compressor flow rate is 1m3/min), and adjust the air compressor pressure control switch, so that the output air pressure of the compressor is 6.1-8.2Bar.
7. After connecting the machine (be sure to connect the safety ground wire), check carefully, if everything is okay, you can proceed to the next step.
8. Close the power switch to supply power to the machine.
Note: The input AC current should not be too small, otherwise the machine will not work normally. At the same time, check that the fan in the machine should meet the regulations, otherwise, adjust the phase of the input power until the direction of rotation is consistent.
9. Put the "Power Switch" in the "ON" position. At this time, the "Power Indicator" light is on. However, the "Phase Loss Indicator" light should not be on, otherwise, there is a phase loss phenomenon in the three-phase power supply, which should be checked and solved.
Note: If the safety grounding wire is not properly connected to the mainframe, the phase loss indicator may show wrong results.
12 Easy Steps to Operate a CNC Plasma Cutter
Step 1. Check whether the intake air pressure of the plasma power supply meets the requirements and whether there is an emergency signal when the plasma power supply is turned on
Step 2. Press to start cutting and check whether there is an emergency signal for the plasma power supply to start after the cutting torch performs the positioning action. If an emergency signal is activated, clear the fault according to the plasma power supply manual.
Step 3. Turn on the switch that controls the numerical control in the power distribution cabinet of the workshop, turn on the main power supply of the cutting machine cabinet, turn on the power supply of the dust removal controller, and start the dust collector.
Step 4. After the CNC control system is fully started, turn the emergency stop switch to the right, and turn the power button to the right to power on the drive.
Step 5. Customize each axis to return to zero, check and replace the plasma wearing parts, and close the plasma power circuit breaker.
Step 6. Turn on oxygen and compressed air, and the pressure of each gas is 8.3bar+-10%.
Step 7. Call the cutting program and the corresponding database of the program for correction.
Step 8. Save the program starting point to the reference point, and turn on the plasma power and adjust the gas settings.
Step 9. Start cutting, press the start cutting button, the CNC control system accepts the external signal and then sends out the start cutting signal or the CNC cutting system directly sends out the cutting signal, after the plasma cutting torch is selected and then the control system is raised, the plasma cutting torch executes the positioning action, and the torch nozzle It touches the steel plate and then rises to the perforation height. After the height adjustment control system completes the positioning action, it sends a start cutting switch signal to the plasma power supply to start arc ignition and perforation. After the perforation is completed, the plasma torch starts to move to cut the metal.
Step 10. If you encounter a problem in the middle, press the stop button to stop cutting, and continue cutting after eliminating the problem.
Step 11. After cutting, turn off the power of the machine, computer, plasma power, and each gas valve.
Step 12. Finally, clean the CNC plasma cutting table and refuel for care and maintenance.
6 Important Things to Consider
CNC plasma cutting machine should master some details when working, otherwise it is easy to fail due to unstable cutting quality and frequent replacement of wearing parts.
1. The CNC plasma cutter should adopt a reasonable cutting distance.
According to the requirements of the manual, a reasonable cutting distance is adopted, which is the distance between the cutting nozzle and the surface of the metal part. When perforating, the distance that is twice the normal cutting distance or the maximum height that can be transmitted by the plasma arc should be used as much as possible.
2. The CNC plasma cutting should start from the edge.
CNC plasma cutting machines try to cut from the edge rather than perforation. Small CNC plasma cutters use the edge as the starting point to prolong the service life of the consumables, so the correct method is to aim the nozzle directly at the edge of the metal part and then start the plasma arc.
3. You need to reduce unnecessary "arc starting (or arc guiding)" time.
Both the nozzle and the power burner are very fast when starting the arc, so the torch should be placed within walking distance of the cutting metal before starting.
4. You should try to keep the cutting torch and consumables clean.
Any dirt on the torch and consumables will greatly affect the function of the plasma system. When replacing consumables, put them on a clean flannel, check the connection rib of the cutting torch frequently, and use a hydrogen peroxide-based cleaner to clean the electrical contact surface and the nozzle.
5. The cutting nozzle cannot be overloaded.
Overloading the nozzle (that is, exceeding the operating current of the nozzle) will cause the nozzle to fail faster. The amperage should be good at 95% of the nozzle's operating current. For example, the current intensity of a 100A nozzle should be set to 9 or higher.
6. The perforation thickness should be within the allowable range of the CNC plasma cutting system.
A small CNC plasma cutter shall not perforate the steel plate exceeding the working thickness, and the general perforation thickness is 1/2 of the normal cutting thickness.
By reading this guide, you should know how to right operate a CNC plasma cutter. Now, start to enjoy the happiness with plasma cutting for your metal fabrication business.