Laser cutting is a process of thermal separation, so it’s not exactly ‘cutting’ as we know it. The material, when struck by the laser beam, heats up to the point of melting or vaporizing completely. After the laser beam has completely passed the material at a certain point, the cutting process itself starts. The system follows the selected geometry, separating the material. Depending on the application, the gases generated by the process can have a beneficial effect on the final result.
Laser cutting, plasma cutting, mechanical cutting – comparative cutting processes
There is no single type of metal laser cutter, so it’s important to understand the different machines. Plasma cutting is a heat-cutting process often used in the cutting of steel, stainless steel and aluminum. In comparison with laser cutting, the main disadvantages are lower cutting quality, higher energy consumption, greater dust generation and noise. However, in cutting electrically conductive materials, plasma cutting is often more indicated by its flexibility.
Regarding the mechanical cutting process by chip removal, the laser has several advantages. These include non-contact processing, reduced set-up costs, reduced contamination and more flexibility in processing. Each processing method will have its advantages depending on the material and the application, as for example in the cut of multiple stacked pieces.
Laser Cutter Preparation
In the focus mode, the car can be moved manually on the XY axis. However, movement on the Z axis (height) is always done by the panel.
Before use the cutter must be calibrated so that the laser is focused exactly on top of the material to be cut. If the focus is poor, the material may become burnt or may not even be cut off. To calibrate, it is necessary to place the material on the cutting table and position the laser in the center of the material.
The panel has commands to move the car in all directions. For faster calibration, the X / Y Off button turns off the XY-axis motors and allows manual movement of the car to the desired position. The vertical arrows allow movement on the Z axis (height); you can not move the height manually.
The printing table is a metal “hive”, which even needs to be removed for periodic cleaning. The material to be engraved or cut should be placed directly on the table, taking care that it is well aligned and flat. If the material is poorly positioned, the height of the laser may be wrong, damaging the operation.
The calibration timing should also be used to check if the cutting car is clean. The cutting car has a mirror system and a lens that is used to focus the laser at the exact point. In the photo above it is possible to see the bottom of the mirror tilted at 45 degrees; the lens sits right under the mirror. It is essential to keep the lens and mirror clean, without any blemishes; any stain can cause overheating and consequent lens breakage. The recommendation is not to try to clean the set with any material, and if it is dirty, ask for the cleaning or even the exchange.
In the photo you can see the calibration accessory. The height must be calibrated so that the paper can pass under the nozzle of the accessory with a slight resistance, without being trapped. Also see in the car the yellow lens, which must be completely clean.
Finally, the calibration! The cutter comes with a metal accessory for easy calibration, which is a metal “spout” (visible in the photo on the side) that fits into the carriage. It should be possible to pass a sheet of plain paper under the nozzle so that it passes firmly but does not get stuck with excessive friction. The user goes up or down the table using the dashboard commands until he is satisfied with the result. Once positioned, simply select the “Reset” command on the panel to exit the focus mode.