What is laser cutting?
CNC Laser Cutting is a computer-controlled subtractive cutting and engraving process widely used in the manufacturing of woods, plastics, metals, and other materials. Laser cutting is relatively fast, accurate, and inexpensive to operate. The cutting depth of a typical laser cutting machine is relatively narrow.
How does Laser Cutting Work?
Modern CO2 machines usually produce the laser beam in a sealed glass tube which is filled with gas, usually carbon dioxide. A high voltage flows through the tube and reacts with the gas particles, increasing their energy, in turn producing light.
A laser beam emanating from the laser tube is typically around one-quarter of an inch (240 thousandths) in diameter. This too large for practical engraving or cutting applications. In order to achieve high-quality engraving and precise cutting with your laser system, the laser beam is directed through a series of mirrors and through the focus lens.
The focus lens narrows or “focuses” the laser beam to a very small, precise spot that will enable graphic images to be engraved or cut with extremely accurate results. As the laser beam leaves the focus lens, it takes on an “hourglass” shape, with the ideal focal distance within the center of the “hourglass.”
The ideal focal distance is different with each lens. In general, the ideal focal distance is the same as the lens specification; i.e. a 1.5 inch focal length lens will have ideal focal distance at 1.5 inches from the lens. See illustration below.
1.5-inch lens
- Optional lens for high resolution engraving.
- Recommended for raster engraving above 600 DPI resolutions.
- Recommended for small font or fine detail engraving.
- Produces spot size of 0.003 to 0.0065 inches in diameter.
- Good cutting lens for thin (less than 1/16 inch) material.
2-inch lens
- Standard lens on most laser systems.
- Multipurpose for both engraving and cutting applications.
- Recommended for raster engraving from 300 DPI to 600 DPI resolutions.
- Produces spot size of 0.004 to 0.007 inches in diameter.
4-inch lens
- Produces focused beam over longer vertical distance
- Specialty lens typically used for engraving within recessed area (bowl or plate).
- Used for cutting thick materials.