how do laser cutting machines work
Why lasers are used for cutting
Lasers are used for many purposes. One way they are used is for cutting metal plates. On mild steel, stainless steel, and aluminum plate, the laser cutting process is highly accurate, yields excellent cut quality, has a very small kerf width and small heat affect zone, and makes it possible to cut very intricate shapes and small holes.
Most people already know that the word “LASER” is actually an acronym for Light Amplification by Stimulated Emission of Radiation. But how does light cut through a steel plate?
How it works
A laser cutting machine works by focussing a beam of laser light onto a piece of material. The laser light is so high powered, that when focused, it raises the temperature of the material to be cut high enough to melt or vaporize the material, in the small area the beam is focused. Often, an assist gas is used to help push the molten material from the cut area. This is especially true for cutting metals or thick sheets of material like plywood.
To cut shapes, the laser head is moved, using some form of gantry to position the beam over new material, causing a line to be cut instead of a small pinhole. The types of motion systems include rack and pinions, ball screws, and linear motors. Linear motors are most expensive, but are fastest and most accurate. Rack and pinions provide nearly the same speed and accuracy, but for a lower price. Some small hobbyist lasers might also use timing belt and stepper motors to move their laser head. In all cases, a system with serves, and encoder feedback adds greatly to machine cutting accuracy, as does a rigid frame, isolated from vibration.
As for the type of laser used for laser cutters, typically industrial lasers use CO2 or fiber lasers, with the occasional diode laser or Nd:YAG disk laser sprinkled in, while hobby lasers are typically sealed CO2 or diode lasers, of lower power. The industrial lasers are typically 1–10kW fiber laser cutting machine, while the hobby lasers are typically somewhere between .25 W to 40W, so industrial lasers are 100-1000 times stronger than hobbyist lasers.