Laser Cutting 101

cnc-cuttingSo how does a laser actually work? It starts with the word itself which is an acronym for “Light Amplification by Stimulated Emission of Radiation”. For the layman, it means “you’re cutting stuff with a very bright beam of light” (which is totally AWESOME even by science fiction standards). Your imagination is the only limit to the kinds of shapes that can be cut using a laser, because it’s fast and accurate. Lasers are a great way to cut all types of metal up to 1 inch thick. Lasers use intense light to produce heat (think of the sun shining through the tip of a pencil). A laser is also not right for every cutting purpose. A laser would melt most plastics and rubber and because the energy is light, it does not work well on material with a reflective surface. So lets think of an application where a laser might be used and walk through the process. In this case, we’re cutting 1/8 thick steel into the shape of a star as part of a holiday decoration.

Lasers are operated by computer numeric controls (CNC) which allow the shapes design to be uploaded into the machine. Since we are going to be making a lot of these star shapes we need to figure out how to “nest” the parts in a pattern that makes the most efficient use of material. Most lasers will accept a sheet of steel 8ft x 4ft, and the goal is to make as many parts as you can from each sheet. The Operator can program the shape or use computer data to upload the shape from the design program into the laser. This would be an example of CAD/CAM (computer aided design/computer aided manufacturing). Let’s assume were programmed and ready to run… the fun stuff starts.

A sheet of material 8ft x 4ft, 1/8 thick, is lifted on to the “bed” of the machine…..the bed is actually a tank of water covered by a grate. Why the water? Because when we start the laser beam, it’s going to cut right through that 1/8 steel and will keep cutting anything in it’s path until it runs out of energy. The water absorbs the beams energy….which means the grate has to be replaced every so often because you keep cutting away pieces of it while you make parts. A lasers power is measured by watts and the higher the wattage, the thicker the material that can be cut. So, we have material in the machine and the program is written, now time to hit the start button.

A beam of light is generated and starts passing back and forth between mirrors, that light is “stimulated” and “amplified” into a very small beam……the laser contains a special gas which “excites” electrons in the light beam, making for one powerful and very hot cutting tool. The beam is projected out of a “lens” which is moved in the desired shape by the CNC controller, producing our star shapes. After a few minutes the process is complete, the leftover “web” is removed and finished parts taken off the bed. Time to load another sheet and make more parts!

For custom shapes made from steel less than one inch thick, the laser is the best option for speed, accuracy and efficiency. Lasers produce a clean cut edge with no burr which is typical found in a machining or stamping process. It is not surprising that this technology has found so many applications, from measuring devices to medical and military uses. So harness the power of the sun with Monroe, we are experts in using lasers in manufacturing and are willing to help you discover how to put this amazing process to work for your project or product.