There was a time when lasers were pure science fiction, but they have long since become part of our daily lives. Laser engraving is one of the more common uses. The process is fairly simple, but it is also highly versatile and useful in a wide variety of circumstances. That has earned laser engravers a place in many business environments, workshops, and even the garages of hobbyists. They are likely to become even more common over time as more and more people get used to taking advantage of them, so it is a good idea for everyone to learn a little bit about them.
Many people expect laser engravers to be highly complicated pieces of machinery, but they are actually relatively simple. They consist of three main components, which are a laser, a table or other surface, and a control mechanism.
The table is one of the most complicated parts. Not only does it hold the item that is being engraved, it also provides the structure that allows the laser to move around. Designs vary, but most of them involve a simple bar that moves up and down on the table. The laser is mounted on the bar, and the mount can move left and right. The combination of the two allows the laser to move over any point on the table.
The control mechanism governs that movement. It can take a pattern and convert it into a series of movements. When the laser is over a point that needs to be engraved, it turns on. When it is moving over a point that needs to stay blank, it turns off. The entire system allows for reasonably precise control over the laser, so the engraver can make very precise patterns and make sure that the end result is the same every time.
Lasers can work on most materials, although they do struggle with stone. Glass is a special case because it will get small fractures when exposed to a laser. A clever designer can take advantage of that to get unique effects, but it does mean that it is fairly rare to use a laser engraver in that context.
Most other materials work very well, but the person who programs the engraver does need to be aware of the intended material for the pattern. Each one needs different settings on the laser to make sure that the engraving comes out neatly. Wood and other organic materials generally need a fairly weak laser that is set to a low power level. Using too much power will make them catch fire and ruin the final product.
Metal forms a stark contrast. It resists heat very well, so only a laser with a high power level will engrave it successfully. The metal can be treated with a variety of coatings to create unique effects, and these coatings also change the settings that are required. Plastics vary massively depending on the specific type, so each one will need even more specific settings, but there are special plastics that are designed for laser engravers that work extraordinarily well.
A laser produces a beam of energy. When that energy enters an object, it gets hot. In most cases, the object will absorb the energy quickly, and lasers that have more power will cause the object to heat up even more quickly. Ablation will occur at very high levels of energy, which causes some of the material to evaporate. The rate of evaporation and the amount of energy that is necessary to cause it will depend on the material. This is the main process that laser engravers use to remove material from objects, but it is not the only option.
Many engravers can also use other marking techniques on certain materials. For example, most of them can simply char would rather than using ablation when they are set to a low power level. They can also trigger reactions that change the color of some chemicals. Ultimately, laser engraving is simply a technique that allows users to apply a large amount of energy in a very precise pattern to trigger physical changes in an object, and there are many ways that clever designers can use it to produce beautiful results.