Engraving and marking machines are available in two designs: flatbed lasers (also referred to as laser plotters), and as galvo lasers. With flatbed lasers, the laser beam is directed by fixed-mounted mirrors that are moved over the working surface on the X and Y axes. On the other hand, galvo lasers guide the laser beam using fast-moving mirrors. Below is a guide to help you determine what laser type should be used for specific applications.
The biggest difference between flatbed and galvo lasers is the manner in which the laser beam is reflected onto the material. With flatbed lasers, the laser beam is guided on the material along the X and Y axles by means of fixed mirrors. At the end, the beam is focused by a lens and thus applied vertically onto the material. The plotter system is installed in a housing. The larger the machine, the larger the processing area.
In galvo systems, the laser emits onto 2 rotatable, highly dynamic mirrors of low inertia. These are moved by galvanometer drives. Since hardly any masses are accelerated, the laser beam can thus be guided over the workpiece at extremely high speeds with high precision and repeatability. The marking field size is defined by the deflection angle and the focal length of the optics.
The video shows a comparison of the differing functions.
How should you determine whether you should use a flatbed or galvo laser? It depends primarily on your application. The following comparison shows you what you should consider when you are deciding which type of laser to purchase and use.
Flatbed lasers usually always have larger work area than galvo lasers. Trotec laser machines have table sizes as large as 87 x 126 inches. You can insert either a large part or many small parts into the machining area and then have the laser engrave or cut them in the same job. The size of the machine limits the work area. The larger the machine, the larger the processing area. For models with pass-throughs, it is also possible to insert parts that are larger than the processing area.
Trotec's galvo lasers have lettering areas of up to 12.2 x 12.2 inches for fiber lasers and up to 19.7 x 19.7 inches for CO2 lasers. This refers to the marking area alone. By mounting the galvo laser on an axle system (X, Y) of a laser workstation, processing areas up to approx. 43 x 23.6 inches can be realized. Galvo lasers are used with or without housing. With housings with pass-throughs or detachable side parts or without housing, even very large and bulky parts can be marked.
Flatbed lasers (or laser plotters) are usually operated as stand-alone machines. This means they always work independently from other production machines and lines. The materials are taken to the laser machine, processed there, removed and processed further or sold directly depending on the product. Processing times can also vary according to the application getting done. Some jobs take only a few seconds, while other take several hours. This depends on the details and size of the product being worked. It is common for one operator to work several machines. While one machine is processing the jobs, other machines are being loaded, or parts are being removed.
The high processing speeds of galvo lasers usually get individual jobs done within a few seconds. In order to maximize production capacity and reduce downtime occurring from loading and unloading, there are alternatives to the basic model such as semi-automatic work stations with round tables. Due to the compact structure of galvo lasers, they can be easily integrated into production lines. As a result, very high numbers of parts can be processed in the shortest possible time in fully automated operation. Only the supply of new parts must be ensured. However, even this can also be largely automated by means of conveyor belts or other handling systems.
Trotec's flatbed lasers are equipped with easy-to-use software called JobControl, which comes with the machine. The user works with the usual graphics programs (e.g. CorelDraw, Photoshop, Photopaint, AutoCAD, Adobe Illustrator, Word, Excel, etc.) and sends the laser job via a printer driver to the laser machine, where the graphics are converted into a real object.
Galvo lasers are equipped with a highly flexible, powerful but nevertheless very user-friendly software, permitting individual, intelligent and interactive program sequences to be created quickly. Everything is possible without special programming knowledge, including indexing serial numbers, time stamps, processing of lists, handling variables, and more.
Due to the design of the laser plotter ("flying optics"), the laser beam always hits the material perpendicularly. This ensures a straight cut edge, especially for thick materials (e.g. acrylic, MDF, wood). Perfectly straight edges are a mark of high quality and precision, and may be a requirement in some cases, for example if parts must be assembled together after laser cutting.
Speed is the main advantage of the galvo laser, and the advantage is especially noticable when you're working with thinner materials, such as paper, cardboard, foils, or thinner laminates. Depending on the application, 10 to approx. 65 times the speeds of a flatbed system can be achieved. Depending on the position within the marking field, however, the beam impacts onto the material at a greater or lesser angle of inclination. In the case of thicker materials, this slope of the cutting edge is clearly visible.
Each application requires its own configuration of the parameters for optimal results. Lenses (different focal lengths) and processing tables, in particular, have an impact on the final result of the product. Flatbed lasers can be quickly and flexibly adapted to the application. This is an unbeatable advantage when you are working with a wide range of individual engraving or cutting tasks.
Galvo lasers are generally purchased for one specific application, for which they are optimized. Integration into ERP systems is just as possible as the marking of dynamic contents (e.g. counting up of serial numbers, time stamps, processing of lists, etc.). A high degree of automation facilitates the marking process and the throughput time.
- Trotec lasers are also available as Speedy flexx. This technology permits CO2 and fiber lasers to be activated alternately in just one laser machine at the click of a mouse. This provides ultimate flexibility in material selection.
- Low-priced entry-level machines are available. The laser plotter is economically advantageous even for low quantities.
- Compatible with all popular graphics programs (laser software works like a printer driver).
- High focus tolerance provides benefits when working with products that are not 100% flat. Examples: Tools, jewelry, watches, machine components, medical implants and instruments, advertising.
- Deep engraving on metals is possible
- Black discoloration of anodized aluminum possible
- Capabilities to reproduce colors on steel are possible