What's the difference between a laser plotter and a galvo laser?
Laser machines for engraving and marking 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 via X and Y axes. Galvo lasers, by contrast, guide the laser beam using fast-moving mirrors. Below is a guide to help you determine when each laser type should be used.
Differing architectures of laser plotters and galvo lasers
The main difference between flatbed lasers and galvo lasers is the manner in which the laser beam is directed onto the material. With flatbed lasers, the laser beam is deflected 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.
Advantages of laser plotters and galvo lasers
A comparison of their features
Flatbed lasers typically have larger processing surfaces than galvo lasers. Trotec laser machines have processing areas 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. The size of the machine limits the processing 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 (310x310 mm) for fiber lasers and up to 19.7 x 19.7 inches (500 x 500 mm) 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 (1100x600 mm) 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.
Production environment and speed
Flatbed lasers (or laser plotters) are typically operated as stand-alone machines. This means they always work independently from other production machines. The materials are taken to the laser machine, processed there, removed and processed further or sold directly depending on the product. Processing times also vary according to application. Some jobs take only a few seconds, while other take several hours. 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 also 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. 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.
Details on the JobControl® laser software for flatbed lasers
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 put together correctly after laser cutting.
Speed is a 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 for optimal results. Lenses (different focal lengths) and processing tables, in particular, have a substantial impact on the result. 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 a 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.
- High focus tolerance provides tremendous benefits when working with products that are not 100% plane. Examples: Tools, jewelry, watches, machine components, medical implants and instruments, advertising.
- Deep engraving on metals possible
- Black discoloration of anodized aluminum possible
- Capabilities to reproduce colors on steel are possible
- Trotec lasers are also available as Speedy flexx. This patented 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).
You need more information about laser plotters or galvo lasers?
Our laser experts are happy to answer your questions about the differences of laser machines. They will help you to figure out which laser type suits best for your applications.