Galvanometric laser: what it is, how it works, and why it is more precise than a Cartesian plotter

Those who need to purchase a laser cutting and marking machine often find themselves choosing between two very different technologies: the galvanometric system and the Cartesian plotter.

In this article, we look at how a galvanometric laser cutting system works, what its components are, and how it differs from a Cartesian plotter.

We will explore its advantages in terms of precision, quality of results, and speed, and present the technologies designed and built by SEIT Elettronica.

What is a galvanometric laser and how the cutting machine works

A galvanometric laser is a cutting and marking system in which the laser beam is directed onto the material by a scanning head, rather than by a mechanical carriage that physically moves across the work surface.

Inside the scanning head are two galvanometric motors: a mirror is mounted on each of them. The motors rotate in a combined manner, changing the position of the mirrors and allowing them to direct the laser beam over the entire working area with extremely rapid movements.

In two-axis (2D) systems, the two mirrors manage movements on the X and Y planes, while focus is ensured by the F-theta lens placed between the mirrors and the cutting plane. In three-axis (3D) systems, a third focusing axis is added before the mirrors, which keeps the laser beam spot in focus on surfaces larger than 30×30 cm, but can also be advantageously used on three-dimensional cutting planes thanks to specific control software.

This second configuration is preferable when the cutting areas to be covered exceed 30×30 cm or when working on shaped objects rather than flat-laid surfaces to be cut.

Summarizing with a few additional specifications, the main elements of a galvanometric laser cutting machine are:

• Scanning head with galvanometric motors: contains the mirrors that direct the beam on the two (or three) axes, guaranteeing scanning speeds up to 100 times higher than traditional mechanical systems.
• Laser source: can be CO2, UV, or Green depending on the material to be processed; the choice of source directly affects the quality of the cut or marking on fabrics, leather, plastics, or metals.
• Cutting table: can vary in size and depth and include different material anchoring systems. This last aspect should not be underestimated, as unstable anchoring can negate even the best laser cut, causing inaccuracies.

Completing the system is the control software, which manages the scanning parameters and the interface between the machine and the cutting files.

SEIT Elettronica has developed cutting solutions using galvanometric technology that optimize cutting precision and final result quality on different materials such as fabrics and leather for footwear or leather goods.

The different types of laser cutting systems

Let us now look at the main differences between two distinct laser cutting systems: the one with galvanometric technology and the one that uses a Cartesian plotter.

Galvanometric laser cutting vs. Cartesian plotter: differences

The Cartesian plotter is a more traditional laser cutting system: it does not use galvanometric motors, but rather motors that physically move the mirrors and the focusing system along the X and Y axes via mechanical carriages.

The mirrors remain at a fixed angle, close to the cutting surface, and the beam always impacts vertically, perpendicular to the surface being worked on. It is a simple and effective configuration, but one that operates at a speed limited by the inertia of moving mechanical parts, creating geometries that do not adhere closely to the original graphics. Its pros, on the other hand, are the verticality of the cut and the high focus of the laser beam (small spot size).

In galvanometric systems, operation is different: the mirrors vary their angle, ideally creating a truncated pyramid with the scanning head at its vertex. The laser beam moves at variable angles (approximately +/- 20° relative to the opening of the trunk), working dynamically on the X, Y, and, in 3D systems, Z axes as well.

The advantages of the galvanometric laser over the Cartesian plotter

Since there are no mechanical masses to physically move across the cutting table, the galvanometric system achieves much higher scanning speeds.

On the Performa platform by SEIT Elettronica, for example, the maximum speed of the galvanometers reaches 9,000 mm/sec, a value that a Cartesian plotter cannot replicate due to intrinsic mechanical limitations.

Other advantages of galvanometric laser cutting compared to a Cartesian plotter include:

• Edge quality: the micro-movement of the mirrors reduces vibration and allows objects to be drawn perfectly, maintaining clean edges even on delicate fabrics or leathers.
• Repeatability: the galvanometric cutting machine does not distort shapes even at high speeds, an important factor when creating very small elements or details in large quantities, as well as when performing large rasters.
• Production speed: the absence of heavy moving mechanical parts on the cutting bed allows for faster work cycles with higher quality result.

These advantages make galvanometric technology the most popular choice in production environments requiring serial laser cutting on fabrics, as well as in the processing of leathers and shoe uppers, where precision and repeatability are required across high production volumes.

Cutting, engraving, marking, and laser personalization with galvanometric technology

Galvanometric technology is not only for cutting: the same operating principle, based on mirror movement inside the scanning head, also enables engraving, marking, and customization work. The mark left on the material changes, becoming deeper or shallower depending on the process, but the beam scanning logic remains the same.

SEIT Elettronica applies this principle on dedicated platforms capable of covering a wide range of processes required by the textile, footwear, and promotional sectors.

Among the most common applications, in fact, are the customization of products and gadgets via engraving and automated inline serial marking.

Strengths of the galvanometric laser for specific processing types

For these and other processes, choosing galvanometric laser cutting and engraving delivers significant and specific benefits:

• Engraving: high laser beam travel speeds (up to 9 meters per second) ensure uniform processing, without interruptions or intensity variations across the engraved area.
• Kiss cut: in cutting layered or bonded materials where only one of the two layers needs to be cut, precise management of low-power passes allows intervention on each layer with extreme accuracy, without damaging the layer underneath.
• Through cutting: high scanning speeds minimize burns on cut edges, avoiding smoke and dust deposits on the material.
• Micro-perforations: galvanometric systems execute any geometry—even minimal dimensions—without distorting it: a decisive advantage in operations requiring a high number of repeated micro-perforations.
• Ablation: the process transfers large amounts of energy in very short periods, allowing the material to sublime directly from solid to gas without taking time to burn, avoiding combustion residue.
• Workfield variation: 3D galvanometric scanning heads allow users to adjust not only the size of the working area but also the laser spot size, optimizing the beam according to the process to be performed.

Here is a comparison between galvanometric and plotter technologies across the operations described above:

Do you want to integrate galvanometric laser cutting into your company’s processes and choose the most suitable laser cutting machine based on job type, material, and required production volumes? Contact us for personalized technical consulting.