All About Engraving Speed
Engraving speed is the commanded velocity at which the laser's motion system moves or scans the focused laser spot across the workpiece, typically expressed in millimeters per second. Scanning speed affects how long the focused spot interacts with each portion of the material and therefore interacts strongly with power, frequency, pulse duration, spot size, and pass count.
Physical effect
With the other settings unchanged, slower scanning places more pulses along each millimeter on a pulsed laser or increases exposure time per unit distance on a continuous-wave laser. Faster scanning generally reduces exposure per unit distance and can increase throughput, provided the motion system can achieve the requested speed and the laser and controller can maintain the intended output.
Pulse spacing
On a pulsed laser, the center-to-center distance between successive pulses along the scan path is approximately the scanning speed divided by the pulse frequency, using consistent units. When pulse frequency remains fixed, changing scanning speed affects both exposure per unit distance and the microscopic spacing between successive pulse interactions.
Examples
Within a tested and machine-safe marking process, reducing scanning speed may increase heat accumulation for annealing or color development. Increasing scanning speed may reduce heat accumulation and scorching on a known laser-safe organic material, or help remove a thin coating while limiting heat transferred into the substrate. A tested removal workflow may use a primary pass for material removal followed by a faster, lower-impact cleanup pass intended to reduce residue without adding substantial depth.
Motion limitations
The motion system may not achieve a very high requested scanning speed because of galvo field configuration, acceleration limits, overscan requirements, controller behavior, or paths too short to reach full speed. When the motion system slows for tight corners, those areas may receive more exposure than long straight paths unless the laser and controller compensate by modulating power. On controllers that vary commanded output with motion speed, the Minimum Power setting helps determine the power used during these slower portions of the path.
Testing
Begin with a controlled scanning-speed and power test matrix, then refine pulse frequency, pulse duration, and line interval as needed for the laser and process. Record the lens, focus method, material and surface preparation, and position within the engraving field because these factors affect whether a tested scanning-speed result remains repeatable.