The correct laser focus setting (i.e., the distance between the laser head and the material to be engraved) is key to achieving optimal processing results.
Four methods of identifying a proper focus setting are described below.
Trotec's Sonar TechnologyTM (patent pending) enables the highest level of accuracy when focusing on your workpiece, regardless of where it is placed on the laser bed. With only one press of the Z-positioning keys, an ultrasonic sensor on the laser head detects the material's surface. The focal point is calculated automatically, and the Z-axis moves into the appropriate position.
Light Bar Focus
This focus mode involves the use of sensors ("light barriers") which are laterally installed in your laser's interior. The work table automatically rises when this focus mode is enabled using the laser's keypad system.
The upward movement of the table stops as soon as your workpiece passes the light barriers. The correct focal point is then automatically calculated, and you can begin cutting or engraving.
The light bar focus is ideal for flat and opaque materials of an unknown thickness.
The optimal focus point is calculated in the JobControl® laser software. You simply enter the workpiece's thickness and your lens' focal distance. JobControl® can determine the laser's exact work table position due to the bi-directional connection between your computer and laser system.
Based on the information you entered in the software program, the table moves to the correct position with the single press of a button.
This software-based focusing is ideal for processing flat materials with a known thickness (e.g., 6mm acrylic).
Each focus tool's length is identical to the optimal focal length of its corresponding lens. For instance, a 2" focus tool has the same length as the ideal focal length of a 2" lens. Each tool is also appropriately colour-coded for easy identification.
The correct laser focus setting can be conveniently determined using a focus tool. The laser operator simply hangs the focus tool on the laser head, and proceeds to manually raise the work table until the tip of the tool touches the workpiece's surface.
This method is especially useful if you work with a variety of materials, if the material thickness is unknown (or can not be measured), or if you are processing round or cylindrical objects.