Fiducials are reference points that help machines recognise where an object is in its space. When it comes to printing and cutting Xanita board fiducials are vital to ensure precise cutting that matches up with the print on the opposing side of the board.
The more accurate the cutting, the better finished applications look.
Things to keep in mind
Circles are the most suitable for camera recognition, since the midpoint of the circle is equidistant from all sides. This is the decisive advantage. A cross, for example (+), can easily be transformed into an X and is no longer recognised if the printing is rotated.
In creating the marks ensure that there is sufficient contrast between the mark and the background. A black mark placed on a white background offers very good contrast. Marks placed over printing or offering poor contrast, do not ensure easy legibility, and can result in difficulties with the recognition process. Ensure that there is adequate lighting in the surrounding work area.
The camera which sends the image signal to the software is located on the tool head. It thus always covers a specific area of the table surface which comprises approximately 30 x 30 mm. Fiducial marks should have a diameter of approximately 6 mm so that they can be easily recognised within this area.
In order to compensate for print displacement, we recommend using several fiducial marks, we use 4 Global fiducials. Global fiducials should ideally be located on a grid based system, outside of the print and cutting area, with the first fiducial located at the 0/0 point and the other fiducials located in the positive X and Y directions.
The fiducial marks have to be uniform in shape and size for optimal results. Different marks have different offset values, and reading them in can take longer than when all marks are not uniform, increasing production times.