A French company producing laser machines for engraving logos on watch components has automated the process with vision technology. Laser Cheval’s laser engraving machine can process up to 1,200 workpieces per batch over a 20-hour period, with positioning tolerances of less than 50µm.
Laser Cheval's logo engraver is equipped with motor-driven axes. Controlled by a Cognex vision system, these axes position each one of the 1,200 workpieces precisely, loading up to 12 at a time in any sequence. The solution is based on VisionPro vision software from Cognex.
Logos have to be engraved on extremely small watch components, for example watch crowns measuring 5mm to 8mm in diameter. Formerly, each workpiece was manually and precisely positioned under the laser head, one by one. The logos were then engraved on the workpieces. Finally, each piece was visually inspected for engraving quality by an operator who had to be present constantly to carry out these tasks.
VisionPro automatically locates each workpiece, regardless of its position on the work table. It then communicates the precise coordinates of the workpiece (x, y and θ in the laser's coordinates) to the axis control system, which moves the workpiece under the laser engraving head with a positioning precision far superior to tolerances obtained manually.
‘VisionPro proved to be the best choice in terms of vision tool performance; flexibility, with programs based on a rich, comprehensive object library; integration with our development tools; and quality and range of integrated graphics components,’ said Michel Bertin, IT development director at Laser Cheval.
With the automated system, the customer only carries out a few quality checks on the logos, using sampling techniques.
