Guided by mirrors

Traditionally, the working optical fiber of a robotic fiber laser machine is outside the robot and connected to the cutting head. However, users incur fiber maintenance and replacement costs with this configuration, particularly when a fiber catches on an object and is damaged. Also, rapid robot movements can cause the head to become loose and less accurate after numerous cycles, according to Christon Manzella, vice president of business development and strategies for Jenoptik Laser Technologies. “If you have a fiber that goes into a cutting head and jar that head during too many cycles, you will have fatigue,” he said.

He added that a fiber can’t be bent 90° to connect it to the head, so a 12 " to 15 " fiber service loop is needed, which restricts the head’s access in tight locations when cutting, for example, structural steel and 3-D tubular metal parts.

Courtesy of Jenoptik Laser Technologies

The Jenoptik-Votan BIM robot-based fiber laser machine (inset) has a unique laser robot arm in that the feeding fiber is located only in the stationary robot shoulder and the laser beam path is integrated in the robot.

Breaking with tradition, Jenoptik and robot manufacturer Stäubli AG, Pfäffikon, Switzerland, developed the Jenoptik-Votan BIM robotic fiber laser metalcutting machine, which doesn’t have a working fiber. Instead, the laser’s feeding fiber is located in the stationary robot shoulder and directs the laser beam into the robot itself. Mirrors guide the light through holes in the robot’s gearboxes to the cutting head without any working fiber connections, Manzella explained.

The “new architecture” for transporting the laser beam to the workpiece halves the robot’s weight compared to a conventional pick-and-place robot, enabling the laser arm’s axis movements to be 30 to 60 percent quicker, Manzella noted. “Now, you have a very slick, slim head that can get into locations unachievable prior to this,” he said, adding that the head weighs 5 kg. “You can push the robot as fast as you want and not worry about any mechanical fatigue on the head due to a connection point.”

Jenoptik also offers a version of the machine with a CO2 laser, and both are capable of up to 4kW laser power. Compared to a fiber laser’s 1,064nm wavelength, a CO2 laser’s 10,600nm wavelength is high and must travel through free space instead of a fiber, Manzella said. “The machine’s architecture allows the user to choose either wavelength.”

The company will demonstrate the Jenoptik-Votan BIM at IMTS in booth N-6569.

For more information, contact Jenoptik Laser Technologies, Brighton, Mich., at (248) 446-9540 or www.jenoptik.com/laser-metal-cutting.