In the field of welding technology, the welding engineers at Metallbau & Schweißtechnologie Zentrum GmbH Blankenburg, or MSZ for short, have mastered many high-tech joining processes: "We focus less on standard tasks and more on the production of high-quality, production-ready assemblies and special designs in many material combinations. Where things get metallurgically tricky, we see the challenge and take on this exciting task," says company founder Wilhelm Krüger Sr. Other special features of the company are its high level of vertical integration and high-tech machinery, which includes more machines than employees. In addition to a welding robot from Yaskawa, there are laser, plasma and flame cutting systems as well as various types of bending machines, press brakes, automatic saws and everything else needed for a metalworking company to be able to produce its own welded constructions.

"Thanks to this equipment, we are now able to offer our customers from the machine, plant and rail vehicle construction sectors complex welded assemblies and system components from a single source," emphasizes Wilhelm Krüger Sr.

No alternative to automated welding

When it comes to demanding welding tasks, the company in Blankenburg sees no alternative to mechanizing the welding machine or using robots. The human anatomy is not sufficient for the production of highly demanding weld seams with maximum precision. For this reason, the company decided to invest in a high-performance robot welding cell from Yaskawa over ten years ago.

The decision was not taken lightly at the time, the performance of all robots was compared and a Motoman HP20 with a two-axis positioner was purchased. With a reach of 1,717 mm, the HP20 is very compact and offers a repeat accuracy of 0.06.

"The HP20 is a jack of all trades and impresses with top performance for all tasks. We use it for all kinds of experiments, metallurgical research tasks, welding tasks on cast parts, welding of individual parts, but also medium-sized series. The system has mastered all of this without a hitch for over ten years. It has already paid for itself ten times over," reveals Krüger.

A standard DK-1500 rotary tilting table from Yaskawa serves as the positioner. While the rotary axis is designed to rotate endlessly, the tilting axis has a freedom of movement of ±90°. The DK-1500 is supported on bearings on both sides and has a maximum load capacity of 1,500 kg. The eight axes - six from the robot and two from the positioner - are controlled by the Yaskawa DX100 controller.

Hundreds of programs are now stored on the system and MSZ usually still has the relevant devices in stock for recurring orders, which are then immediately available. This means that some complex parts that were manufactured ten years ago can be delivered within a few days.

Flexibility without limits

Wilhelm Krüger appreciates the flexibility of the system: "In order to minimize restrictions in our wide range of tasks, we rely on an intelligent TPS/i 5000 pulsed power source from Fronius, which has a high-performance processor and a high-speed bus. This enables us to transfer large amounts of data in a short time and implement fast control loops. In conjunction with our push-pull robotic welding torch, we achieve a very stable arc and are able to weld filler materials with a diameter of more than 0.8 mm."

The Fronius Remote Control Unit RCU 5000i with full text display allows the operator to control the welding process conveniently and safely from outside the cell during operation. He can therefore actively intervene in the process and adjust parameters at any time. The result is increased welding speed, process reliability and outstanding welding results, even under the most demanding conditions.