Weber Stahl relied on a BIBER robot cutting system from ERL Automation for the modernization of its prefabrication. The cutting system has been in use at the steel prefabrication and processing expert since the beginning of 2019 and has since taken over almost all beveling work. This has enabled the company to significantly reduce production times and at the same time improve cutting results.
Weber Stahl-Anarbeitungs-Service-GmbH, based in Großlittgen in the Eifel region, was originally founded in 1984 as a smith's shop. Today, the company employs around 120 people and offers a wide range of services related to the processing of steel, in particular high-strength fine-grained structural steel. These include precision cutting to shape as well as edging, chamfering, welding, machining, straightening, rolling, steel shot blasting and surface coating of components. In addition, the production of complete assemblies and in-house developments are now also part of Weber Stahl's range of services.
In order to further expand its competitiveness, those responsible at Weber Stahl have been toying with the idea of modernizing weld seam preparation for some time now. At the beginning of 2018, the company took the decision to put its plans into action. This had become necessary because the two robot cutting systems previously used could no longer fully meet the requirements due to their age. Weber took a close look at possible cutting systems and finally chose the BIBER robot cutting system. "We had been following the developments with the BIBER with interest for some time, and after a reference visit to a large German crane manufacturer who had been using a similar system for years, the decision was made," reports Managing Director Florian Weber. "The excellent cutting results and short production times convinced us."
Flexible system required
Weber Stahl counts companies from a wide variety of industries among its customers, and the orders are correspondingly diverse. For weld seam preparation, this means that a wide range of bevels must be processed, whether for simple or complex components, individual parts, small batches or large series.
The BIBER robot cutting system from ERL Automation is the optimal solution for this. The cutting system is suitable for creating almost any type of bevel. Whether simple bevels, double bevels, bevels with or without a bridge - the BIBER can be used to apply a wide variety of bevels to parts that have already been shape-cut. For cuts from above, bevel angles from 30° to 90° are possible, and for cuts from the front between 15° and 89°, assuming accessibility for the torch.
The new system at Weber is designed for sheet formats up to 2,000 × 9,000 mm. This large working area is made possible by the fact that a cutting robot is mounted on an upstream console and can be moved on a linear unit around 10 m long. The company can use the cutting table with integrated suction system in its entire size, for example for very large components. It is also possible to divide the table into two cutting areas, each measuring 2,000 × 3,000 mm, for smaller workpieces using a movable partition wall system. The advantage of this is that the robot and the system operator can work simultaneously – while the robot is chamfering components on one side of the partition wall, the operator can unload the finished components on the other side alongside and reload the table. This way, the system can be optimally utilized. The operating personnel are always protected, as light barriers reliably safeguard the respective cutting area.
Time savings in several respects
The cutting system is equipped with a Kuka KR60L30 robot, whose HA (high accuracy) design is matched to high-precision cutting tasks. In combination with modern plasma cutting technology, a HiFocus 440i power source with an automatic gas console, cutting lengths of up to 60 mm are possible. For oxy-fuel cutting up to 200 mm, a robust machine torch with internal ignition is available, which scores with a short preheating time and high cutting speed. A line laser scanner mounted directly next to the torch measures the relevant component before each cutting process and automatically compensates for any tolerances from the pre-processes. The interaction of modern cutting technology and the latest laser technology results in highly precise cutting results and, due to the elimination of reworking, in not inconsiderable time savings.
A special feature of the Weber Stahl system is that component measurement can also be deliberately skipped, so the system does not check every component to see whether there are any deviations from previous processes. This way, production times can be significantly reduced once again, but this is only effective if there is certainty that the pre-process is correct. "It often happens that we have to bevel workpieces cut by laser in high quantities. Due to the process, in these cases we can dispense with measuring each individual component and benefit from the function provided especially for us," explains Peter Rehm, operations manager at Weber Stahl.
Another aspect that has a positive effect on the time factor is a special tool holder that allows plasma and oxy-fuel torches to be replaced within a few minutes. The torches only have to be detached from their respective positions by a screw connection, replaced and reattached at the new position. Plug-in connections are available for the cable and signal lines. Automatic torch calibration via measured stop systems in the torch holder ensures the correct Tool Center Point (TCP).
"The BIBER has already provided a considerable leap in performance. Compared to our previous chamfering robots, we produce many times faster with the BIBER," states Rehm. The BIBER programming software has played its part in this. It was developed by ERL Automation specifically for this type of system, with the aim of making the realization of complex bevels as simple and efficient as possible for the user. Accordingly, cutting programs can be created from .dxf files in just five steps. After the .dxf file has been loaded from the directory, the component is roughly positioned on the virtual cutting table. Then, with just a few clicks, the bevels are defined before the appropriate parameters are selected from the database and the robot program can start.
Sophisticated operating concept
Efficiency is also a top priority when it comes to operating the robot cutting system, which is why it is equipped with numerous useful features. One example is the camera system intelliplace, which automatically detects table occupancy via a high-performance camera, compares it with the manually selected cutting programs, and automatically assigns them correctly. This reduces the work steps for the operating personnel and minimizes possible sources of error. In addition, users have access to an integrated process database with cutting parameters for oxy-fuel and plasma cutting. The most important cutting data sets, which are based on ERL's many years of experience, are stored ready to start and can be expanded as required.
The system is controlled from a control centre. In the semi-open, soundproofed cabin, operators are protected from noise pollution, but still have a constant view of what is happening through windows with glare protection and can follow the processes. For safety reasons, a protective fence surrounds the system. Access is protected by light barriers, so that in the event of any unauthorized entry, the process is interrupted and the robot stops. Crane monitoring is also integrated at Weber so that the system also stops if one or more cranes come too close to the robot's working area.
The BIBER robot cutting system has now been in operation at Weber Stahl for just under half a year and the verdict is thoroughly positive. "The system concept is optimally adapted to our cutting tasks. We can cut a wide variety of bevels - and do it better and faster than before. This puts us in a very good position for the future," Weber sums up.



