The heavy-duty robot KR titan at Rosenbauer

A huge heavy-duty robot, a state-of-the-art machining centre, a custom automation solution: How fire brigade supplier Rosenbauer has joined forces with Kuka, Promot and Hermle to make its production fit for the future.

In its narrow enclosure, the gigantic robot seems almost even more enormous. Surrounded by a pallet pool, the KR titan picks up individual clamping pallets with components, feeds them into the connected milling-turning machining centre, and retrieves the finished parts. For example, highly complex pump parts or chassis parts are machined here. In between, the KR titan independently rearranges the pallets in the sequence that suits it best. Despite its enormous size, this all happens surprisingly quickly and quietly. And it happens completely autonomously: The robot in the production area of Rosenbauer, the Leonding-based fire brigade supplier, works when the people have already left. The fact that the plant has been running smoothly for a few weeks now is thanks to the perfect cooperation of several companies.

Big plans, little space

A milling-turning machine had previously stood in the same place. There was no alternative to replacing it, explains Michael Schöftner, head of mechanical production at Rosenbauer. After 14 years, more and more “aches and pains” had appeared and the repairs increased. “We were also maxed out in terms of utilisation and productivity, which in my mind necessitated the possibility of an unmanned third shift. At the same time, our component spectrum has expanded, especially to include chassis parts that were difficult to produce on the old machine.”

Outsourcing production was not an option: Many of the complex parts are absolute know-how carriers, and Rosenbauer cannot afford to outsource their manufacture. On the contrary: Components of the new RT series of emergency vehicles were added, and other parts that had previously been processed externally due to their size were now to be brought in-house.
From the beginning it was clear that there would be a space problem: The maximum footprint of around six by six metres stood in the way of the plans that were growing larger and larger in Michael Schöftner’s mind: He wanted a machine that could handle large components smoothly, and he wanted the automated combination with a robot and a pallet pool of 15 clamping pallets in two different sizes to enable the unmanned third shift. So the shopping list got successively longer.

The new heart of production

The decision in favour of a Hermle milling-turning machine was made relatively quickly. “I’d wanted a Hermle for ten years,” says Michael Schöftner, “the size and type are custom-made for our applications.” In addition, there was positive feedback from supplier companies that encouraged him in his choice.
In the end, it was a C52U-MT, a machining centre that can process components up to a size of 1000 x 1100 x 750 mm and, according to Schöftner, ensures “enormous dimensional accuracy and surface quality”.

The machine is equipped with a tool spindle with 14,000 rpm, a tool magazine with 302 tools with HSK100 mounting, an internal coolant supply, which brings the cooling lubricant from 10-80 bar continuously programmable to the application, measuring probes as well as form control from Blum. Furthermore, there is the Hermle information monitoring software system for constant communication and request of all machine statuses.

Michael Schöftner spent a great deal of time arguing the case for the biggest-ever investment in mechanical production to the Rosenbauer executive board. He filled several folders with ROI and business case calculations, itemising each component. And finally got the go-ahead for the custom automation system.

A system like the one I envisioned didn't exist before, especially not on such severely limited space. So I took the liberty of designing a custom-made automation system for us myself.

Michael Schöftner, Head of Mechanical Production at Rosenbauer

A titan in the children's room

For now it was time for automation. The way he did it has the potential to become a little Rosenbauer legend: Together with his son, an “enthusiastic Lego technology builder”, he sat down in the children’s room and made a design out of Lego, a Kuka robot model and a few small pallets, which became the basis for the first sketches. And which is amazingly close to the actual implementation.
It was also clear relatively quickly that it would be a Kuka robot. In his search for a robot that could move pallets weighing up to 900 kilograms in a confined space and at the same time have a reach of several meters, Michael Schöftner very soon ended up at the KR titan, Kuka’s largest model. The KR titan 1000 is the first six-axis heavy-duty robot with open kinematics and payloads of up to 1,300 kg.

Not off the shelf

The next path led Schöftner to the specialists at Promot. In this case, there was a common history; Rosenbauer had already come to appreciate the Upper Austrians’ individual solutions in several projects. An “off-the-shelf” automation solution was not an alternative in view of the complicated requirements. After several coordination meetings with Hermle, Kuka and Promot, the solution that is now in operation in Leonding was finally developed.

The focus is on the Kuka KR 1000 titan in the six-axis standard version. Due to the pallet size, the heavy-duty robot has a payload of “only” 850 kilograms and a reach of up to 4 meters. The giant is thus the central transport element of the Promot Palmaster, in which up to 15 pallets can be stored temporarily. And – this was an essential criterion – pallets in two different sizes. The third element in the ensemble is the Hermle C52-UMT. The parts clamped on pallets are fed to the Palmaster via the set-up station. The KR titan receives them and passes them on to the machining centre, making full use of its long reach. Once processing is complete, the robot picks up the pallet again and takes it to be set up, changed over or removed. So, depending on the priority, it fetches the components again and again, has them processed in the machine and puts them down again.

All processes are controlled by the master computer software Prosys 3.1, a longstanding in-house development by Promot. In addition to the sequences, the software also manages all NC programmes, calculates machine utilisation as well as tool balances and manages the clamping devices in the system. “In the third shift,” says Michael Schöftner, “it is now really possible to operate unmanned. This ensures peak coverage, and we can cushion bottlenecks in the assembly line very well. I didn’t have to convince anyone about automation and robotics per se, but the scale was of course considerable. The fact that the company has trusted me to invest this amount of money is anything but a given.”

Cooperation between Rosenbauer, KUKA, Hermle and Promot

Work in progress

Michael Schöftner emphasises that the possibilities of the plant, the robot and the machine are currently far from being fully utilised, “but we also want to be prepared for the future.” And of course there is still work to be done in other areas. Schöftner currently has two more projects in mind, “and I will of course be contacting the same people again.”