They provide valuable support with their precision, flexibility and speed: KUKA robots are helping to restore historic sculptures at the Canadian parliament building in Ottawa, as well as building the sixth Messner Mountain Museum on the summit of the Kronplatz (Plan de Corones) in South Tyrol.
This involves them completing up to 95 percent of the preparatory milling of sandstone, and creating negative molds from extremely hard polystyrene. About 4,700 sculptures for the Canadian parliament building and something like 400 concrete components for the museum have to be made.
KUKA robot restores sculptures in the Canadian Parliament building
The three neo-Gothic buildings of the Canadian Parliament in Ottawa are built on an abrupt slope on the banks of the Ottawa River in the city center. All three of the buildings will be renovated over the course of the next ten years.
Tests are currently being conducted to determine how digital fabrication can assist in the reconstruction of eroding sculptures. A sandstone sculpture on the facade of the East Block was selected for this purpose. The relief features an owl amongst thistles, carved into a 1725 mm x 1120 mm slab of Berea sandstone.
Instead of using the normal plaster casting process for the copy of the sculpture, the relief was digitized. The digital model was used to mill a copy of the sculpture from highly compressed polyurethane foam using a 3-axis CNC milling machine.
The damaged areas of the sculpture were then rebuilt by a sculptor with modeling clay and digitized once again. Using this second digital model, a KUKA KR 120 R2700 robot milled a series of test pieces.
This allowed the appropriate milling parameters to be determined, after which the definitive relief was milled from sandstone. The robot machined the sandstone down to 1.5 mm proud of the digital model. A sculptor then applied the finishing touches to the remaining 1.5 mm. The application comes from integration company, New Age Robotics.
There are approximately 4,500 sculptures inside and outside the Parliament, and many of them require restoration just like the “Owl and Thistle” relief. In addition, there are 200 sculptures that have yet to be formed.
KUKA robot mills formwork elements for concrete components
At an altitude of 2,275 meters, the sixth Messner Mountain Museum is being built on the Kronplatz mountain in South Tyrol. To round off the mountain museum project by Reinhold Messner, it will house exhibits dealing with the topics of “rock” and “the life of mountaineers”. The construction phase of the building project planned by the architect Zaha Hadid started in mid-2013. The opening ceremony is planned for summer 2015. B & T Bau & Technologie GmbH, based in Raubling, Germany is turning the unusual architectural ideas into reality.
When the KUKA robot of type KR 210 L150-2 starts to process the polystyrene blocks, they have already been cut into the general shape. Working precisely and flexibly, it supports the 15 people working on the new major project. About 400 formwork elements are being created from polystyrene with a hardness of 200 kilopascals.
“By using the robot, we can implement the individual requirements to be met by the museum’s architecture very effectively, and produce even the most complicated shapes,” says Stephan Thaleck, CEO of B & T Bau & Technologie GmbH, giving an insight into how the major project is being carried out.
Once the polystyrene molds are finished, they are cast using special concrete. The result: extremely thin, lightweight but also sturdy components made of concrete. These can be assembled like a jigsaw puzzle to create the final curving shape, such as an outer cheek of the balcony balustrade. “The great advantage is that the robot can be used highly flexibly – above all when milling work has to be carried out at height,” says Thaleck, describing one advantage of using the robot.
The surface is finished by hand until the perfect surface quality has been achieved. A large proportion of the polystyrene molds used are shredded in order to be reused later. “This means we can manufacture the concrete components very efficiently in terms of raw materials,” declares Thaleck.