At the Swiss Science Center Technorama, 500 experimental stations offer visitors the chance to experience phenomena from nature and technology up close. The design team from Winterthur worked with BIBUS AG and ACE Stoßdämpfer GmbH to find the most suitable damping at the pivot point for a large seesaw that allows visitors to experience the leverage forces directly.

Technorama: experiencing natural and technological phenomena first-hand in Winterthur

Located in the north of Switzerland, Winterthur is the sixth largest city in the country with over 100,000 inhabitants. As the second largest in the canton of Zurich, Winterthur used to be an important industrial location and is now known far beyond the country's borders as a service, educational, cultural and leisure center with its 16 museums. The Swiss Science Center Technorama plays a special role here. This museum enables direct experience with hundreds of phenomena from nature and technology, as visitors are invited to lend a hand at the experimental stations, experience natural phenomena with all their senses and manipulate exhibits in order to literally understand the world. You can touch, play with and experiment with everything at Technorama. Touching is therefore expressly encouraged in this museum, and learning in the Science Center takes place through play, whether indoors or outdoors, in good or bad weather. The Swiss society Pro Technorama, the patrons' association of this Science Center, counts more than 300,000 visitors a year and is proud to have more than half of all museum visitors in the city of Winterthur. In the Science Center itself, a motivated team of well over 100 people has been stimulating curiosity and enthusiasm for science and technology with a constant stream of new exhibits and laboratories since 1982.


Exhibit makes leverage forces tangible in the fresh air

"It's the mixture that makes the attraction. In addition to interactive exhibitions on natural phenomena, there are spectacular presentations, demonstrations and an exciting range of workshops on biology, chemistry and physics. In a total of seven laboratories, you can experiment independently with expert support and, depending on the season, let off steam before or after in our indoor and outdoor areas," explains Juliana Campos, Head of Communication and Marketing at Technorama. The latter is possible in the summer months, for example, at an exhibit where visitors can literally sit on the longer lever. This is a special construction of a seesaw on which one person can lift up to three others, even if they are much heavier together. In order to experience the forces first-hand, the person on the longer lever can pull a seat plate that can be moved three meters to the correct position and then keep one, two or even three opponents sitting on the shorter lever, who may be heavier, in balance or higher up in check. As this is often more lively than in a laboratory or classroom, the team led by workshop manager Jürg Oppliger endeavored to design this exhibit to be as safe and durable as possible. The first thing that catches the eye in the drawing (Fig. 1) is the solid beams and the delicate yet robust lattice structure of the lever arms. As an employee of the Technorama workshop and designer of the seesaw, Simon Michel provided hydraulic industrial shock absorbers at its pivot point during one of the planning phases to directly decelerate the forces acting on the two beams of different lengths. He also added a solid-state damper as a safety element for the stop (Fig. 2), so that both the ends of the rocker and the rocker itself would survive the wildest lifting experiments undamaged.

Giving the rocker the right damper

Simon Michel reports on the testing phase of the exhibit, during which the technicians initially equipped the construction at the pivot points exclusively with solid-state dampers. These turned out to be inadequate in terms of the measured damping, which was mainly manifested by rocking. "As a result, we noticed excessive torques at the supports in the end position and then decided to improve the damping to make the ride experience smoother for visitors and more sustainable for our design," he recalls. The fact that the hydraulic industrial shock absorbers still shown in the design drawing were not used in Winterthur is thanks to the damping experts at BIBUS AG, who Simon Michel called in after researching the Internet.

The Swiss BIBUS Group is known as a supplier of hydraulic and pneumatic drive and control systems as well as complete systems. The company from Fehraltorf in the Zurich Oberland also sells hydraulic and pneumatic components from well-known suppliers and offers these for special machines or special designs, such as in the case of the Swiss Science Center Technorama, in any quantity, even small quantities. For industrial shock absorbers and similar components, the company has been relying on solutions from ACE Stoßdämpfer GmbH in Germany for decades. Michael Weber, team leader of the damping technology department at BIBUS AG, and his colleagues from ACE's technical sales department in Langenfeld always work closely together. In this case, Christoph Berning from technical sales at ACE was consulted. He recalls: "We find this application very appealing because it allows the target group of children and young people in particular to explore the laws of leverage in a playful way. Compared to our other daily work, this application was also unconventional in terms of the design of the damping elements." This is mainly due to the special feature already briefly mentioned that the design has three seats with a short lever arm on one side and one seat with a long lever arm on the other, whereby the distance between them can still be adjusted in order to lengthen or shorten the lever arms. This made it difficult to calculate the exact damping at the pivot points because there were too many variables. So a team meeting was held without further ado, during which Simon Michel from the Science Center and the ACE-BIBUS duo Berning-Weber discussed various damping options and which effect should best be achieved by the damping. The team came to the conclusion that a certain amount of damping and thus a major part of the energy dissipation should be achieved in order to protect the construction, but at the same time enough energy should still be retained in the system to enable the bobbing experience and maintain the fun factor.