How do Olympic bobsled champions transfer the proven speed of hand-made blades into a new standardized material mandated by the sport’s governing body?
Team Kiriasis, Germany’s top two-person woman’s bobsled team and world champions, developed a partnership proposal that includes from Renishaw (www.renishaw.com), Siemens (www.siemens.com), Sescoi (www.sescoi.com) and Iscar (www.iscar.com) to move blade manufacturing from art to science.
Renishaw used its latest measurement technologies, including its REVO ultra-high-speed measuring head for coordinate measuring machines (CMMs), to deliver precise data capture of the legacy blade geometry that had carried the team to a world championship in 2005 and Olympic gold at Turin in 2006.
Success at blade replication won Team Kiriasis the 2006 and 2007 Federation Internationale de Bobsleigh et de Togogganing (FIBT) World Cup and World Championships. In fact, running the new blades, the team won the world championship by more than 2 seconds, the biggest margin ever recorded in championship history in a sport in which races usually are decided by hundredths of a second.
After taking the gold medal at the FIBT championships in St. Moritz, Switzerland, with brakeman Romy Losch, driver and team captain Sandra Kiriasis told television broadcasters that the blades were the secret of her success.
Renishaw exhibited her bobsled at the EMO machine tool show last September in Hannover, Germany.
Team Kiriasis’ success highlights the impact that engineering technologies can have at the highest levels of competitive speed sports, Rainer Lotz, managing director of Renishaw GmbH, said.
“We know about the small margins between success and failure at the highest levels of international sports. Renishaw already is making significant technical contributions in the world of international motorsport, such as F1 and NASCAR racing, both in engine manufacture and on-car monitoring systems. We have been delighted to add our measurement expertise to the Team Kiriasis blade projects and look forward to contributing to Sandra’s continuing success.”
The blade project arose following new rules introduced by the FIBT in October, 2006. The new rules aimed to remove on-going disputes over the use of various materials and treatments in blade manufacture. All bobsled teams now must use the same specification steel with creativity allowed only in blade form.
Kiriasis prized the competitive edge achieved by her existing blades, but they created them using manual techniques, and there were no drawings or electronic CAD data that would have allowed them to be re-manufactured with the new standard specification steel.
The first step by the Renishaw- Siemens-Sescoi-Iscar partnership was to send the existing blades to Renishaw’s U.K. research facility where Renishaw used its REVO five-axis measuring head to scan the blades and to capture data points that allowed it to define the blades’ geometries in exact mathematical detail.
The company said the low-mass REVO head combines horizontal and vertical rotary axes to perform highspeed “infinite” positioning of its touch probe at speeds to 500 mm/sec and to capture of 4,000 data points/ sec compared with 200 to 300 data points for conventional scanning.
Once the blade geometry data was captured, both DXF and IGES files were created and sent electronically to Sescoi, a software specialist for tool and mold making.
Sescoi created a CAD/CAM program for a Siemens Sinumerik 840D CNC control and ShopMill HMI that was fitted to a DMG CNC milling machine located at tooling manufacturer Iscar Germany.
The companies said in a joint statement that the number of data points to work with enabled high geometric and contouring accuracy as well as smooth surfaces. The finishing program for the runner surfaces was 5MB and contained about 100,000 lines, producing surfaces almost as polished as a mirror.
Following machining, the finished blades were checked for form while with the Renishaw OMP400 touch probe they were still fixtured on the machine tool. A patented strain gauge sensing mechanism and advanced electronics allow lower, highly consistent contact forces with reduced pre-travel, to enable sub-micron 3D probe measurement and verification of the contoured surfaces.
Sandra Kiriasis personally evaluated the machining and said she received runners machined to exactly the same geometry as her championship-winning blades.
With the new blades mounted to her sled, she said they performed as well as or better than the old blades, continuing her edge over world-class competition.