CNC helps windsurfers improve performance 8456

Friday, March 30, 2001

New Hyde Park, NY--A more efficient airfoil design combined with computerized manufacturing technology is helping professional windsurfer racers, such as Anders Bringdahl, improve their performance and win races.

According to George Klein, general manager at Techno-Isel (www.techno-isel.com), five of the top 10 windsurfers use boards designed by Gerhard Opel and his group. Opel has put his 14 years of experience as an aeronautical engineer to work designing rudders for windsurfing boards. And thanks to a Techno CNC router, the group produces fins to precise aerodynamic profiles at a cost that is cheaper than hand-production.

High-performance windsurfing boards normally operate in a planing condition with only the rear one-fourth to one-third of the board touching the water. A small fixed fin at the rear of the board operates to provide counterbalance.

While racing windsurfing fins have traditionally been designed by trial and error, it occurred to Opel that optimized airfoil designs that have been developed for aircraft could be transferred to sailboard fins with little or no modification. The problem in implementing this idea was how to produce these airfoil designs to the required high level of accuracy.

Fins for high-performance boards are traditionally produced by an experienced craftsman that builds a series of templates describing the fin's contours. The craftsman then uses these templates as guides in producing the final form with a hand grinder, which usually takes about a day. Moreover, the accuracy of manual production leaves much to be desired. It's necessary to test the fins in the water to determine whether or not they are effective, and typically top name competitors accept only two out of every 10 fins produced by these methods, according to Opel.

"When I originally developed the idea of building fins according to optimized aerodynamic profiles," Opel explains, "I assumed that it would be necessary to build them using conventional manual techniques. I knew we could achieve much greater accuracy with CNC machining, but I couldn't consider it seriously because I assumed it would be a $100,000 investment, which unfortunately couldn't be justified because the market for high-performance sail-board fins is just not large enough."

Then Opel discovered the Techno CNC router that starts at just $20,000. "Now it takes only 4 hours to produce each fin," explains Opel, "and I get better accuracy and part-to-part consistency than with the more expensive and time-consuming manual methods."