Tuesday, November 26, 2013

Interesting comments from Bill Hansen

http://www.kiteforum.com/viewtopic.php?f=1&t=2382668&start=10

Interesting comments from Bill Hansen :

I cannot comment on what other brands do, have or haven't done. I either no longer work for them or never did so I simply do not know. Surely Switch are not the first to do some level of failure analysis. Some products like paragliders require certification and the factories who make them have dedicated testing facilities. Some also make kites for most popular brands. I have personally been involved in this regard and can honestly say the extent and expertise of the testing varied greatly from extremely competent to rudimentary. What I can say is the technical level and extent of testing at Switch Labs is refreshing. It shows the sort of independent planning, resource dedication and engineering to be the market leader.

What are we or have we tested?
1) Components - Switch bar components are designed in-house in NZ and manufactured exclusively for Switch. They are stress tested to failure and repetitively under higher working loads for wear and degradation. We want to know exactly when and where failures might occur. Simply actuating a quick release on the beach is an irrelevant test when the forces might far exceed your weight.
2) Fabric - Switch works with several fabric suppliers and is constantly searching for new ones. They are happy to charge us for new test fabrics and even provide numbers for weight, tear, puncture, elongation, elasticity, UV resistance, etc. However, we have found that our own sophisticated in-house testing with consistent procedures, allows us to directly compare them with confidence. With our test numbers, when we make a kite out of new fabric that performs differently, we then know exactly why by checking our test data. Example: if reduced or increased stretch is changing the dynamic shape, we can adjust our patterns to compensate (or reject or change the fabric accordingly.)
3) Construction - In sail and kite production, proven construction is mostly from experience as to what does or doesn't work. Most modern-day kites adhere to these tried and true ways. We can and do build test kites and send them out for abusive testing by team riders. But, our lab testing shows conclusively what is strong and what is not. We have found profound differences in seam strength related to stitch type and width, substrate gluing procedures, reinforcements and thread type which would be unobvious to the casual observer and unlikely to show quickly (or even after a year) in a test kite. Sometimes removing a bar tack or switching from 3-step to two rows of 1-step zig-zag makes a huge difference in failure and the forces required to cause it. Some constructions may prove to be OK but a slight change may make them 'bombproof.' Our lab testing actually shows the difference so we can make it so.

Future Switch Labs projects - real world numbers for bar pressure, sheeting/steering loads, real and apparent wind velocity, total force, lift vs drag, VMG, turning speed, etc.
Exciting isn't it?

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