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Old 10-02-2006, 07:02 PM
  #23  
da Rock
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Default RE: In flight CA hinge failure...

It's really interesting that the hinges failed after only three flights. Never seen any that failed that quickly.

It appears that at least some of the CA hinges that fail were not installed in slots that were straight along the hinge line. If the slot isn't cut in line with the surface the hinge can't easily flex along just a simple fold. It'll stress from each side. I've seen a number of prehinged "you get what you pay for" models that had hinge failure and two things were common in each case. There was at least one hinge that wasn't in line, and the hinge material was the naked or slick plastic. They weren't the layered CA hinges that have wicking material on both sides.

I would hazard a guess that either one of the outboard hinges was not in line or had been nicked. Some plastics will tear easily if given a starting place for the tear.

I also wonder if some of the plastic used might not be weaker in one direction and more likely to tear across than lengthwise (or vice versa).