Hi Greg -
There were some problems recently when a tail hit the blades which brought some doubt about the furling stops being strong enough (and in the future Ill make those stronger) - but I really believe the bending that happened there was due to collision with the blades, because I've not seen that problem on any other machines, even larger ones with smaller tail pivots (like mine).
The plywood blade hub, with 5 studs through it - and the wooden blades are not a problem yet. Even in Scotts, after the tips hit the tail, the hub and the area where it attached to the alternator was fine.
We did an interesting experiment with Scotts last weekend. He's working on a new 11' blade set to replace those that got wiped out by his tail, but in the mean time we decided to try sticking a 11' diameter 2 blade prop of an old wincharger on it. Folks worry about wooden blades... this 2 blade prop is of cedar and it's around 60 - 70 years old! Of course, the thing shakes rather violently in while yawing, as we'd expect from a 2 blade prop.. so it's gotta come off. Otherwise, it works fine.
I think most homebrew systems have a weak link, most of those I've found have been posted here - usually simple mechanical things. I don't think it's hard to build a fairly reliable system though.
