NOHUHU wrote:
I think your jib frame and furling setup is brilliant, Jim. Tight integration.
To recap - are you using any stays?
How would you describe the forces at different points of sail? What direction and energies are exerted?
I'd like to explore this mod for the AI a little further, if you don't mind.
Thanks NOHUHU,
I have used stays but never for this particular configuration. I rigged some up 2 days before the race but just before leaving I had a change of mind and removed them. They are kind of a security blanket but I'm not sure how effective they really are. On the beach I asked Jim from Hobie about them and he was more concerned about supporting the mast with a rear stay than side stays. Kind of like the way Bob does his (FusionEng). I was surprised to hear this since Jim's earlier jib on the TI incorporated side stays. Although his side stays were somewhat behind the mast and provided some rear support. In the EC, I noticed Jim's spinnaker had a rear stay but the way it deployed from the top of his mast would always be hitting the mainsail. I imagine that was quite annoying for him during the race. Wish he would comment here and share how that went for him. Especially when the wind was flipping the mainsail from side to side all the time.
The problem with the AI/TI and rear stays is how to extend your mast topper to keep the stays from hitting the mainsail. I started to fabricate a mast topper like Bob's but wasn't comfortable with the weight of his design. He has a really slick setup on his TI but I felt that mast topper was too heavy for me and would make demasting at sea almost impossible. And it seems to me that extra weight on top adds more to the mast stress. I needed a jib design that allowed easy demasting at sea to get under bridges.
I am not an engineer and really don't know what I'm talking about, but feel a TI with a jib may stress the mast holder more than the smaller AI sail. What happens in my setup is there is a good amount of downward pressure on the mast topper in most points of sail. I'll try to be more observant in the future though. The carbon fiber mast flexes pretty good when it's blowing with the jib exerting that downward pressure.
Sailing with a jib is a lot of fun. Especially when the design is simple and both sails furl and deploy easily. Of course there's always a risk of breaking the boat but it's a risk I accept and the more I use it, the less I worry about breaking the boat.
My latest plans include buying a TI and transfering this setup to the TI with some modifications. I'd like to add a bow sprint like Bob's and possibly a rear stay. I'm working on an idea for a lightweight method to modify my aluminum bearing topper with a rear stay extension.
But first I need to buy a reasonably priced TI. Anyone in Florida with a Papaya TI and trailer for sale ????