You're a braver man than I.  But then it's not the cautious folk who advance the state of the art, is it?

  I'm a big fan of titanium in hard-to-reach areas, and would probably go with that if it's feasible (I don't know how it works for bearings).  Sure, it's a few times the cost of stainless, but the price delta compared to the overall boat cost should be minor.  Particularly if you're going with a single mast because the wing allows you to cut down on sail area.

  How about mounting the metal bearings inside a UHMPE bearing?  You'd have to replace the plastic every now and then, but that's the inexpensive part, and it's highly unlikely that both sets of bearings would fail at the same time.  Or you could go with metal on the outside if that makes it easier to replace the plastic.

  Isn't polyethylene grand?  Given the flimsy PE tarps of the 1970's, would would have thought the chemistry would advance to where we can make UHMPE bearings and spectra/dyneema halyards and sails that are near impervious to UV rays?

        - Mike

 

Talador "<<However if the system is not free to rotate (frozen or sticky bearings)  then yes you have a nightmare situation.>>


 Mike,  "Definitely.  And then what?  With a soft sail, you could probably just drop the sail, or if that doesn't work, cut the halyard or even climb the mast and cut the sail with a knife (scary, but theoretically possible).  With a rigid wing there isn't really any recourse."

I have designed the wing to fold with a hinge just above the  stub.  At an apx. weight of 300 lbs with the aid of a rod I should be able to lower the wing and secure it.  Then the bearing can be replaced etc. It is probably a two man job, but better than needing a crane.

Talador

My design problem is that I keep going between machined metal bearings and UHMWPE  each has some definite pros and cons.  The main problem with the machined bearings is the tolerance and flexing (binding) issues.  The UHMWPE won't rotate as easily (sticky) and suffers from creep over time. . .  Might have use lubricated phenolics.