Tune
Aha,
I had forgotten that it was an aft-lowers-only rig, though this makes sense with swept-back spreaders; rigs like this with forward lowers -- and they exist -- end up with overloaded aft lowers.
In your case, it appeared that the sweep on the spreaders was less than planned, because the forward edge was what was being crushed, right? If that's the case, it might be because the upper shroud chainplates were too far forward. And if so, that would mean the the spreaders were exerting less forward push than planned, and that in turn would mean that the aft lowers meet with too little resistance. Result: with any kind of tune on those lowers, the mast inverts.
I recently struggled with this on a friend's Halberg 34, and ended up keeping the lowers slacker than I liked, in order to keep the mast right. Seems to be working.
Anyway, another possibility is that the spreader base is simply cut at the wrong angle, and/or that the tenon is positioned incorrectly, and/or that the primitive bases are going to give you grief regardless. In any event, if you aren't going to move the upper shroud chainplates, then you need to get the spreaders to line up with their bases, for fixed-position spreaders, or fabricate swinging spreaders, which is a whole other can of variables.
What diameter wire are we dealing with here? The numbers on the sketch would be right for 3/16".
Fair leads,
Brion Toss
|