Daniel Collins wrote:

I haven't spread the entire thing out yet (nervous!!! I hope the luff is actually straight!!) but that should happen tomorrow.  Cross your fingers for me!  

When I made my (cambered, fanned) sail for Fantail, I was horrified when I stretched it out.  The luff looked like a dog's hindleg!!  Used as I was to building flat sails, I couldn't believe it.  Now whether this was as a result of my sewing or of the design I don't know, but I know the panels were accurately cut and carefully sewn.  But once the sail was bent on the problem disappeared.  Soooo if your luff is less than straight Don't Panic!

Daniel Collins wrote:

David Tyler wrote:

Daniel Collins wrote:

Ok, another detail question: for the batten pocket ends, in what order should I sew tabling, pockets, end patches?  I'm at that stage now and rather confused about the right way to do this...

One other question: should I be cutting Odyssey III with a hot knife?  The acrylic backing seems to be holding fine when I use regular scissors.... but it occurred to me halfway through that I should check.

AND.... relatedly,

Do I need to fold over the edges of the batten pockets - will they unravel under load or is a straight cut ok here without any edge treatment?

Thanks everyone for the great ideas and postings.. this thread has been beyond helpful!

Patches first (smallest first, then going larger, stitching the inner edges of each, but leaving the outer edge (coinciding with the edge of the sail) to be sewn with the tabling. Then tabling. Then pockets last, because if anything is going to chafe and need replacing, it's the pockets.

David Tyler wrote:

Daniel Collins wrote:David, 

Regarding tabling, do you mean to say that I can effectively cut the sail exactly to the edge and just wrap the tabling around (4" to one side, 8" to the other) and that's sufficient?

Or should I also turn the edge of the sailcloth under 1" and sew the tabling entirely to a single side?

Daniel,

The first way is the easiest and best, and is quite sufficient. The second way is a throw-back to the way they used to do things with Egyptian cotton cloth. I guess you could do it that way, but I can't think of a good reason for doing so, unless it's to avoid turning the sail over to be able to sew down the edge. I can, however, see a difficulty in sewing down the edge of the 4" side, when it should be inside the 8" side. You would have to do it by feel and guesswork.

Yes, it makes much more sense to do it the first way.

Daniel Collins wrote:David, 

Regarding tabling, do you mean to say that I can effectively cut the sail exactly to the edge and just wrap the tabling around (4" to one side, 8" to the other) and that's sufficient?

Or should I also turn the edge of the sailcloth under 1" and sew the tabling entirely to a single side?

The first way is the easiest and best, and is quite sufficient. The second way is a throw-back to the way they used to do things with Egyptian cotton cloth. I guess you could do it that way, but I can't think of a good reason for doing so, unless it's to avoid turning the sail over to be able to sew down the edge. I can, however, see a difficulty in sewing down the edge of the 4" side, when it should be inside the 8" side. You would have to do it by feel and guesswork.

Kurt Jon Ulmer wrote:

Hi Daniel,

If I read your Ps, Us and Bs correctly, you have only one batten ending near the yard at the throat, as in mehitabel's sails. And all battens are the same length. Both right?

And you've raised the angle of the four battens under the yard and left the bottom 3 parallel. Evidently.

You only mention one value for P, so your panels are all the same height at the luff. Yes?

mehitabel has her P varying up the luff (from the bottom: P-~2"; P; P+~2"; P+U; P+U; U at the yard.) 

- It's so that reefs are smallest to begin with, 'balancing reefs' as I mentioned in the article...

- And so that we can use 3-point sheet spans without raising the whole sail farther off the deck to provide the necessary sheet drift, Dmin.

So your sails differ from mehitabel's in these ways:

- higher aspect ratio

- one batten more

- incorporating more 'fanning' of the upper spars

- P at luff same for all panels.

Does that seem correct?

Indeed it does.

Forgive me for reminding you that you must check each panel for the batten stagger it creates, using compass and all, as in Figure 6.35 and relevant text in PJR. On mehitabel the stagger isn't overly-generous but is enough. 

Yes, Tad did that when coming up with the plan.

You're using higher batten angles than I did, and you must check not only batten stagger, but also where your deeply-reefed and furled sail will end up. This part of the design can take you way back to calculating the rise above horizontal (pp. 100-102) and for me there was no easier way than iteration, to make sure I wasn't wrecking something by changing Ps and batten angles. Numbers have to be flexible while you're doing the geometry.

Provided you do/did that homework with rigour, I think you'll end up with great sails.

Cheers,

Kurt

To my knowledge all of these things were checked carefully by Tad before the plan was put together - he's done a number of junk sails before and we corresponded about a variety of options before settling on this one, so I'm quite hopeful this goes together well.