For the information of prospective sailmakers, IMHO using sail blocks is the way to go. Not exactly a new technology, but perhaps not that well understood. I’ve published an “international” edition of Larry Robinson’s “Sailmaking” booklet, and I mention a couple of pertinent points on one of my Web pages, at:
I’m delaying an order to Great Basin until he has copies. He said it will be about 2 weeks and he will put a note on his website. I wait impatiently.
Just wondering if htis booklet will be avaible on line also?
I hate ordering stuff and having to wait for it. Reminds me of Christmas all those nice presents and have to wait till everyone is at the house before we can open them.
thanks lester. i need some more of this here. no wonder the brits have a good hold on the tech side. but just hold on. here come soem canucks ,i hope
long live the cup and cris dickson
<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by Albertaclipper
Just wondering if htis booklet will be avaible on line also?<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>
It is a paper booklet only, I’m afraid…
Larry Robinson and I have been discussing sailmaking, and Larry has some valuable comments about the use of a sail block.
While much of the necessary draft to a sail is given by the outhaul, this is really only in the lower 1/3 to 1/2 of the sail. Above that, you can pull the outhaul out till there is no camber at all at the bottom and the camber of the top of the sail won’t change appreciably.
So there are two main reasons to sew in draft in a seam. One is to make adjustments to how the draft is distributed from head to foot, but the other is to put camber in the top half of the sail.
You need to be aware that, in addition to seam draft being a function of bevel angle and radius, the resulting sail camber is also influenced by adjacent seams. And, on a practical note, bevel angles above 8 degrees don’t work well, it is too difficult to get the seam wrinkle-free.
<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by Lester
And, on a practical note, bevel angles above 8 degrees don’t work well, it is too difficult to get the seam wrinkle-free.
AHHH! I think this gives me the missing link I was needing to understand this whole procedure. If the maximum practical bevel angle is 8 degrees then the radius is only changed to get more camber than 8 degrees will deliver.So when you are building blocks you pick a radius out of a hat and then figure the bevel angle. If it is more than 8 degrees then pick a smaller radius until the bavel angle is 8 or less. This explains why Larry’s bevel angles were always between 0-8 but the radii were all over the map.
By jove I think I’ve got it!
Am I right?