After reading Rolfs post on building his sails, I am considering designing and building my own sails. I am looking for resources on sail design. I am looking for suggestions on books, web pages, helpful sailors, anything to get me started.

I was looking at the following book:
Maximum Sail Power: The Complete Guide to Sails, Sail Technology, and Performance
http://www.amazon.com/gp/product/09...043319?s=books&v=glance&n=283155

My immediate concern is spinnaker design and construction techniques. Rolf said “gluing” is commonly used for spinnakers, I see that there is a chapter on molded sails, is that the same thing?

I have a background in high-performance aircraft (as does my crew). So that may help me in my design and optimization as well as allow for some innovation. It should be a decent hobby.

Matt
Fairport, NY

See: http://www.sailcut.com/

Matt,

Sail design is currently done using specific CAD software packages. The outputs of this is then fed a CNC cutter/plotter which is used to cut the panels. As far as assembly you have to glue and sew the panels together, add the batten pockets, bolt rope and then add the compression fittings with a hydrolic press.

So, what I'm getting at is this isnt a matter of buying a book and a sewing machine. The sail design software is expensive - as much as $15k, cutter/plotters are very expensive machines - no clue on the $$, but I wouldnt be surprised if they were 6 figures, and the hydrolic press is also an industrial type press - 6 ton I think to press the rings on the sail - again this isnt something you do at home with a hammer in the basement.

You might want to find someone to design your sails, and someone to cut them and start with the sewing and assembly part.

Keep in mind you need a pretty big space to put together a main.

Bill

Matt,

half my "sailing" bookshelf is filled with books about sailbuilding, design and sailmaking. If you are after one book, I would reccomend "The art and science of sails" by Tom Whidden and Micael Levitt.

Other books I think are good: "High performance sailing" by Frank Bethwaite and some of Marchaij's work (not directly about sail design, but lots of interesting material). The newest one looks promising, but I have not read it.

For a catamaran spi, I dont think you will find much literature. It's to new with to much development going on, and every sailmaker keeps his shapes to himself. But there are some pointers to what's fast and what's not. (flat, long luff, dont neccesarily use the whole foot length)

If you are interested, join the saildesign group at Yahoo and ask spesific questions there. If you want to, I can send you some Sailcut design files.

As for a sewing machine. I have buildt two mains, two jibs and a spi with my 30 years old Pfaff 362 (a domestic model). The Sailrite model with zig-zag and walking foot is just the thing if you can afford it. If not, there are lots of offers on ebay. Look for machines with a walking foot, zig-zag, a bit more power than a domestic machine and a large gate(arm). Metal machines are the best to sew with, and last very long. Myself, I am looking for a 70's Pfaff 1222 (or 1212, 1229 etc), becouse my machine lack a bit power and dont have a walking foot. If somebody see one, I would be grateful for tips (can't afford a Sailrite model)..

Laminated and glued sails are not the same. Laminated sails are buildt over a mould, fibres are glued to some kind of scrim (often mylar) and then lifted off the mould. Other 'laminated' sails are buildt just like cross-cut sails with mylar panels, then fiber reinforcement are added while the sail is laid on the floor (they fold the sail to make it lie flat).
Glued sails are just like panel sails, but instead of stitching all panels to each other you use glue.

Bill,

what you say is correct. I just want to tell you how we have solved the issues you mention.

There is one open-source saildesign CAD package available. It's not as advanced as other commercial solutions (check Autometrix's website for a demo of their advanced design package), but it get the job done. Sails are not rocket science, but to build great sails, you need to know what you are doing (not that I know it all..).

Sailcut can output manual cut sheets. With a large right angle, and a couple of measuring tapes, you can plot panels for a cross-cut sail quite well (we have). For a radial-cut sail, I talk with a sailmaker and buy the panels cut and marked from him. (I would definately go for a tri-radial cut in a spi). Sailcut can output DXF files, most cutting software can import.

For finishing off sails, we have used nylon webbing instead of stainless eyes. For the head, we used a standard stainless Sailrite eye installed with a hammer. Instead of letting this eye take all the load, we used a small shackle secured trough some webbing. The webbing distributes loads better than eyes, so you dont need to reinforce all corners as much.

We put togheter our sails in my living room. Will use the garage the next time I hope, as I have got the 'project' car out of it. Working on one part of the sail, and rolling it up as you go solve most space issues.

This picture show my 1.95m crew, Frode, aligning two panels for a crosscut mainsail in my living room. In the background you can see the bookshelf with my sailing literature and the cats basket. Not much room, but no problem either.




But you are right Bill, this is not for everybody. It demands a lot of work, initative, creativity and dedication. But it's not rocket science either.

Rolf,

Our public library actually has “The art and science of sails” book in it. I put a hold on it and will pick it up. I’m going to buy the Maximum Sail Power book as well. Between the two of them I should be able to get a pretty good idea.

I also put a hold on the book “Sailmaker’s Apprentice” which was well received by the amazon.com reviewers.

I would be very interested in viewing any files you would be willing to let me look at.

I designed a new jib and square top main for my boat, just playing around Saturday morning while trying to shake a hangover. One question, I could not figure out how to make the gaff angle greater than 90 degrees it keep showing the angle as 90 on the rendering. I wanted it to slope down like your square top does.

I joined the sailmakers group and will start reading the backlog once they let me in.

Matt

Bill,

Thanks for the warnings; my basement is plenty big for any beach cat sail. Like rolf said there are many places that will cut out a sail for me if I give them a file.

I would like to design my own sails; I may be able to get access to a program called “fluent” (fluid design) for optimization. My crew uses some sort of fluid design program at her work as well. I have to read up and figure out what they are doing now before I say anything else.

My current sail has a Head plate that is a sandwich of 2 metal plates with rivets through it. Probably bad for weight aloft, but it definitely works.

Matt

Matt,

you probably need to adjust your leech length if the gaff angle is too large. Remember that the shape you see in Sailcut isn't neccesarily the same as the flying shape. Use your judgement!

I dont like the headplate on square tops, it ruins the profile.
When you design jibs, remember to correct the jib for forestay sag, and match your luff curve to your mast bend characteristica.


All comments are appreciated..
tornado-jib-25-09-05.saildef
tornado-main-30-10-05.saildef
tornado-spi-27-11-05.saildef

The spi is just conceptual as of yet. I want to build a 1:10 model first to see the the flying shape. Hope to get to it during christmas..

Matt,
I'm glad I didnt scare you off, I've often thought about getting a sewing machine to make covers and tramps. Good luck.

Rolf,
Can you output something more generic? Like jpg or pdf?

Bill

Hi Matt,

I learned to make sails when I worked part time for a sailmaker in the early 80s. We were still hand designing and laying out sails, mostly crosscut, when I started. I was fortunate to work during the transition from dacron to mylar and from all hand layout to the methods already described in this string. Hand layout is an art and is easy after you have learned how and could easily and inexpensively be done at home. You could read some older books and experiment or find an old sailmaker and learn from him.

More likely it sounds like it will be easier for you to use computer software and get your designs cut for you. If you have that level of interest I suggest you try to get a part time job with a sailmaker to learn the business. If you stay interested, you may be able to be really useful to the sailmaker by sharing your software or improving their's. Many smaller sailmakers just buy generic sailmaking software and never learn how to "tweak" it to make it proprietary and differentiate their product. But the big advantage to any software is that when a design is good you can count on getting the same result time after time, unlike hand designed sails.

Most mylar sails can be glued together now using purpose built glue guns for a very robust seam without stitching and also very efficiently using benches that are about lower chest level. You can get the same result for lighter weight sails using double sided sticky tape (seam tape) which used to be used only to hold seams together until they were sewn. I have used that method very successfully on jibs, screachers, and very light mylar spinnakers. It would be good for A class main sails and maybe even heavier ones but I have not done that personally. For those lighter weight sails, I prefer using webbing for corners rather than metal grommets, both for weight savings and for ease of application. Just run a strip or two of webbing up one side of the corner and back down the other side leaving a loop on the corner to attach sheets or shackles to. Do that even if you have your sails built for you. Again, the exception might be for big mainsails that get really heavily loaded.

One last "trick" that you might find very useful, especially in your experimental phase. Cut sail designs out of paper and tape them together with the double sided sticky tape. Then set the paper sails on your boat and look at them (eyeball, camera, video, etc.) before committing yourself to some expensive mylar. You can make many sets of paper sails for the cost of one real sail and learn alot. Yes, they perform badly in strong wind, rain, etc. as you would expect so you do not try them in those conditions. They are just to see what a design would look like for real until you start to feel confident about what you see when you "fly" your sail designs on the computer.

On any design you are examining, it helps a lot to put draft stripe tape from luff to leach to accentuate the shape and make measurements easier directly or from photographs. Works great for sail trim during racing, too, of course. For "quick and dirty" measurements, you can use electrical tape but that will not stay on very well.

I hope these tips are useful. Have fun. At the very least, you are bound to learn more about sail shape and improve your sail trimming. I think you are going to be surprised to see what a huge difference even a 1/16 of an inch can make here and there!

Mike

wait a sec... you mean sails aren't just plain triangles? I was confused when the area measurement on my spin didn't equal the calculated based on the foot/luff/leach

mike,

Thanks for taking the time to reply, I got a lot of really good tips out of it. I am definitely looking to do it as a hobby only. Rolf you should make your test spin out of paper, if you were not going to do that originally.

Thanks mike,

matt

I am a little confused about the webbing on the corners that rolf and mike are describing and how they a sew on. I have seen were 3 or 5 webs go to a ring, but I am confused at how multiple webs would meet up with the line do you just tie the multiple webs to the sheet?

Sailcut CAD can not export directly to jpg or pdf, but converting a DXF file to jpeg or pdf should be trivial. The developers are accomodating to new ideas, so if you asked they would probably implement it.


Building a 'test' sail in paper is probably a good idea before you get experience with how your designed shapes will set on the boat. If you hand cut, it's a lot of work tough..
For a spi, paper is to stiff, so I will prefer to do a 1:10 model for experimental work.


The method Mike describes are somewhat documented in "The sailmakers apprentice" that you mentioned. But the reference work is Jeremy Howard-Williams work "Sails". Sailrite also have some good booklets on this method, I have heard.
The main problem with the old method, is how to get the twist you want into the sail. The design software takes care of all broadseaming calculations, so you get the twist and shape you designed into the sail.

You dont need multiple bands of webbing, just align the webbing with the major load path. If you want multiple bands (like for the mainsheet/outhaul on a mainsail), just cut off the corner and use a shacle that you leave on the sail. Use a S-hook on your boom to just hook up the boom to the sail when rigging/de-rigging (saves time). Or get a shacle and grind off the tip so you dont need to turn it to make it enter fully. Use a bungee to secure it when sailing.
Or you could go all the way, and make the webbing long enough to pass around your boom..
This is part of the fun, use your creativity and do it like you want to.