Battens - The following tubing is used to build telescoping antennas so it is designed such that the incrementally larger or smaller tubes slide into each other with a tight fit:

Aluminum 6061-T8 tubing.  3.65 meters x 50mm od x 3mm wall (also available with a lighter 1.5mm wall in 6063-T8).  Weight for the 3mm wall is 1.24 kg/meter and the modulus is 69 GPa.  The necessary single splice to get to the 4.1 and 4.75 meter battens , given my skillset, would be to sleeve, glue (urethane), and rivet rather than weld section together.  

They also offer pultruded fiberglass tubing.  To get similar stiffness to the AL tubing I would need  76 mm od x 3mm wall tubes since at 17 GPa, the AL is about 4x stiffer.  Weight is advertised at 1.31 kg/meter, so it is also 6% heavier. I am thinking that the failure mode is a little more dramatic than the AL, too...   

would the AL tubing discussed above be OK for the boom/battens of both sails?  Are there any good reason to go with the fiberglass over the aluminum?

Erik

scratch all the above - turns out getting six meter AL tubing in 2" (50mm) od and varying wall thicknesses from 1.5, 3, and 6mm is pretty straighforward and reasonable in price.  Also the od can be gotten in 1/4" increments, so going to a 2.25" or 2.5" tube is simple.

e

I think this is looking very good, too, and I can't see any way to improve on it. I like the aesthetic appearance, as well as the function. Just one thing: with the single 3:1 sheet and multiple spans, you have got a little less than the PJR-recommended Dmin = 2P. The sheet may not come quite taut when the sail is stowed, but will be OK when sailing. The answer will be to tie a line around the sail bundle and take it out to one side of the boat, to stop the bundle swinging to and fro at anchor. I'd do this anyway, even if the sheet is taut, to save on wear and tear. If you used upper and lower sheets, the spans would be single, so no problem; but as we've said, the rigging can be changed fairly easily, once you are sailing and can see what is actually needed, rather than what appears right in theory.

Circles and ellipses Oh my...  

So I've spent some time hopefully refining the sailplan.  CAD and pdf files are in the Box, a jpg is linked below.  Can somebody confirm that to determine the sheeting angle, a perpendicular line from the deck block to an ellipse defined by the sheetlet is the correct method?

The pdf/jpg is a bit messy because of all the info on it.  Most of the new drawings are related to making sure the sheeting will work within the constraints of the Freedom, including D_min, and max/min sheeting angles.  Circles, lines, and ellipses drawn appropriately and hopefully not too confusing. 

Arne - I borrowed your idea of a shorter boom to both help with the batten stagger and to give the sheets enough room to "fit" between the clew and the deck  

David/Arne/anybody else for that matter - if you could give the the drawings some level of "blessing"/review that would be great.  I would like to make any final necessary changes this week and start discussing and working on the panel/cloth layout for a hinged/cambered sail.

Thank's everyone for their help so far!

 Erik

Erik,

could I suggest you read through Paul Fay's articles about rigging his schooner Ti Gitu? Those sails have very high AR. Paul had a bit of a struggle, to begin with, before he cracked the code:

http://www.junkrigassociation.org/technical_articles

Just a thought

Arne

David - (your latest reply caught me mid draft on my response.  Ships crossing in the night and all that...)    

Schooner Rig:  I will stop taking sailing jargon freedom with the Freedom sail plan - until further notice the mizzen is now the mainsail and the main is the foresail and we are officially a Schooner.  Hi :)

Sheet purchase:  We have a pair of Andersen 46 two-speed self-tailing winches, one for each sail.  I definitely understand that a 3x1 sheet by itself would not work well.  Our current sails trim in fine with that amount of purchase and the winches.  

Halyard Purchase: Along the same vein...  I was hoping to get away with a single or double purchase halyard.  As is, I can winch the girlfriend to the top of the mast and she may be similar in weight to the junk sail (now that will put pressure on me to keep light sails). But as you say, running rigging changes are relatively easy. 

Top Sheet Batten:  Check!

AR - The Version 2 design, which resulted in your push for a higher AR on the main had, I think, about the same AR as you have on Weaverbird.  You've previously stated that you would have gone for a larger AR sail if your mast was taller.   What are the pros and cons and possibly limits of this.  I see that one of Darren's current sail has an AR above 2.9 but for a different planform.  If there is one worry it is that I push the design too far outside some proven standard and end up with unanticipated and worse, non-correctable problems.  The sheets - I would love to do a single sheet and will try it, but can live with a double if necessary.  So no worries there.  Unmanageable reefing is less acceptable.  I have re-read the very helpful limits you advised here regarding P/B and camber.  The design still seems to still fit within those limits for a 8% camber that is made up of 4% sail cloth cut and 4% hinges. 

P of 1.6m:  See above.  It is my preference to have fewer panels to save weight and allow for simpler sheeting.

Top Sheet Batten sheet standoff:  I am thinking of using a "flicker" as is often used for a fat headed BM.  Some incarnation such as this: 

Sheets, D_min, and other scary things:  Six point, three part sheeting system.  Bottom equal power three point span (Page 68, Figure 4.28 in PJR with a Dmin of 1.75). Upper three points with an anti twist (Page 64, Figure 4.14 or 4.16) for a 1/3+, 1/3, 1/3-, 1/2++, 1/2, 1 pattern. 

Annie - I have been struggling with where to stow the sheets and halyards and you have inspired me to re-think the problem.  Bags don't work, and a tall box would not either.  But it may be that a shallow, almost false bottom, in the front portion of the cockpit floor may work.  We will see.  

Darren - Please come visit!!!

Erik