MacGregorSailors.com

IIRC the primary principle of a loose footed sail is the extension of the sail shape from the head to foot of the sail. Whereas as a footed sail bound to the boom via the bolt rope flattens the sail shape thus reducing performance. As stated previously the flattening of the lower part of the main by a footed sail may be to your advantage in high winds the opposite is true with low winds. Changing the outhaul on a footed sail has essentially no effect on the foil shape whereas with a loose footed sail you can control foil shape in the lower part of the sail. With a loose footed sail and outhaul you can choose to flatten or deepen the draft as needed. When it's all said and done maybe you gain .1knt.... One thing for sure replacing the my OEM sail with new higher quality sails (BWY) was a significant improvement in performance. Well worth the $ spent.

1st Sail wrote: ↑Wed Apr 08, 2020 7:28 pm IIRC the primary principle of a loose footed sail is the extension of the sail shape from the head to foot of the sail. Whereas as a footed sail bound to the boom via the bolt rope flattens the sail shape thus reducing performance. As stated previously the flattening of the lower part of the main by a footed sail may be to your advantage in high winds the opposite is true with low winds. Changing the outhaul on a footed sail has essentially no effect on the foil shape whereas with a loose footed sail you can control foil shape in the lower part of the sail. With a loose footed sail and outhaul you can choose to flatten or deepen the draft as needed. When it's all said and done maybe you gain .1knt.... One thing for sure replacing the my OEM sail with new higher quality sails (BWY) was a significant improvement in performance. Well worth the $ spent.

Excellent info 1st Sail! So if I can add 0.1knt, that would double my typical sailing speed!

If I hear you and Tomfoolery correctly, the adjustable outhaul may not need to move to the top of my project list. Thanks guys!

What's the proper etiquette on this forum about reviving an old thread? Should I have asked the following on a new thread?

(1) I definitely want to try a loose footed mainsail. Can the stock M mainsail be used this way? Mine has reef points in case there are multiple versions. My gut feeling is it needs some reinforcement at the tack and clew (like finger spread from those points).

(2) Has anyone ever done a realistic before and after? I know from foil theory, keeping the shape to the bottom is better in a 2D sense. BUT, I also know that the high camber at the bottom causes a far larger vortex that actually reduces most all of that advantage.

(3) This is the one, I'm really interested. I know you relax the outhaul to give more camber.
(a) What is the maximum measurement of the foot away from the boom you typically experience?
(b) I'm assuming this is in very light wind??? That you tighten it up for higher winds???
(c) Do you think that maximum deflection point is at the mid point of the sail or at the airfoil optimum 1/4 to 1/3 point?

Thanks and VBR.

Looking at this post, it almost looks like the apex is nearer midpoint. I'm not sure it would naturally go to the 1/3 or 1/4 point when only fixed at both ends. Maybe add some shaped battens?
viewtopic.php?f=7&t=27620#p341371

Sorry I can't answer etiquette questions.

Jimmyt wrote: ↑Tue Apr 07, 2020 8:34 am Fair discussion in this article. http://www.fxsails.com/article_loosefoot.php

I don't have any trouble reefing mine. I just roll it up. Supposed to be as easy to Reef conventionally though.



But, I do need to add outhaul control and get my halyard squared away to get my sail shape looking better than my pajama shirt...

Excuse my ignorance but that looks like an above the boom furling system. Is is manufactured or built by you and what more can you tell us about it? Quite interested!

Down South

DownSouth wrote: ↑Sat Oct 24, 2020 3:01 am Excuse my ignorance but that looks like an above the boom furling system. Is is manufactured or built by you and what more can you tell us about it? Quite interested!

Down South

I had the same question and know no more than what I found in the forum. In a nutshell, it was something that was "not quite" a factory option. It doesn't sound like many were built/sold. There are several (currently) active members with first hand knowledge. Jimmyt and Boat seem to be on opposite sides of coin about the desirability of it. Here were the main threads I found:

viewtopic.php?f=7&t=27620&hilit=loose+footed
viewtopic.php?f=9&t=25987&hilit=loose+footed&start=15

It was an option, I believe from a particular dealer. It is crude, but serves its purpose to a degree. Lazy jacks and slides would be as easy, if not easier to hoist and drop, but wouldn't give you the infinite reefing that roller furling does. However, roller furling doesn't always produce the best sail shape. It's handy for trailer sailing. When you mount the boom on the mast, the main sail is already loaded and ready.

Inquisitor gave some links. Also, see

viewtopic.php?f=7&t=16601&hilit=Roller+ ... in#p339876 .

If anyone has questions, I'm glad to try and answer them.

I think BOAT and I pretty much agree. We just enjoy a good argument.

Inquisitor wrote: ↑Fri Oct 23, 2020 2:05 pm (3) This is the one, I'm really interested. I know you relax the outhaul to give more camber.
(a) What is the maximum measurement of the foot away from the boom you typically experience?
(b) I'm assuming this is in very light wind??? That you tighten it up for higher winds???
(c) Do you think that maximum deflection point is at the mid point of the sail or at the airfoil optimum 1/4 to 1/3 point?

We flatten ours--which is loose-footed--in high winds, but also in very light winds. I think it is harder to keep laminar flow in the light winds. Our draft ranges from mid-point to probably 40%. Late in the summer we put a little more bend in the mast, which helped move the draft forward.

--john

Is it possible to loose foot the stock mainsail? I'd hate to rip off the clew. A new mainsail is not in the budget (yet).

yes, I think this is easily doable.

Just put in a slider at the end in the boom, the attach the old sail at the slider. Then pull the sail as ever.

On my mainsail I had the bolt rope removed & added a slider , added a 3rd reef & had the clew & tack corners re-inforced to make it loose footed
then designed & fabricated an Inboom outhaul







J

Highlander wrote: ↑Tue Oct 27, 2020 5:26 pm On my mainsail I had the bolt rope removed & added a slider , added a 3rd reef & had the clew & tack corners re-inforced to make it loose footed
then designed & fabricated an Inboom outhaul







J

Jeeze! I'm glad you mentioned this. I think I've adjusted the stock outhaul... maybe... two times. AND OF COURSE... there's going to be a pretty sizable load on it. Making it inside the boom and turn around close to the mast... PRICELESS! I can let it out when already off wind and its hanging over the side.

I see you have a 3:1 on it. What are your thoughts after using... enough, too much, not enough?