Fixed wing sail controls and drawings

Is there a good resource to see how people have built controls, wings and material?
What is the best material, method to skin the foil?
I am also interested in a ridgid 2 section foil with a third leading edge with normal sail cloth and battens so I can depower or dump the sail.

building a 24’ long power trimaran with max 8’ beam. Wanting to use sail to motor sail or turn off motor and enjoy the sail. I have a carbon fiber wind surfing mast for the mast. Maximum sail height 8’ tall and maybe 4’ wide??

 

I am also interested when you figure it out.

You need dagger boards as well, and ideally the dagger board similarly has a trim tab, or at least can rotate a few degrees to maximize lift.

 

Peter Worsley's site, Wingsailing and Rotary Sailing http://www.sailwings.net/ has a page on construction methods, and links to other sites. He does have a youtube channel (https://www.youtube.com/@WindThrusters/videos), but does not discuss construction there.

 

Never thought about trim tab! I will keep you posted.

 

Awesome mate

 

A sail of that size on a power cat will barely move it. Reality proves that the optimistic claims for the (alleged) advantage of fixed wings over soft sails are enormously overstated. In most classes in which they have been tried, even by experts, fixed wings were significantly slower than normal sails. Years ago this forum used to have two aerodynamic pros who had designed America's Cup winning fixed wings and they described why wings don't really work in most craft.

The mere fact that a wing has thickness does not make it significantly better as a sail, but it does come with major problems.

The guys who sail America's Cup wing sailed boats and do NOT use wings on their small craft are not ******. They stick with soft sails on their Moth and A Class foilers because soft sails work better.

 

If it's ideal why don't the world's top sailing craft use them?

Windsurfers can easily rotate their foils (and hulls) to windward to maximise lift - but they don't because it's far slower. A windsurfer can easily point its foil straight to windward - but then it stops.

The late Tom Speer (America's Cup and Boeing wing designer) used to explain why rotating a foil doesn't really work on this forum. In essence, "rotating the foil" changes the relationship between the foil and the hull, but it does nothing to change the relationship between the foil and the apparent wind angle, which is the important bit.

 

This forum used to be frequented by Steve Clark when he owned and had built the world's fastest small craft,the wingsail C Class cat Cogito. Maybe searching his posts could help.

If you've ever looked at a wingsail you'll see some extremely expensive and complicated bell cranks, control arms etc. There's a reason such a large proportion of them seem to be owned by extremely rich people. I used to have a mate, a professional cat designer, who was funded (IIRC) by a Qantas pilot to build one. It didn't work.

Having had carbon windsurfer masts since about 1984 I'm baffled to see how they would work with a wingsail. Windsurfer masts bend, wingsails don't.

Windsurfer rigs can have many of the aerodynamic advantages of wingsails, but an 8' x 4' one would be slower, in my experience, than the rig in any well known craft on the water. The rig of an Optimist dinghy, the slowest popular boat, would probably be dramatically more effective.

Look at the vids on Peter Worsley's site. The boat is moving very, very slowly compared to what similar hulls can achieve with normal sails. The people who use normal sails aren't fools, they use them because they work better.

 

Ok so much to think about. The intended 24’ power tri is only 8’ between amas so, didn’t think the sail would be too big and since it is 8’ wide, didn’t want to capsize.

 

Cheers. At 8ft and with a considerable displacement, you'd have far more stability than something like a Hobie 14 or Maricat 4.3, which have much bigger rigs. I'll try to think of a comparable boat to yours, and what rig works on it.

 

Having had some experience with motorsailing since we went electric (range vs speed issues), a few observations-

Going upwind motorsailing has problems with apparent wind, so you have a few ways you can go:

- go for a really insanely good upwind rig, which in light airs motoring will be at best footing- this will not work well for tacking up wind- getting more than 90-100 degrees will be difficult, and a good light air rig upwind without a motor is going to be big, and more expensive.

- motorsailing off the wind works well, but if you want to reach in light air, motor driven apparent wind is again a problem, so you’re back to a bigger more expensive upwind rig.

- BUT! If you want to sail off the wind with no motor with something easy, an offwind sail will do nicely, whether a symmetric spinnaker, assymetric spinnaker, square sail, some sort of lug, sprit, gaff etc. the advantages of the last 4 being

-shorter lighter spars,

-handling,

- staying

- or go freestanding.

- sails less complex, you could even go with a stronger nylon cloth

- rigs under less stress, which gets a smaller spiral going.

you could use a windsurf mast(s) for top spars, & and a short stiff bottom mast won’t be hard to find or make whether aluminum, wood, or carbon

The others will work well, check out what kayak/canoe sailors are using- small light assymetricals. all over the place.

If you don’t sail upwind, all sorts of possibilities open! WhenI was a kid, we had a good friend who would motor upwind 10-20 miles in his ChrisCraft sedan, turn around, deploy his square sail, kick back, and enjoy the sail back to the marina. He even could broad reach in light weather.

 

Thank you

 

Hi there,

I have an ongoing project with twin wing sails. I am currently documenting the whole process with insights into foil selection, construction and build techniques on my insta: https://www.instagram.com/carbon_pirate/
I am documenting the whole project from the past to today and beyond. So might take while until I catch up there to the current status, but if you need any info, just contact me.

best,

Marcus

 

mate, I just followed you! You are doing some awesome work and will follow what you're doing. I plan on vaccuum layup and infusing.
what NACA foil did you use?
dimension of sail? Sail area? total weight?

 

Hi Forecaddie,
I am using an Eppler 392 for the hydrofoils. It is similar to the often used NACA 63-412. You want the lowest possible drag (with the infamous drag bucket in the Cl vs Cd graph: NACA 63-412 AIRFOIL (n63412-il) Xfoil prediction polar at RE=1,000,000 Ncrit=9 http://airfoiltools.com/polar/details?polar=xf-n63412-il-1000000). Also the low pressure zone should have no sharp peaks to avoid flow separation.

I did use vacuum infusion and vacuum layup for my foils. Vacuum infusion worked great for the hulls. For the foils not so. The high vacuum needed for the infusion compresses the unidirectional fibres that you use in foils so tightly, that the resin can not be sucked through and you end up with a partly soaked laminate. At least that is, what happened to me. For the foils I am back to hand layup with vacuum bagging.

One Wing weighs a little under 30kgs. I am a bit on the heavy side because I wanted to use the wings on a regular basis and so I needed more stability than for a race setup. Also I am using the wings essentially unstayed. So my central tube is more massive than what it would need to be when using stays.
I am using a NACA0016 for the forward element and a NACA0010 for the aft element.
Wing area is 11,7sqm per wing. Wing height is 7,5m for the wing itself and another 0,6 for the central tube that sticks out and acts as rotation axis for the wing. So in total 8,1m