Laser Foiler!

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You MUST have some form of altitude control-using a fixed foil without it won't work unless the main foil is adjustable on the water. Just adjusting the rudder foil might work to some degree but rudder only is not likely to be a stable form of altitude control for a sailing hydrofoil.
The foiling windsurfer and kiteboards use two foils mounted to a single strut with crew weight movement for altitude control but that would be really hard to successfully do on a Laser.
A real good solution that hasn't been tried yet is Mal's innovative surface piercing foils mounted on a single strut-see renderings below. This would require a lot of experimentation to get right and allow retractable foils. A surface piercing foil regulates altitude with speed so you have zero moving parts. This has tremendous potential.....
A warning: reinventing the wheel is fraught with frustration so unless you have someone to work with that really knows hydrofoil design you'd probably be better off to buy the Glide Free system.

 

Thank you for the explanation!

Based on your comments, what I'm now thinking of for experimentation would be to start with perhaps a smaller, lighter AMF Minifish hull, weighing 75 lbs. That boat would be more sensitive to my 200 lb weight placement, and with a Laser Radial-sized sail still have some power.

Aside from skipper weight placement, it occurs to me that have a strut that is narrower than the daggerboard trunk would allow for a for/aft adjustment that could allow for angle adjustment, though that is getting more complex than I was hoping. The Mal design illustrations you provided are interesting.

Now for the rookie question: how are the current AC boats getting foiling stability? I guess I don't understand how they are adjusting for altitude, as their foils don't appear to be adjusting underway.

Thanks again, by the way.

 

This may help-I wrote it to explain(as best I can) the TNZ foiling system on which all the others are based. It was posted in an rc forum hence the reference to my test model and the picture below as a reference. For this post I'm adding a rough sketch of the TNZ main foil and a couple of windsurfer foils: ( you can go to the 34th AC thread and quite a few pages back there is a video posted showing Oracle moving the main foil manually(electro-hydraulically)-shifting from take off mode to a cruise mode. If you look carefully you can see the head of the foil move forward)

The TNZ system is , first, a three foil system with a single main foil. Most foil incarnations on catamarans had three or four foils in the water and nearly every one ,whether three or four foils, had two main foils. Second, it uses a combination surface piercing curved daggerboard and fully submerged "L" foil to form a "V" foil where the inboard foil tip of the "V" sometimes breaks the surface as back up altitude control. Primary altitude control is a combination of the angled and curved surface piercing daggerboard that provides a limited range of altitude control-similar to a "traditional" surface piercing foil except with a limited speed range. The limitations of the speed range are overcome with manual adjustment of the angle of incidence of the foil which varies the lift on the "L" side of the "V" as well as on the curved daggerboard. So, when speed exceeds the limited range or falls below the range the angle of incidence is adjusted. It is a brilliant, low drag system that has a lot of variability possible within the basic design, so that, for instance, the speed range, effective for altitude control, can be varied by changing the angle of the board(to vertical), the radius of the daggerboard and/or the cant of the whole foil.

So it is possible to design a foil using this concept that requires very little or no manual adjustment of the main foil angle of incidence-especially on C Class boats where, for example, the rudder AOI is adjustable under sail(illegal in the 72's).

So, to summarize the three foil TNZ invented configuration featuring a single main foil with a unique design featuring elements of fully submerged, surface piercing ,"V" foils with manual AOI adjustment ,if required, is revolutionizing catamaran hydrofoil systems with speeds(particularly as multiples of windspeeds) unheard of in catamaran foilers. And part of the brilliance of the design is the fact that it can be refined to work in a wide range of applications-like for instance on my MPX Test Model trimaran foiler as an ama foil working in conjunction with the main hull bi-foiler configuration.

Pictures left to right- 1) model ama foil based on TNZ main foil with refinements based on its use; 2)-rough sketch of TNZ main foil ,3) air chair/rush randle type foil system optimized for jumping and re-entering, 4) French windsurfer foil system optimised for efficient lift/speed-not jumping.

 

Because it makes the boat non beachable, while the foil is inserted. Most of the small dinghies I've seen sailing are sailed off the beach and are treated quite casually, like a kid treats a bicycle.

With a plain dagger board, you can do that. With a $5,000 appendage, you cannot.

Dinghies that must be tied to a wharf or a dock are a lot less likely to be used than those that can be sailed off a beach (and onto one).

That is my point.

Besides, this thing goes 20mph. How fast does an ordinary Laser(tm) go?

I'll guess at 13mph.

Now. to go 50% faster, you need to invest another $5,000, and you need a dock or wharf to tie up to.

Like I said in my post, there should be a good number of takers.

But there will be even a larger number of leavers.

 

They claim it can be launched in knee-deep water, which makes sense since the daggerboard/foils can be raised, just not completely. Check out the pictures on the link:

http://www.lasersailing.com.au/index.cfm?eid=1123&ntid=1361

As to the $5k 'investment', that's what these boards are here or. This is an exciting concept for us traditional dinghy sailors, but is it the best, most efficient,and most cost effective approach?

Once we get the optimal design down, this this can't cost more than what, a few hundred dollars to actually construct? Under $100? First adapters might pay up for this first pass at a solution, as they always do, but this particular board system may be the first word, not he last.

 

Chenier;

There are some very good amateur builders with vast experience in boats like Moths and A Class cats who have tried, and now abandoned, the idea of making their own foils. To make them tough enough is a major problem.

Sharpii;

While many people do treat dinghies like bikes, many competitive Laser sailors down here treat Lasers and similar boats with a great deal of care. I never let my Laser's bottom touch anything but air and water.

The Glide system looks beautifully thought out. They have even ensured that the raised foil doesn't hit the boom, which would have been a significant issue. The cost is still a major issue as far as widespread popularity, IMHO.

 

Good question. I think the right answer is to look for a used Bladerider (fibreglass model) which can be had for around the cost of just the foil for the Laser. You get a better foiling platform, better chance of actually foiling and you keep your Laser as well. Problem solved.

--
CutOnce

 

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I would be real leery of that. Even a good Moth is fragile and the Bladerider went out of business for poor quality builds. Not only that, to launch you have to wade out to chest deep water before skampering aboard. And the Moth is very, very unstable off the foils-one of the big advantages of the foiling Laser is stability off(and on) the foils.
I don't think you get a better chance of foiling at all, but you get a faster boat once you master the Moth. If you bought a new Laser and the foil package you'd have an excellent product at about half the cost of a new Moth.

 

Another video from PSA: http://www.youtube.com/watch?v=ZdZ7iVkD7rs

 

Needs a wing...

 

Moth vs Laser

Doug,

Despite repeated offers, including the offer from some of the top mothies in your country to pay for plane tickets a number of years ago for you to give it a go, you haven't sailed a moth. What you don't realise (and yet gladly profess) is that they aren't beyond the realms of the average sailor to sail, you just need to alter your techniques. It's a skinny boat, so the cardinal rule becomes "when in doubt, sheet out". At low speeds, the foils add a lot of roll stability (compared to a lowrider moth) due to entrained water, and once you're up and foiling you have more than enough force to balance your weight. The tricky bit is gybing and tacking, but that takes time and practice to master in any boat.

The laser foiler is a good idea, don't get me wrong. I like it. However, I see this as something that a bloke at a club will buy one set, which will get passed around the club fleet as a bit of fun and then they'll either all decide to go do the foiling thing properly (and moths will grow as a result), or they'll decide it's too hard and pass the foils onto the next bloke.

The price is a bit nuts though - my current moth cost me AU$4000 (although it was a steal)... and yes, it's full carbon with decent fastacraft foils. If the price point was $2500, it would be a very different story. Just look at the rooster big rig for lasers - they're getting big numbers, because it's a cheap upgrade that allows the big boys to have some fun. If these foils were the same, they'd sell like hotcakes.

 

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This isn't about the Laser vs the Moth. This very forum has the largest(most views) Moth thread on the internet -started by me. This thread is about the innovative new Laser foils. The price seems high to me too, but the fact is you could buy a new Laser with those foils for about half or slightly more than the cost of a new Moth.

BS-the so-called "offer" was disingenuous horsemanure at a time in my life where I was care giver to two elderly parents. It was made by some of the most despicable people I've ever run into on the internet. Further, I sailed and foiled a bi-foiler of my own design years before most of the so-called "Mothies" in that forum had ever foiled anything.

 

AC foil system

Correction to post 33 where the effect of leeway on altitude control was not fully understood followed by Magnus Clarkes succint explanation of the AC 72 system from Seahorse and posted in the LAC thread:

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Quote from Magnus Clarke on the AC foil system:

"The Emirates Team New Zealand system, which is really the basis for C-Class foiling, relies upon the use of leeway to moderate the effect of the lifting foil and to help make the boat heave stable. As the boat sails down the track and begins to fly it speeds up a great deal due to reduced drag. This extra speed alows for a great deal more lift to be produced by the foils and so the boat rides higher, as the mass is constant. As the boat rides higher there is less foil in the water. If the strut is principally responsible for limiting leeway there is now less of it to do the work of keeping the boat moving forwards. The boat automatically corrects for this by yawing, at which point the strut will use a higher angle of attack caused by the leeway to create a force equivalent to the wing's side force.
The leeway, however, has an effect on the effective angle of attack that the foil wing experiences. As the boat crabs sideways the wing- or relatively horizontal- portion of the foil sees a lower effective angle of attack and as such the lift produced is moderated or reduced until the boat itself reaches dynamic equilibrium. This is also aided by the inboard tip starting to breach out of the water-this reduces available area to create lift for the boat and also leads toward dynamic stability in heave."

 

Laser Foiler

New website for anyone interested in the Laser Foiler: http://www.glidefree.com.au/

 

It would be nice Doug, if you personally owned your failure to understand how this worked rather than putting it in the 3rd person.

some of us understood it when you did not - so its rather noxious for you to implicate us in this error even if by your using the passive 3rd person voice