Peoples Foiler-flying for the fun of it!

People's Foilers Another ?

I have watched vids of the Moths flying and some I14 runs and found them fascinating, though the Moths are really not for an old traditionalist like me.

Anyway, I still do not understand how a glass/carbon foil can handle the loads like a I14 might dish out, thinking metal like aluminum might be stronger, but like I indicated, I know zip.

I also do not wish to hijack the thread, so if you can point me to some links, I can research.


You gents got me thinking...always dangerous. I see a turbo-ed, no stayed flex masted dinghy with a RS Vario or windersurfer main...foiled.



Thanks.

 

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The Rave multifoiler uses extruded aluminum foils but the new boat by the same designer uses molded carbon(no glass) for stiffness at lighter weight.
You might read the "Foiler Design " thread in this forum and some others have good tidbits....

 

Thanks Doug, I saw it earlier and was going to study it tomorrow, but now works too.

Some time later...got to page 3 so far. Learning!

 

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This paper may help-it is a systematic study of what makes a Moth fast or slow-can help for all foilers:

 

The design (so far) has a sleeve inside the CB case which is inserted from underneath and locked in place. A small faired flange spreads the load from the sleave to the hull around the bottom of the case. The main foil is then inserted into the sleave from underneath. For launching, the foil will be raised as far as possible, but will still project 100mm or so below the keel line. Once deployed, the foil will be simply held down by a rope that runs through a hole or slot in the top of the foil vertical strut. The rope only has to support the weight of the boat and helmsman, plus a bit of dynamic loading. The rope will be attached at both sides to the top of the sleave which protrudes throught the top of the CB case (fixed one side, cleated the other), so the loads are all trasmitted to the bottom flange. The rope needs a name.

Progress on this project to date has been slow. At the current rate it should be up and foiling some time in 2064. I did buy some epoxy the other day, specifically for this project, so that's a start. On the design side, I have introduced some twist into the main lifting foil. This is apparently necessary due to the sweep angle, but may also be useful in that it may help to reduce the chance of ventilation when the foil pierces the surface (if it ever does). I've calculated that it needs about about 6 degrees of twist from root to tip using the Culver twist distribution formula.

 

mal, why dont you fitt two eyes at the top of the center board case either bside of the foil, drill a hole through the top of the foil and put a locking pin through , more secure than a rope. The 600ff works on a main foil angle of 8.5-12 degrees. but i suppose it depends on the foil desighn.
Matt

 

I've though of a few alternatives, pins included. A pin is more expensive, something else to loose, and would be more fiddly to fit in place on the water. The rope is permanently attached and can be used to pull the foil down into position. I'm also trying to stick with the original Laser KISS philosophy.

Although in the end, a pin system might be necessary.

 

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Matt, could you doublecheck those figures. Is that 1) angle of incidence(angle relative to something on the boat, or
2) angle of attack-the angle of the foil relative to the flow, or
3) are you refering to the angle of the daggerboard from vertical?
In either 1 or 2 that is way too much angle-almost any foil would stall at that angle. It would help you(and me) to be very precise when referring to angles..
It is critical to always understand what the angle is in reference to-thats why
terminology like "angle of incidence", "angle of attack", "vertical rake" and others were invented.
Please try to get the foil planform areas(just the area of one side of the foil) when you get the time-and good luck.

 

Here you are Doug, lots of peoples foilers

http://kitefoil.forumactif.net/discussions-foil-f3/

 

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Thanks, Cheesy-thats cool suff!

 

A Working People's Hydrofoil

Wow. I'm so glad I found this thread. I have been working on the concept of a "people's foiler" for almost two years, and I'm excited to share my work and ideas with people on this site, and even more important to learn new ideas. Although I agree with most of Doug's design goals, my own were slightly different and therefore the boat that I came up with may not meet all of Doug's goals. Still, I feel people here may be interested. Here were my goals:

1. Be able to carry at least two 200lb + people.
2. It needs to be able to be quickly disassembled for easy transport.
3. The individual pieces of the boat need to be as small as possible for easy storage on the deck of a cruising yacht. (no long skinny catamaran type hulls).
2. The occupants will sit side-by-side to invite a more social and relaxing experience for first timers and students (and attractive co-pilots!).
3. The foils will provide all righting ability when foilborne. (no water ballast, athletic weight shifting, etc.)
4. The boat must be able to run in the 6' to 8' foot chop that are ever present here in the Caribbean.
5. Low takeoff speeds (< 5kts).
6. Top end speed is not a priority.
7. The boat will be manually controlled in pitch, roll, and steering when in flight (no autopilots, sensor wands, etc.)
8. The boat will be quick and easy to learn.
9. It must be very difficult to capsize, or "crash" from having a foil break the surface.
10. The boat will be beach able with easily retracted foils.
11. Here is the biggest catch, and it won't be a problem on the production version, but the boat must be dirt cheap to build. For me, that resulted in plywood and fiberglass construction, even for the foils! My mast is a piece of bamboo cut down locally. (Many race boats on my island use bamboo masts).

As I side note, I had to build this hydrofoil on the deck of my 43' sailboat while at anchor. This influenced some of the design ideas for the prototype, and will be addressed in a production model.

I'm posting this in an attempt to elicit people's responses as to the suitability of this design as a "people's hydrofoil". I'm very open to criticism, so bring it on!

Please check my blog to see pictures of the "Valkyrie": http://corycraft.blogspot.com

 

Best of luck with your research. I'm not so sure that your design will work without a pretty big rig, which will impart its own problems. Your desire to explore different possibilities is to be commended.

Perhaps the biggest area of respect that you have gained from my observation, is that you have built something, you are out testing it and most important, you are sharing your build/test process openly with a written blog and lots of illustrative photos. You are so much further down the line of discovery than some folks and I congratulate your efforts.

 

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Cory, your concept is interesting I wish you lots of luck. Don't miss the specs for some already existing foilers that you can find in "Foiler Design". Do you have any numbers for your proposed design-like SA/ws, sail area etc? How do you intend to provide righting moment?

 

Cards, I agree it will require a fairly large rig. Originally, I had intended something similar in size to an I14. I can't give exact SA numbers until I experiment for another week or so. WS at rest will be approx 40 square ft. Foilborne, about 20. The weight, including all gear, should be around 250lbs. These numbers are very general, as I am very much an amateur. Righting moment is provided by two amas (not seen in most photos of the testing) when at rest or sailing on the surface. Foilborne it will use ailerons. The boat isn't intended to be foilborne all the time. I estimate 12 - 14 knots of wind will be necessary to get foilborne, but where I am in the Caribbean the trades blow like that almost every day!

 

Peoples Foiler 2010: what it isn't

This description of the launching of a Moth from Phil S on DA shows very well what a Peoples Foiler is NOT:


Posted Today, 05:23 PM

The space problem for moths is that we all capsize the boat on shore to fit the foils. We then carry the whole boat on its side into the water, balanced on one shoulder, not a heavy load but a cumbersome one. This is much better than putting boats in the water upright, walking out to foil depth, capsizing to fit foils, losing pins and heavy foils sinking, and all together blocking access to the lake for everyone else who is trying to launch.

ACat upright needs 5.5m x 2.3m plus walking space. Moth capsized needs 7.3m x 4m with foils atached.
Phil S
Moth AUS 3574, My moth Blog
2011 ZHIK Moth Worlds Belmont NSW
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One of the most important elements to any Peoples Foiler wanabe will be ease of launching without having to wade out to the deep water or insert the foils every time you go sailing. The boat will be transported with the foils retracted and be launched like any other dinghy and sailed off the beach-not walked off the beach.
The requirement to get soaked every time the boat is launched will be gone for good. Key features of the Peoples foiler that will allow this are excellent "seahugger" stability(off the foils) because of well designed and effective buoyancy pods and retractable foils.