downhill in lighter air

assembly of a wing

assembling the wing

Blunted,

please say that you and your boat is OK!

Ref: http://www.sailinganarchy.com/fringe/2006/images/C-Class%20awsome%202.JPG

The boat is OK but the wing has had better days. I would expect we could be back on the water in about a week.

It was quite the ride launcing the entire boat into the air out of perfectly flat water.\

The foils really do generate a lot of lift at 20knots. Have to be careful about the angle of heel as well or it's all vertical lift and not horizontal lift to windward.

I am familiar with hydrofoilers and what I call "leaping and crashing". The flying hydrofoiler gets a puff, wants to come out of the water at quite a high angle of attack, leaps up then slows while losing lift, and crashes- straight ahead. My catamaran hydrofoilers don't generally want to pitchpole! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> So far, never! They don't capsize either, as the lifting element wants to keep the boat right side up. And they don't break readily. but, you DO have to pay close attention to the mainsheet.

see my webpix: fastsail.com/catcobbler

Blunted,

could you say some words about how the twist mechanism in Cogitos wing is set up (if it is not secret..)? It would be fun to know how they do that. If I ever get around to playing with a mini wing or RC model it would be another touch.

Good day gang.

Just a quick update from C-class land.

The Canadian team is pleased to announce we have taken delivery of all of the "Big bits". This includes, the hulls, beams, foils and most importantly, the wing.

The entire boat has been moved to our island base for final assembly and testing.

Work is proceeding on the final rigging of the wing as we speak and the hulls are all but put together and ready to go at this point. We would hope to be on the water within two weeks.

Two boat testing will commence immediately upon launch of CAD 05.

To date we're quite happy with the build qualtiy of the entire project and it has passed the bench tests so far but the real test is obviously on the water.

We will keep you posted on further developments

from Toronto

Blunted

Rolf, re: twisting wing.

The front prt of the wing twists (elements 1 and 2) and the back part,#3, twist independandtly.

#3 is a bit floppy and has essentially stays running up inside the rig and out to some horns up by the hounds. If you ease the control line the "leech" twists off.

As for the font half, it's more complex. there is a carbon tube up the inside of the LE and it is fixed to a major rib at the hounds. above the hounds the ribs are all gfixed to the tube and turn with the tube if it turns.

Below the hounds the ribs and boom box are free to rotate about the spar. There is a control arm at the bottom which limits the twist and allows for control of twist. think of curtain rungs all free to turn on a curtain rod.

Between these two functions you cover almost all wind gradient conditions encountered, allowing for a flexible, always powered up and not stalling rig.

B

Do you actually "climb" upwind with assymetric boards?

I was told that there would be lots of parasite drag when foils are "climbing" the boat upwind.

I was also told that with asymetric boards upwind the boat actually heads lower while sailing the same course over the water of a symetric board boat. The advantage of heading lower is that the hull would not be generating lift, only the boards - their lift is generated with aproximately zero angle of attack, so the hull is aligned with the flow.

Since the boards are more efficient (long span, etc.) generating lift than the hull, the drag increases slowlyer with speed and the boat sails faster with the same power.

Maybe you are climbing due to other features, like the wingsail? Please let us know - and thanks very much for the great photos and info.

We were out training the other day and making close observations of the climbing in different conditions.

Our goal is to point the hulls straight through the water at zero degrees angle of attack and let the foils keep us in that direction, no higher, no lower, at least upwind. The foil shape, a NACA 64 series foil has a definite drag bucket, meaning an narrow range of angle of attack where the foil generates great lift at very low drag. Even at zero degrees for the foils they generate ample lift to make the boat go straight without leeway. You never realize how fast most boats go sideways until you sail a boat with assy foils.

The boat is pointed a bit lower and just seems to climb to weather, in fact the other guy is just falling away.

Downhill its easy to go to weather with the foils so we pull them up until we're going mostly straight with them or slightly to leeward.

As for the wing, it's just got low drag for the amount of power it generates so that also simply allows you to point higher.

"Little Americas Cup".. lose the name.. Call it the "Fast Americas Cup"

What about 'Intl. C Class World Titles'.

Are the C-class cats an ISAF class? (I don't think they are) If not, use of the word "world" is prohibited too. <img src="http://www.catsailor.com/forums/images/graemlins/crazy.gif" alt="" />

Call it "Too Quick to be the America's Cup" <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Prohibited by who??

C-Class is no longer an international class. Therefore, they are no longer allowed to hold world or international championships or use the words "world" or "international" in any of their events.

Who says so?? The International Sailing Federation (ISAF) says so. Does anybody dare to question ISAF's authority to govern and control sailing in all its forms throughout the world? <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

The threat is that sailors participating in a non-ISAF sanctioned "worlds" will be banned from ISAF sanctioned events for some time period in the future. Funny, yes. I don't know if it's actually ever been tested but it did come up when the Hobie Wave guys put together a "worlds"...they changed the name to something like Inter-Galactic championship or something. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Actually, the regatta was held by the Turks & Caicos, and it was the Wave World Championship. As far as us promoting it in the United States to get people to go to it, we were under intense pressure from ISAF and from US Sailing to change the name to something that would not imply in any way that it was a world championship. They suggested "Intergalactic," because, thankfully, ISAF has not yet extended its governing authorities beyond this planet.

The only reason we knuckled under and briefly changed the name to Intergalactic was because we had a youth sailor coming to the event, and we did not want him to be disqualified from being able to race in ISAF youth events just because of participating in the (illegal) Wave Worlds.

As it turned out, he came to the event and won the whole thing. And his trophy says "Wave Worlds."

that story warms the **** of my heart.