why trade forward drive for lift when fitting T foils is (IMO) a better solution?

That's a great point--my new spinnaker (Glaser) has my bows riding a noticable 2-3 inches higher; that a nice added cushion going downwind.

No, mostly because I'm also aiming at improving my boat on two points where I don't fly a spinnaker.

Beam reaching my F16 is kinda sensitive in the fore-aft direction, I have to back off in a blow or make sure I'm really on top of thing. I do sail/race in light but gusty winds now and then and my boat significantly drops it bows everytime a gust comes along while I sit near the mainbeam for proper balance. A Blade does this significantly less. No spinnaker is hoisted on these course and so it can't be a factor

The third area of improvement is spinnaker sailing in steep chop. In flat water i don't have much issues at all keeping the spinnaker drawing and the boat at speed. In severe chop it is become really sensitiv, partly because of the relatively small rudders by AHPC and the fact that they can stall on the worst moment of all.

But I do think it is a little bit of everything. Both a newer spin and T-foils will help and combined the result will be better then just having only one.

Wouter

Robi,

At Zandvoort the conditions were well suited for testing out t-foil effectiveness. AS Mark P had injured his knee, this only left John Alani to show off how the t-foils could help. I personally noted how much smoother the older Stealth was thru the water upwind compared to the majority - mind you John Alani's boat was one of the heaviest boats too.

I personally did not feel the need for the t-foil off the wind. IF the boat doesn't nose dive - why do you need the t-foil.?

Sure the t-foil has that look that attracts many people, but the items also need to be effective. The F14's that sail here in Adelaide need the t-foil as they have a higher power to weight/waterline ratio's that the F16 and their hull design is very different to the Aussie Blade.

As i said in a previous post, upwind is where they might help the Aussie Blade F16. And given the t-foils are fragile, difficult to make any adjustments, awkward with beach rollers, create difficulty in the surf - I for one will approach them with caution & a last resort.

Wouter - I understand the dollar implications, but the reality is you are generating a lot of hype over t-foils for boats that were not designed for the F16 rule in the first place. Your boat is 20kgs over weight & wrong hydrodynamics for spinnaker sailing.

Marcus

Marcus:
Thanks for the simple reply. You got a PM.

Well it isn't 20 kg overweight really, just 15 kg (= rounded off upwards). Yours was 5 kg overweight before adding a jib setup so the difference between our boats is somewhat smaller then we may think.

And as far as I can tell my boat is a pure F16 in every respect, got the measurement form to proof it.

I also noticed some Blade owners putting their bows in. Maybe the Aussie Blade doesn't need it but that doesn't proof that T-foils are unattractive to the other boats (majority) out there.

And why is it that everytime a new development is discussed we get the "hype" counterargument ?

Now I'll say that I'm deeply impressed by the T-foils after having raced with them a few times on a Stealth. They really do seem like a very simple and cheap improvement for some of our "unoptimized" boats. If you don't need them then the more power to you. Arguably, they can never make a boat more performant then the boat that doesn't need them right ? It is not like we getting them is upsetting the class or giving us an unfair advantage in any way, right ?

Wouter

Wouter,

I seem to recall your boat weighing in at around 123kgs. Ok then thats 18kgs over weight - still a lot of extra weight combined with hulls not designed with spinnaker sailing in mind.?

Ok the Aussie Blade was 111.7kgs - not bad for first attempt. The current boat we are building is currently 108kgs - only 3 more kgs to find without going to carbon mast.!

I dont disagree that you boat is not as F16, but your hulls originally were not & this is the main point.

From first hand experience & discussion with other Blade owners it is clear the two blades are behaing very differently down wind.

I never commented on the t-foils being unatractive - just difficult to operate, maintain & adjust. Not the recommended equipment for first timers.

My personal belief is this group should only push/sell rudder systems that are the standard t-foil arrangement that is currently on the stealth / Alpha F14 and to not make them too complicated - otherwise you will turn prospective F16 sailors away.?

The system you propose sounds too expensive for manufacture & expensive to maintain.

Marcus

Good points Marcus.

In looking at how I sail my boat, the platform angle of attack changes constantly with the conditions. Up wind from a medium condition with flat water, I will drop the nose and try to drive it, while in a blow I will be back with the knuckle out going for speed and foil lift or keeping the beams clear when it is very rough. Foils as currently allowed try to keep a constant attitude. All changes is attitiude including normal wave pitching add drag to the platform. Even if adjustemnts were allowed no human is fast enough to to keep it perfectly alligned while sailing at the speed we go. I have some experience with this and have worked with a number of people who have tried them on larger boats and the reomendation from all is, "good luck if you decide to try"

Wouter, I have to disagree with your push on this issue. Insinuating that the F16 is not optimized without T-foils is BS. I am not saying that they do not work to some extent when developed properly like on the AO14 or the Stealth. I would hazzard to bet though that the fact John was sailing smoother than everyone else in Zaandvort's waves was due to his his sailing skill much more than the fact he had foils on his boat.

For the new sailor anything that is not off the shelf or automatic is a huge distraction to thier learning curve. These boats are complicated enough to drive. You would be a lot better off worrying about driving the boat than constant tinkering with appendages of questionable benefit.

M2C

Matt

I personally feel this subject have been pretty well covered.

It is time for some real world testing boat on boat, or perhaps someone takes a gamble for our next GC? Seeing is believing!

Other opinions on Robis original question

Robi, if you are looking to build up your boat from hulls, do you want to save money or make it somehow "better" than a factory boat, by using different parts?

I think it would be very hard to save money if you have to pay retail for all the parts, most builders get a discount by ordering in bulk.

Rolf,

Having them on a a boat at an event such as the GC would be meaningless as far as an evaluation of their potential benefit.

What is needed to prove in the concept is 2 boat testing with identical equipement and rotation of sailors. Testing over a wide range of conditions and settings.

If I can mange to win the lottery maybe it would be a fun thing to try....Then again if I could spend that much time on the water, I know for a fact that my performance would improve way more than any gain a foil could provide for me.

Matt didn't Darryl do exactly what you are proposing on the F14 A&O with positive proof of the validity of the T-foils?...That is, didn't he do comparison sailing of two identical boats...one with T-foils and one without?

Regards,
Bob

Matt, I agree with what you say.
I think racing gear is darwinistic in its nature. If T-foils are faster, we will see them on more and more boats and at our larger events. If they are not faster, or faster only in some conditions, they will not make it.
Darwinism is based on mutation, and the T-foils certainly are a mutation. If the mutation gives advantages, it will survive, if not it dies. However, if the mutation gives a real advantage, the species with this mutation will do much better in the competition. That's the logic behind the GC comment. Somebody gets it right and launch it in our faces at a GC. Odds are against it, but you never know. Ben Hall tried it at Islamorada with his wing, while the Boulogne brothers won an F-18 worlds in 2003 with their square top main (at least I think that was a big part of why they won). Same for the swedes final position at the 2002 Tornado worlds in Marthas vineyard with their then radically flat spi, which now are the class standard. Sorry for being long winded..

Looking forward to see what Robi has to say on what Timbo asked. I assume Robi is looking for the best possible boat within budget?

How many attempts do you think I invested in my F16 ? <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />





Ohh I understand now Marcus, you are refering to a setup I placed on this forum several months back. In this thread I'm just talking about permanently fixed T-foils to a standard EU Blade rudder board. Basically the angle of attack of the T-foils is set to somewhere between -2 and 0 degrees with the boat right on its optimal waterline. So when the boat is sailed at low speed or on its waterline then the T-foils won't add much drag at all. There are no moving parts anymore, the two screws used to fit the T-foil to the rudderboard are also used to fine-tune the angle of attack to the -2 to 0 degrees range. Ones set up the gaps are filled with filler and resin and the whole setup is fixed.

I don't see this as very expensive or difficult to manufacture. It is basically the standard EU Blade rudder boards with a T-foil bolted to its tip. It uses all the same hardware as the conventional rudder would.

Wouter

I actually raced a F16 with T-foils a few times and I know what kind of difference they can make. I've done some extensive modelling on them and again the benefits for my boat are undeniable.

Basically I know what I know and these T-foils are allowed in the F16 class, so what's up !

Besides I don't think there is any rule preventing tinkerers like myself from posting their thoughts, experiments and showing their enthousiasm. If that is intepreted by others as "pushing a concept" or "insinuating that F16's are not optimized" then that is really not a fault on my part.

If I hadn't tinkered with the 3-stage cascading internal downhaul then we would still be pulling our arms out with little sail response. Hell, we wouldn't even have a F16 class at all.

Sorry guys, I think we are getting a little bit to tight in our mindsets here.

Wouter

This thread turned to crap because of all the T foil chatter.

I am not getting T foils because of various reasons. The main reason is the exchange rate does not make this an attractive upgrade to consider, unless of course I win the lotto but first I would have to play to win.

Robi, back on topic, re. the title of this thread; you might want to check with the F16 builders for parts, they might sell them to you for what they pay when they buy in bulk, and then you can put your boat together how you like.

But Robi, what are you really looking for? Ultimate boat or a less costly boat? Or??

Tim those are my intentions. Hopefully this boat will be ready for St Patrick's day.

Not ultimate or less costly but mostly personalized. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" /> Cost is no factor up to certain point.

A Landenberger main is extremely expensive due to the exchange rate. I am still waiting on a local US distributor to see how much more or less it will cost me to purchase such a mainsail.

-Hopefully??- You had BETTER have that thing ready by St. Patrick's Day! It's going to be a big F16 regatta in your own back yard!! So, what are you going to build? Blade hulls? Carbon mast? Call Jay Glasser for a new main.