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Re: Foilcats [Re: Dean] #30847
03/22/04 01:34 PM
03/22/04 01:34 PM
Joined: Jul 2001
Posts: 800
MI
sail6000 Offline
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MI

good posts Dean --thanks

or rab zeppelin

http://users.wolfcrews.com/toys/vikings/

have fun

-- Have You Seen This? --
Re: Foilcats [Re: Luiz] #30848
03/22/04 02:11 PM
03/22/04 02:11 PM
Joined: Sep 2003
Posts: 270
Nepean (Ottawa) Ontario Canada
Frozen Offline
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Nepean (Ottawa) Ontario Canada
Whoa! I can see it now....

This is your Captain speaking.... uh what was that booming sound.... Uh gee I guess that was some of the hydrogen filled skin in the area behind the engines.. The tail just blew off.

Uh sorry I couldn't resist...


Cheers
Alan F

Tiger
Re: Foilcats [Re: BRoberts] #30849
03/22/04 02:33 PM
03/22/04 02:33 PM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
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First, fixed foils won't work/fly. The foils have to be modulated because the weight to lift is constant but the ability to generate lift increses with the speed of the boat squared. Once a craft is foilborn and accelerating something has to control the lift or else the lift will continue to increase until the foil stalls and then crash. Once a foil craft climbs up on its foils something has to keep the total foil lift constant as the craft changes speed while up on the foils. This is acheived by changing the angle of attack of the entire foil or by varying a trailing edge flap on the foil to control lift. The secret to foil boats is not the foil shape; it is to "control the foil" to generate constant lift, boat plus sailor, over a useable speed range.


Bill,

This is correct if the goal is to sail the boat fully "foilborne" - to fly supported solely by the foils.

If the goal is to reduce wetted surface, fixed foils designed to lift less then the total vertical load seem to work fine. At least this is the way I understand they work in the Open 60 tris (up to 20 to 30% lift) and in the Catri (up to 90% lift).

But maybe things work different then I understand, and in this case I look forward for today's lesson!

Cheers,
Luiz


Luiz
Re: Foilcats [Re: sail6000] #30850
03/22/04 02:54 PM
03/22/04 02:54 PM
Joined: Sep 2003
Posts: 270
Nepean (Ottawa) Ontario Canada
Frozen Offline
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Nepean (Ottawa) Ontario Canada
Someone asked what water temps we get here in Labrador.

I asked our Environmentalists and here is the reply.


"The maximum we recorded was 16.5,( July 29, 1982) during late July to mid August, the average is lower though, around 14.5."

(16.5 degrees Celsius is around 62 degrees Fahrenheit
14.5 is around 58 degrees)

This temerature is usually within a couple degrees (less) of the monthly
average temp taking lag time into consideration."

But... We don't get hurricanes


Cheers
Alan F

Tiger
Re: Foilcats [Re: MauganN20] #30851
03/22/04 05:46 PM
03/22/04 05:46 PM
Joined: Aug 2003
Posts: 284
S. Florida
BRoberts Offline
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S. Florida
Hello Maugan,
Of course I have. I referred to the two control schemes in production without saying their names, Hobie Cat and Rave. I just wanted to be sure I didn't step on anybody's toes so I didn't use any company names.
By the way, the wands do not control pitch angle; they control lift by varying a trailing edge flap. The scheme with the water ski out front controls lift by varying foil angle of attack.
Bill

Re: Foilcats [Re: Dean] #30852
03/22/04 06:12 PM
03/22/04 06:12 PM
Joined: Aug 2003
Posts: 284
S. Florida
BRoberts Offline
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S. Florida
Dean,
The "one time" that the Rave class participated in the Miami to Key Largo Race is not the only time that a Rave has sailed in the race. Sam Bradfield's 27ft test boat also has sailed in the Miami to Key Largo Race.
As to the new boat: Nigel Irens built the boat and Sam Bradfield did the Foils. I wish them much success. Sam deserves it.
Bill

TriFoiler "Old Technology?" Still Fast Though... [Re: Dean] #30853
03/22/04 06:23 PM
03/22/04 06:23 PM
Joined: Jun 2001
Posts: 1,252
California
mmiller Offline
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mmiller  Offline
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Posts: 1,252
California
[Linked Image]

All this talk about joy sticks controlling the foil angles and bad sailing angles. I'd guess the "H" for Hobie Trifoiler (old technology? as DEAN says) still isn’t that bad, being "old technology". Patented “old” technology by the way.

The TriFoiler still holds the A Class World speed record at 50.1 MPH.

A Class Russell Long (USA) 43.55 knots July 1992 Tarifa, Spain

Speed Records

It is really easy to sail, kind of like driving a car... just steer. At 10 kts (of course on flatter water is easier) you can get up. If there is 10-12 kts you can hardly keep it off the foils. I have seen the Rave in windier conditions not even on the foils and when "on the foils"... more like dragging it's butt.

Greg (Ketterman) was out this weekend sailing a couple miles offshore of Long Beach Harbor. He was in 15-18 kts of wind, in rough water, and getting onto the foils sailing 60-70 degrees off head to wind… (going upwind). Once on the foils it sailed at 55-60 degrees and, he says, will do 50-55 degrees in optimum conditions (more wind and flatter seas). The VMG is still way better that most any fast cat. He sailed with Randy Reynolds on his 33’ and could pace him upwind... and do circles around him down wind.

From my own experience, the TriFoiler sails upwind at a lower angle than a Hobie 20, but way faster even with 2 people onboard, I was able to keep up with a fleet of 20's racing in rough water going upwind in Long Beach a few years ago. At the weather mark...Yikes!.. when we turned the corner... it was SCARY fast passing them at 2-3 times their speed and able to go much, much deeper! All without thinking about foil angles... it is all automatic on the Hobie TriFoiler.

Yes the TriFoiler is technical and not built like a Hobie 16, but it is made for speed right? It is still pretty rugged though. Most problems anyone has had has been due to rigging and handling errors as well as sailing in rougher and very windy conditions.

On this one, we did not try to accommodate the average sailor and all conditions as the Rave has tried to do. The Hobie TriFoiler is all about speed. If you want to sail displacement... sail a Cat.

There is some interesting history of the TriFoiler development on the Hobie Cat website at:

TriFoiler History

Here is a link to some arial video that shows the foil and sensor system at work:

Arial footage

Greg hasn't given up on foils yet. It is still his passion.


Hobie Cat Forums
Matt Miller
Hobie Cat Company
Re: TriFoiler "Old Technology?" Still Fast Though... [Re: mmiller] #30854
03/23/04 09:52 AM
03/23/04 09:52 AM
Joined: Aug 2002
Posts: 277
Baton Rouge, LA
Dean Offline
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Dean  Offline
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Baton Rouge, LA
[quote] I guess the "H" for Hobie Trifoiler (old technology? as DEAN says) still isn’t that bad, being "old technology". Patented “old” technology by the way.[unquote]

Hi, Matt,

First, if no one reads anything else, read this: The Tri-Foiler sells for $14,000. The Rave goes for $10,000. For that $4,000 less you can have a Rave and a used catamaran; the best of both worlds. Now for my rebuttal.

NO,no,no, I said it was "early technology" and it is. My response was to contrast the robustness of the Rave's durable design to the fragility of the skids on the Tri-Foiler and to imply that the Tri-Foiler's early technology with the skids was improved upon by the Rave's system of T-Foils automatically controlled by the wands. I've also said that the skids forward of the bows are not good in a chop and they are not. To sail on a chop you need longer T-foils and an automatic leveling system, the Rave's wands, that does not depend upon a relatively smooth water surface as does the Tri-Foiler's skids.

But, I am glad that you and I both have pointed that this is a moot point because at 10-12mph you're up on the foils in the Rave or the Tri-Foiler. Most, if not all, sailors unfamiliar with foiling assume that you have to have a lot of wind, typical for a light chop, to get the craft out of the water and that's just not the case. Perception and rumours die hard. Some, incredibly, have the impression that foils produce so much drag after liftoff that it brings the boat down. (That was a new level of incredulity. I can only assume he doesn't fly in a plane for fear of it falling out of the sky after takeoff.) I can't emphasize enough that the move from understanding vertical foils moving at a slow speed to the science of horizontal foils at much faster speeds is a whole 'nuther ball game. Cat sailors, for example, do not have to be concerned with the foils moving so quickly that it can literally vaporize the water moving aross the foils' surfaces.

Matt, your observation is correct in saying that the Rave tries to be more of an all-around boat than the Tri-Foiler. That was a marketing decision that seemed to logically follow the boat's basic design. That's not better or worse. It's just different. As Hobie has discovered going to the more pure market was no better than going to the broader market. Neither boat has made much of a dent in the water.

They're all good for what they are. Some sailors would like to keep their cat but hang out the foils at times hence Dave Carlson's clever solution. I've seen Dave's boat foil. Others may want only a strictly foiling experience for which the Tri-Foiler is made. The Rave is a good weekend daysailer with some space to haul what you need from place to place. The bottom line is that, unlike beachcats which pretty much offer the same sailing experience, the foilers all achieve flight in different manners and the owner should choose the personality that he wants to live with when his foiler is sailing only as the amiable Dr. Jekyl. They all offer the Mr. Hyde hair-on-fire experience.

One thing all the production foilers have in common is an incredible lack of promotion. These exciting water craft are all but hidden from the larger market. That's a disappointment and with all the talk of guys who say they love speed, when the money hits the table they go with what they know. Kinda like monohullers when cats were new. Actually, I'm just picking on you. If you want to go fast more of the time a cat is the way to go but please don't look down on me out there on the fringe where lesser cajones fear to tread.

Re: TriFoiler "Old Technology?" Still Fast Though... [Re: Dean] #30855
03/23/04 11:39 AM
03/23/04 11:39 AM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
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Luiz  Offline
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Asuncion, Paraguay
Quote
One thing all the production foilers have in common is an incredible lack of promotion.


Both Catsailor and Multihulls Magazine have always featured foilers. But new things take their time to be accepted. Even refrigerators had to be advertised before people would buy them.

Cheers,


Luiz
Re: Foilcats [Re: BRoberts] #30856
03/23/04 11:44 AM
03/23/04 11:44 AM
Joined: Apr 2002
Posts: 805
Gainesville, FL 32607 USA
dacarls Offline
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dacarls  Offline
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Gainesville, FL 32607 USA
Addressing Bill Roberts paragraph post of last week "fixed foils won't work...". I've got Doran Oster and Bill both fussing at me now in the same week! I agree that fixed surface-piercing foils are always in a dynamic situation, with everything changing all the time- variable lift, driving force (wind), drag, heeling angle, fear of crashing in the driver's heart, etc....

But this is the reason for the tapered surface-piercing foils as seen in the old Icarus I photos from the 1970s, and now the 36 foot Spitfire biplane foiler from Perth. The question that I see is- can I buld a modern tapered shape that will avoid some of the disadvantages of previous shapes. Bill Roberts and Doran- and Dr. T-foil (Sam Bradfield)- say it's hopeless. BUMBLEBEEs fly anyway...despite what the engineers said years ago. BTW- High speed photos of insect flight are absolutely amazing, with flexible (plastic) wings, superflexible joints and vortices. Well, that nails the name for my next foiler.


Dacarls:
A-class USA 196, USA 21, H18, H16
"Nothing that's any good works by itself. You got to make the damn thing work"- Thomas Edison
Re: Foilcats [Re: dacarls] #30857
03/23/04 12:40 PM
03/23/04 12:40 PM
Joined: Aug 2002
Posts: 277
Baton Rouge, LA
Dean Offline
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Dean  Offline
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Posts: 277
Baton Rouge, LA
Dave,

Bumblebees do not fly. They float. They are sprayed with magic dust. You can see it on their feet. They also have a little rocket that is visible in their tail. I've had one deposited in my thumb. It's really tiny.

Re: Foilcats [Re: dacarls] #30858
03/23/04 01:37 PM
03/23/04 01:37 PM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
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Luiz  Offline
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Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Quote
...this is the reason for the tapered surface-piercing foils as seen in the old Icarus I photos from the 1970s, and now the 36 foot Spitfire biplane foiler from Perth. The question that I see is- can I buld a modern tapered shape that will avoid some of the disadvantages of previous shapes...


I once asked Aldis Eglajs about the Australian Spitfire. All he commented is that progress is very slow and that the Spitfire is 99% the same as James Grogonos last Icarus concept, before 1987. He implied that this type of design works, but has some conceptual limitations.

Are you spending your time in a dead end? I don't know enough for my opinion to be relevant, but I know there are many concepts to investigate and very few people doing the ressearch, so go ahead!

Oh, yes: there was a big boat called Bumblebee some 25 years ago. I think it was South African.

Cheers,


Luiz
early technology... [Re: Dean] #30859
03/23/04 01:39 PM
03/23/04 01:39 PM
Joined: Jun 2001
Posts: 1,252
California
mmiller Offline
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California
DEAN...

OK, early technology... but likely still the best technology available for self-leveling the foils. Greg has tried a lot of different things.

You are certainly wrong about the forward sensor system not working in chop. Yes, it does… and well. I can only assume that you have never actually seen a TriFoiler. We quote the same chop limitations as pretty much all of them. 2-3 foot close chop is the limitation of the foil height as the wave peaks slap the bottom of the hull and slow it down. Swells are no problem; so open ocean sailing is practical as expressed in my earlier post.

The sensor forward design is COMPLETELY automatic self-leveling. Yes the forward sensor takes a beating (you can see it in the videos), but it is "forward thinking" rather than reacting to what has already passed the foil area. That makes allot more sense… and as said before, it is patented. That is the primary reason it is not used on other boats.

I would imagine that you actually have never been on one and possibly never actually seen one sailing? Otherwise, you would appreciate that it is SMOKIN’ fast and very fun to sail, easy to handle and rock solid on the foils. There is no up and down porpoise action, no healing. It is on the foils through jibes and nearly through tacks. A novice can sail it, it is that simple and easy to control on the foils... just steer.

I think I understand your motives, but please try and stick to facts and try not to slander other systems as a way of justifying or supporting your favorite one.

As far as some perceived lack of promotion, the TriFoiler has gotten tons of press and National TV exposure over the years. You can see many of the print articles on the TriFoiler history page on our site. These things are not like refrigerators… not everyone needs one. There are many limitations, so they continue to be of interest only to a select group of people.

By the way, Greg would love to try a Rave sometime. I am sure he is up for a boat swap for some fun comparison sailing. He can meet with an interested Rave (or other foiler) sailor, with boat, in the Long Beach, California area.


Hobie Cat Forums
Matt Miller
Hobie Cat Company
Re: early technology... [Re: mmiller] #30860
03/23/04 02:43 PM
03/23/04 02:43 PM
Joined: Mar 2004
Posts: 1
D
Dwayne Offline
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Dwayne  Offline
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Joined: Mar 2004
Posts: 1
Hi I'm a RAVE owner, just purchased my boat about a month ago. I have NEVER sailed a multi-hull, not cat or tri until I sailed my own boat. On my first day with winds between 10 and 15 knots I was able to get up on foils within 20 minuits. My first foil was not long just a few seconds but as the 4 hour playtime progressed I had a run of about 30 seconds, the only reason it was not longer was I was running out of lake to fly on! Being on foils is a hoot! I have no idea how fast I was going as I don't yet have a GPS to tell me but I was keeping pace with a powerboat at one time and he was booking to his fishing ground.

What I am trying to say is that the RAVE is very easy to use, it took me about 35 minuits to setup and would have been faster if I would not have lost a part on the drive to the lake.

As far as tweeking, adjusting etc, I set the tension on the bungie's one time, I must have gotten it correct for my conditions because I NEVER touched them again, so that only left the normal things a sailor has to deal with, the main sheet and the jib sheet, and stearing. Since the RAVE uses your feet to stear I had one hand for each sheet. I never adjusted the joystick, so just left the rear foil in the nutral position, from what I understand this is really only there to try and get the RAVE out of the water faster so I didn't play with this feature either.

It was simple, have enough wind (12 knots and up), get the correct heading (can't fly too close to the wind), adjust sails, and have enough water and you are off! The enough water is both in depth and distance because once you are up on foils you are moving!

Going fast is fun, but so is sailing in general so even if you are not up on the foils you are out, about, and messing around with a boat!

BTW I only paid 6K for my RAVE, that included the reacher and trailer, it's a 2001 model but I am the first owner.

Dwayne

Re: early technology... [Re: Dwayne] #30861
03/23/04 04:19 PM
03/23/04 04:19 PM
Joined: Aug 2002
Posts: 277
Baton Rouge, LA
Dean Offline
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Dean  Offline
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Posts: 277
Baton Rouge, LA
I've re-read my post up there and it doesn't sound mean to me. In fact, it is in praise of foilers in general and that is the point I am trying to make: They can't be beachcats and foilers all-in-one and that's okay.

Au contraire. I've seen and touched one. He sailed below Melbourne, FL. I've seen him very seldom and checked-out his boat on the beach. That's the only one I've seen. Are other Tri-Foilers different? There are a bunch of Raves in central Florida but I've only seen one Tri-Foiler. That's not a cut. It's simply what I've observed over the last five years. There aren't many of either boats around.

As for my "motives" you are assuming that I am a die-hard one boat dogmatic believer. I have three boats that keep me hoppin'. I love them all for what they do. Quite to the contrary I can appreciate different designs but I happen to think that one design has advantages over another and I personally believe the Rave is the all-around more durable design.

Regarding forward thinking as opposed to what already has past the foil area, the wands on the Rave are directly above the foil area so there's no delay in what the foil is experiencing as you implied. That's hard to miss if you've seen one.

Regarding slanderous comments, Jeez, this is a casual forum for a bunch of casual sailors. To quote the Lone Ranger, "Whoa, big fella". The parrot on your shoulder wasn't the only one that took the L.S.A.T. This is a discussion with opinions and,like you, everybody has one.

If you want a test ride go to Windride.com for the location nearest you but I would have thought that you would be intimately familiar with the other products on the market. Unlike the regattas, this isn't Hobies Only.

Re: early technology... [Re: Dean] #30862
03/23/04 06:07 PM
03/23/04 06:07 PM
Joined: Jun 2001
Posts: 1,252
California
mmiller Offline
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mmiller  Offline
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California
DEAN...

Now… who needs to loosen up? Nope, there are no ties to loosen. Not that kind of work place and don't worry about our team of company lawyers, they don't follow the Catsailor forums.

Since you are experienced with the Rave, go ahead and share that. But, my point is, please don't portray yourself as having some experience with another product or system when you don't. There is just too much of that on these forums. When I read stuff, like you wrote, I just HAVE to jump in and set the record straight… and that isn’t even in my job description!


Hobie Cat Forums
Matt Miller
Hobie Cat Company
Re: early technology... [Re: mmiller] #30863
03/23/04 06:13 PM
03/23/04 06:13 PM
Joined: Aug 2002
Posts: 277
Baton Rouge, LA
Dean Offline
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Dean  Offline
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Posts: 277
Baton Rouge, LA
I understand completely. Truce. I hate feeling like this. I actually lose sleep when someone I don't even know thinks I'm a jerk.

Re: Foils and A cats... [Re: Dean] #30864
03/23/04 08:17 PM
03/23/04 08:17 PM
Joined: Jul 2002
Posts: 206
Yardley PA
DanWard Offline
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DanWard  Offline
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Yardley PA
As I understand it, the A cat class has decided against allowing foils (defined as being able to lift the hull clear of the water). This would appear to leave the door open for the variety used to partly lift the boat as on the Catri to reduce wetted area. I have been waiting to see if they showed up on any new A cat designs but as far as I know no body is doing it. Given the A class passion for innovation there must be a good reason they are passing on this one. The cons must be outweighing the pros. I assume it must be the light air penalty. Do any of you technical guys care to comment?

Re: Foils and A cats... [Re: DanWard] #30865
03/24/04 01:35 AM
03/24/04 01:35 AM
Joined: Feb 2004
Posts: 1,012
South Australia
Darryl_Barrett Offline
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Darryl_Barrett  Offline
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Posts: 1,012
South Australia
The "A" class rules and regulations are always "under review" and any new innovation is looked at, on a internatonal global level, discussed at length, either put up for approval, or discarded, if put up, voted on, accepted into the class or else rejected. Theirs is a system that has served them extremely well for 40 odd years and has kept the class active and progressive (even through the times of depression within the sailing community) They rejected "solid winged sails/mast" when there was quite a strong move in that direction, and it has proved to be the right decision for the class, as well as countless other minor and majour changes. I am quite sure that they have viewed the "International 14'" (formally 14' skiff's in Australia) very closely as that class has embraced the "T" foil on a variable angled rudder that has enhanced their performance considerably (the foil has also been used on their dagger board and the final configuration still has to be evolved) The moths are another class that uses a full lifting foil on their dagger board which lifts the hull completely out of the water (but is usually sailed without foils when the wind gets up a bit, as one champion moth sailor said "it isn't pretty ditching a moth travelling at 25 to 28 knots in 15 knots of wind, and it hurts!" Personally it would surprise me greatly if the "A" class cats incorporated foils into the class when they perform so well now as well as so close to the "edge".
Darryl J Barrett

Re: Foils and A cats.& speed sailing machines.. [Re: Darryl_Barrett] #30866
03/24/04 11:39 AM
03/24/04 11:39 AM
Joined: Jul 2001
Posts: 800
MI
sail6000 Offline
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sail6000  Offline
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Posts: 800
MI

Good comments -

Think the A class rule reads to the effect that no part of the boards or rudders can extend beyond the 7.5 ft beam limitation ,-in effect -no canted boards or foils.

The A s {a limited development class}- are the ideal small cat and hope they maintain that goal ,-the design measurement rule has produced beautifull refined cat designs .
good recent example http://www.morrellimelvin.com/sailboats.html

An ideal lifting design would have much larger overall beam for stability -like the Aussie foiler -with approx. 75% beam to l ratio of hulls and equal L to B Ratio w foils .http://marine.bdg.com.au/spitfire12.html

A interesting promising speed sailing craft from the UK is
this one http://www.whbs.demon.co.uk/sr2/content_fr.htm

Most of these speed machines are proa types ,-their primary design function -to sail beyond 50 knots in one direction on smooth water .

The interesting aspects of Sail rocket are its canted sail
{providing lift } and its main hull configuration being full at the bow and stern with the center area being above the waterline .

This type of hull design applied to a cat configuration with retractable foils may be an area of design pursuit , the other key features being light weight .-large beam to L ratio ,-and canted sail plan .

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