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Re: Rudder gantry [Re: ] #159755
11/06/08 04:06 PM
11/06/08 04:06 PM
Joined: May 2003
Posts: 4,451
West coast of Norway
Rolf_Nilsen Offline

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Rolf_Nilsen  Offline

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Glad you saw my comment that way smile

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Re: Rudder gantry [Re: Rolf_Nilsen] #159758
11/06/08 04:41 PM
11/06/08 04:41 PM

S
Scarecrow
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Scarecrow
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S



Email has been sent to Hans and John with this and many other questions.

Re: Rudder gantry [Re: ] #159771
11/06/08 07:18 PM
11/06/08 07:18 PM
Joined: Oct 2005
Posts: 951
Brisbane, Queensland, Australi...
ncik Offline
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Actually the standard and low cost bladeriders are going to aluminium gantries. Stated as being stronger and stiffer than the current carbon version. Not sure what the high-end version is having though.
http://www.bladerider.com.au/xseries/rx.html

Re: Rudder gantry [Re: ncik] #159799
11/06/08 11:17 PM
11/06/08 11:17 PM
Joined: Jul 2002
Posts: 539
taipanfc Offline
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High-end version using the same gantry as the original X8 version.

Re: Rudder gantry [Re: taipanfc] #159804
11/07/08 12:09 AM
11/07/08 12:09 AM
Joined: Oct 2005
Posts: 951
Brisbane, Queensland, Australi...
ncik Offline
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Stiffness is something you'd want back there and if the aluminium version is stiffer, maybe they are keeping the shape of the carbon one but modifying the layup/structure.

Only guessing though.

Re: Rudder gantry [Re: ncik] #159809
11/07/08 12:33 AM
11/07/08 12:33 AM
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Posts: 539
taipanfc Offline
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Stiffness is due to people capsizing and holding onto the tiller rather than letting it go. So in a number of occasions the whole gantry has twisted off as the boat goes over. Since the 2 lower models are aimed at new moth sailors, this extra stiffness minimises this happening and warranty claims.

Re: Rudder gantry [Re: taipanfc] #159813
11/07/08 04:33 AM
11/07/08 04:33 AM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
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Quote

So effectively having the gantry begin say an inch above the stern and having "buoyant qualities".


At a certain point the ever expanding gantry will effectively become an effective lengthening of the waterline (bouyancy) and no longer only acts as a hing point for the rudders (because it is also providing additional bouyancy).

The class can easily combat this wild growth however by requiring that the gantry has large openings that allow water in. This won't affect the hinge point of the rudders but make its bouyancy contribution negligiable.

There is another thing about open class rules. Not everything can be allowed or disallowed in detail as you never know in advance what creative minds can think up in the future.

However the intent of the rule is very clear, the pintles are excluded from the hull measurement when their only function id to provide a hinge point for the rudder boards, this does NOT enclose providing additional bouyancy or lengthing of the waterline. If it does so then it will be included in the hull length measurement. Note that the position of the hinge point is NOT regulated and therefor maybe anyway where you want it to be and therefor allow REAL gantries (and not hull extentions renamed as such). You could even put the rudder boards directly under the bow of the hull if you think that will give better hydrodynamic behavior. That is with a axle going through the deck and front portion of the hull and steer just like a car.

Additionally the other rule, about spirit of the rule set is very clear also, increasing the distance between the boards is NOT a (significant) performance enhancing feature. It may be a refinement of how the boat feels c.q. handles but that is explicitely allowed by rules 2.6.2 a, 2.6.2 b and 2.6.2 c !

Of course I too refer to the TC on this topic, as that is the official route, but I do really believe a very strong argument for the use of true gantries can be had. If the TC for some reason disallows it then I'm really interested in how they square that with the F16 class rules !

Wouter

Last edited by Wouter; 11/07/08 04:50 AM.

Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: Rudder gantry [Re: Wouter] #159815
11/07/08 05:22 AM
11/07/08 05:22 AM
Joined: Jul 2007
Posts: 976
France
pepin Offline
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France
I would agree with wouter here. As long as:

- There is no lengthening of the waterline
- There is no added buoyancy

I don't see why it should be disallowed.

The gantry pictured at the top of the thread provide buoyancy, so should be disallowed. Poke big holes in it, it no longer provide buoyancy and it should be allowed.

Re: Rudder gantry [Re: Wouter] #159866
11/07/08 10:54 AM
11/07/08 10:54 AM
Joined: Aug 2005
Posts: 221
Netherlands
Hans_Ned_111 Offline
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Posts: 221
Netherlands
From the F16GC

The GC has done its best to negotiate an amicable solution over internet domains. Unfortunately a fair & reasonable solution has not been reached to date.

Wouter, you have not been "excommunicated" from the class. You have chosen not to join it.

Since this is an important matter for the class, the GC directs the members to discuss this topic on the members forum where it is hoped that a reasonable solution for all parties can be reached.

Best regards,

Hans Klok
Chairman F16 Governing Council


Best regards,

Hans Klok

Web : http://www.catamaranparts.nl
Blog : http://catamaranparts.blogspot.nl
Mail : info@catamaranparts.nl

Raptor F16 and A-class builder
Re: Rudder gantry [Re: Hans_Ned_111] #159871
11/07/08 11:11 AM
11/07/08 11:11 AM
Joined: Jul 2002
Posts: 539
taipanfc Offline
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So can someone collect the toys thrown out of the pram? They are tripping people up and stopping them from moving forward.

Re: Rudder gantry [Re: Hans_Ned_111] #159884
11/07/08 01:53 PM
11/07/08 01:53 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
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Wouter  Offline
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In reply to the post made by the chairman of the GC.

Here is my reply to the comments made and I expect it to be my last in public barring any spectacular new developments or the announcement that the issue is resolved.

This posting is the first time that I'm officially spoken to by the GC about the ownership issue relating to the URL's (or even the other stuff).

All other communication was through back channels and informal in nature and I never discussed any proposal or even anything relating to the ownership with the chairman, the secretary or the threasurer directly. In fact I have only communicated with one person out of this group, who happens to be a long time friend of mine, but on personal titles only.

In all seriousness, officially I have never spoken with the GC about this topic and indeed this is the first time that we do. As such I have never negociated directly with the GC. I truly wonder how this can be seen as "Doing its best".


However, I do indeed underwrite the following statement :

"Unfortunately a fair & reasonable solution has not been reached to date."


Furthermore, it is said that I've not been excommunicated from the class but have chosen to not join. In fact, both parties are guilty of hyperbole here. Indeed I'm not excommunicated in the direct sense, that was an overstatement on my part. If I pay for the membership I will be granted one, but I hold no illusions on ever being called upon for advice. However, my "choice" not to join is subject to clearification as well. In fact, I do consider myself a creditor to the F16 class (the GC) by paying for some of the internet resources they use. In return I asked to be credited by the GC by means of granting me a class membership. I pay in real money for something they use and they were asked to pay me back in awarding me a membership. Effectively this entlarges their budget as the expenses for these resources are higher then the membership fee. In monetary terms, they gain more then they loose. Not an unimportant aspect of the situation considering the class has only just build up a paying membership structure and won't be creating a huge annual income yet. I do confess to naively believing the GC would jump to such an offer.

Of course "joining by payment" during these "negociations" would only make my own position irrelevant. Probably ending up in me paying for the resources AND the membership. Not something a party in such a proces does. I would like to underscore here that the "negociation" stalled and I had to renew my ownership of the resources. So it is no longer an option that the GC pays for this bill themselves even if I were transfer the owner rights to them now. The alternative would have been to let it lapse and risk Macca (or some other party) claiming it and doing a victory dance in public. It does surprise me that the GC were willing to take this risk with a rather important class resource. Actually, this is one of the reasons why I've hung to these resources over the last years. I will only transfer these to a party that is dedicated to the F16 class and that has proven to be dependable. Needless to say that I will never allow it to lapse or allow it to fall in the hands of parties undedicated to the F16 class. If ever the new owner lets them lapse for a single day then I will reclaim them. This is not a threat but rather a promise. We (all of us in the F16 class) can simply not risk these resources falling into the wrong hands.



You also state that :

Quote

Since this is an important matter for the class, the GC directs the members to discuss this topic on the members forum where it is hoped that a reasonable solution for all parties can be reached.



Since I'm not a class member I can't go to this members-only forum and help solve this issue. I too hope that a reasonable solution can be worked out overthere but with one of the parties (= me) being absent I do question the effectiveness of this approach.

Now I know that a possible argument back could be that I "chose" not to be a member and that therefor I can only blame myself. However, I refer any people with such an opinion to the fact that my class membership is in fact a key part of the "negociation". By this reasoning we have just entered what many call cyclical reasoning.


Now, truly with all due respect, I'm tired of going around in circles on this issue.

The situation is really is not that hard to solve.

Everybody now knows what's on the table and we can just as well communicate by private e-mail.

I too deplore the way things have gone down and indeed I too see a reasonable resolution as in the best interest of the F16 class.



With kind regards,

Wouter Hijink

F16 class founder.

Last edited by Wouter; 11/07/08 02:02 PM.

Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: Rudder gantry [Re: Wouter] #159899
11/07/08 05:21 PM
11/07/08 05:21 PM
Joined: May 2006
Posts: 954
Mumbles Y.C Wales U.K
Mark P Offline
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Mumbles Y.C Wales U.K
Thanks..... It's time to move on


MP*MULTIHULLS
Re: Rudder gantry [Re: Mark P] #159900
11/07/08 05:26 PM
11/07/08 05:26 PM
Joined: May 2006
Posts: 954
Mumbles Y.C Wales U.K
Mark P Offline
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Mark P  Offline
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Rudder Gantry?


MP*MULTIHULLS
Re: Rudder gantry [Re: Mark P] #159921
11/07/08 11:06 PM
11/07/08 11:06 PM
Joined: Sep 2006
Posts: 586
Hobart, Tasmania, Oz.
Dazz Offline
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Dazz  Offline
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Hobart, Tasmania, Oz.
n. pl. gan·tries
1. A mount for a traveling crane consisting of a large archlike or bridgelike frame designed to move along a set of tracks.
2. A similar spanning frame supporting a group of railway signals over several tracks.
3. Aerospace A massive vertical frame structure used in assembling or servicing a rocket, especially at a launch site.
4. A support for a barrel lying on its side.


C2 AUS 222 by Goodall design
"Darph Bobo"
Re: Rudder gantry [Re: Dazz] #159931
11/08/08 10:42 AM
11/08/08 10:42 AM
Joined: Oct 2007
Posts: 199
Constanta, Romania
isvflorin Offline
member
isvflorin  Offline
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Posts: 199
Constanta, Romania
So Scarecrow,
are you adding rockets to the transoms or what ?


Sorry, just couldn't resist... grin

Last edited by isvflorin; 11/08/08 10:42 AM.

Florin
Re: Rudder gantry [Re: pepin] #159932
11/08/08 11:13 AM
11/08/08 11:13 AM
Joined: May 2002
Posts: 1,037
Central California
ejpoulsen Offline
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Central California
Originally Posted by pepin
I would agree with wouter here. As long as:

- There is no lengthening of the waterline
- There is no added buoyancy

I don't see why it should be disallowed.

The gantry pictured at the top of the thread provide buoyancy, so should be disallowed. Poke big holes in it, it no longer provide buoyancy and it should be allowed.


I can envision a benefit of a lengthened gantry when using the T-foil rudders like the Stealth has as it could increase the anti-pitch leverage. I think this should be allowable if someone wanted to try it.

However, there is another type of foil rudders that could be a problem...Some of the skiffs have a long rudder gantry and a large foil that is not located at the bottom of the rudder, like John P's, but rather at the waterline. Some of these are adjustable on the fly; others are fixed. These foils can help stabilize the boat's attitude but can also act to increase the effective waterline, which should not be allowed in the F16 class.

Attached Files
I14tfoil4.jpg (271 downloads)

Eric Poulsen
A-class USA 203
Ultimate 20
Central California
Re: Rudder gantry [Re: ejpoulsen] #159956
11/08/08 06:46 PM
11/08/08 06:46 PM
Joined: Oct 2005
Posts: 951
Brisbane, Queensland, Australi...
ncik Offline
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ncik  Offline
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Brisbane, Queensland, Australi...
Originally Posted by ejpoulsen

can also act to increase the effective waterline,


And how does this benefit small, light and fast boats like the 14 and F16 which are well beyond the displacement speed range?

Re: Rudder gantry [Re: ncik] #159961
11/09/08 12:56 PM
11/09/08 12:56 PM
Joined: Feb 2004
Posts: 3,528
Looking for a Job, I got credi...
scooby_simon Offline
Hull Flying, Snow Sliding....
scooby_simon  Offline
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Originally Posted by ncik
Originally Posted by ejpoulsen

can also act to increase the effective waterline,


And how does this benefit small, light and fast boats like the 14 and F16 which are well beyond the displacement speed range?


Helps to prevent pitchpoles


F16 - GBR 553 - SOLD

I also talk sport here
Re: Rudder gantry [Re: scooby_simon] #159964
11/09/08 02:29 PM
11/09/08 02:29 PM

S
Scarecrow
Unregistered
Scarecrow
Unregistered
S



Dazz,

just to confirm the gantries will or course be for holding the railway signals. Where do you put the signals on your boats?

No I won't be fitting T'foils or any other horizontal component to the rudders as on a well designed (and sailed) 16' cat I believe the negatives far out way the positives.

Re: Rudder gantry [Re: ] #159965
11/09/08 03:04 PM
11/09/08 03:04 PM
Joined: May 2003
Posts: 4,451
West coast of Norway
Rolf_Nilsen Offline

Carpal Tunnel
Rolf_Nilsen  Offline

Carpal Tunnel

Joined: May 2003
Posts: 4,451
West coast of Norway
Just to straighten my own head, is the DS16 going to be designed as an F16?
I seem to remotely remember a previous discussion about the DS, but I dont remember the details.

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