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Re: spinnaker draw height [Re: john p] #718
07/27/01 07:34 AM
07/27/01 07:34 AM
Joined: Jul 2001
Posts: 344
Arkansas, USA
Kirt Offline
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Kirt  Offline
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Arkansas, USA
John (and others?)-
<br>How comfortable do you feel just raising "draw height" on your current mast (which of course will also allow you to increase sail area)? Your post seems to imply it would be "no problem" to raise draw height on the Stealth by one meter and increase spinnaker size. At what point would you be worried that the (current) mast would not be able to reliably handle this?
<br>Or is it that you intend to produce new masts (longer also?) designed to handle these (IMO) greatly increased loads?
<br>Seems we may already be facing a bit of an "arms war"??
<br>
<br>Kirt<br><br>Kirt Simmons
<br>Taipan #159, "A" cat US 48

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Kirt Simmons Taipan #159, "A" cat US 48
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Re: spinnaker draw height [Re: Kirt] #719
07/27/01 02:28 PM
07/27/01 02:28 PM
Joined: Jul 2001
Posts: 183
john p Offline
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I'll let you know on monday I just got a new 21 sq m spinnaker and it sets 300mm down from the top of the mast if it falls down Ill let you know, I dont think that the size of the spinnaker is important from a loading point of view, the platform will only take so much load from the top of the mast before it pitchpoles, the only difference with a bigger spinnaker is that this happens lower down the wind range. I am convinced that our mast will take this load, someone else allready tried it, but well just have to wait and see.<br><br>

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1103- (175 downloads)

John Pierce

[email]stealthmarine@btinternet.com
/email]
Re: spinnaker draw height [Re: Kirt] #720
07/27/01 07:33 PM
07/27/01 07:33 PM
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phill Offline

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Kirt,
<br>I am concerned about the draw height.
<br>Would you mind telling me what draw height you are currently using.
<br>
<br>Personally I'd like to see the max draw height set at 7500mm
<br>up the mast from its base.
<br>It will be very hard to start up a class that breaks $3500 masts. (Which is what a rigged carbon mast would cost, the blank is at least $2700)
<br>
<br>It would provide good amunition for the major manufacturers to run down the fragile (making it expensive) F16HP.
<br>
<br>While performance is a main focus without durability you won't get many participants.
<br>
<br>Regards,
<br>Phill<br><br>

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I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!

Re: Stealth weight [Re: john p] #721
07/28/01 11:43 AM
07/28/01 11:43 AM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline OP
Carpal Tunnel
Wouter  Offline OP
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>>We believe we can reach the 100 kgs weight for production stealths,
<br>
<br>This is great news ! I was a little bit anxious about the stealths weight. But this settles it I think. All the boats including genaker gear are between 100 kg's and 110kg's so I see no reason now to set a different minimum weight than 100 kg's. What do you think Geert ? Does this settle out discussion ?
<br>
<br>It was also assured to me that a homebuild Taipan could be build to 100 kg when modified here and there to take a carbon mast, carbon genaker pole and carbon beams. For a homebuilder all do-able. The carbon mast must be ordered ofcourse lets say that a blank carbo section = 2700 as phill indicated than going carbon will put 2700 - 1000 (alu) = 1700,- (NFL) = about us$700,- on the price of a boat. The sails etc will be different but just as cheap/expensive. So I think that is is payable too.
<br>
<br>
<br>>>We seam to be moving towards agreement on most topics, to summarise it would appear that the framework will be something like this:
<br>
<br>Yes, I think so too. Although I would like to run a few things passed you all.
<br>
<br>Max length 5.00 m (I agree)
<br>Max beam 2.5 m (F18 has 2,60 as max, more width more power in heavy air, do or don't?)
<br>Max mast length 9.00 (I agree)
<br>Min weight 100 kgs (Ohh yes, I agree)
<br>Max spin 17 m (18sq m???) (I like to move up to 83 % of 21 sq.mtr. = 17,5 rounded of, Do or Don't guys)
<br>Max draw height on kite ? 8.5 m ?? (I want to have same aspect ratio as F18, means less draw)
<br>
<br>Rated main area (as per Wouters calcs (I agree, ofcourse)
<br>Rated jib area (see above) (I agree again)
<br>
<br>
<br>>>>Boats to rate the same as F18 (I think we need to pick a rating system to compare its a bit too open to make it compare on all systems,
<br>
<br>
<br>I'm with you here, personally I like to opt for ISAF system. Name ISAF is better known in the world and allying ourself to this system will give us more credit and maybe help in getting support and recognition by ISAF in the future. I also think it is more fair to the F18's
<br>
<br>
<br>>>I vote we use texel this allows us 18sqm spin with no penalty over 17sq m it also allows any length of daggerboard
<br>
<br>I meet you halveway 17,5 sq.mtr. for I can argument mathem,atically that size is fair to the F18's. 18 sq.mtr. will look like we're trying to beat them by sneaky use of a loophole in a handicap system. Personally I'm all for more power and going faster but this is one thing again that could hamper the class.
<br>
<br>>>whereas for ISAF you must put in the length and area for the boards.
<br>
<br>True but these and all other non conformaties are corrected out in the jib area. So this is not really a big problem. with big boards you'll only loose 0,5 jib area or so 1/9 of max. that can be had on a F16HT.
<br>
<br>Wouter
<br>
<br>
<br>
<br>
<br><br><br>

Attached Files
1130- (171 downloads)

Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
I say go up too 17.5 sq.mtr. but not more/draw to. [Re: john p] #722
07/28/01 12:02 PM
07/28/01 12:02 PM
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Wouter Offline OP
Carpal Tunnel
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83 % rule (or 91% rule same thing) would allow a fair to F18's genaker of 91,075% * 91,075% * 21= 82,946 % * 21 = 17,42 sq. mtr. rounded of to 17.5 sq.mtr.
<br>
<br>I can sell this size using math arguments. I can't do the same for 18 sq.mtr. let alone 21 sq.mtr. I'm also a little bit scared of being accused of using rating system loophole in by the other classes. I don't mind what everybody does under Texel, (Hell, I might well go 21 sq.mtr. myself just to annoy them) but from a official standpoint it is a bad decision.
<br>
<br>Keeping same aspect ratio would make the our case more convincing too.
<br>
<br>max up mast of F18 is 8150 mm
<br>max hieght mastfoot is 120 mm
<br>
<br>so max hoist F18 = 8150+120 = 8270 mm not including place of pole on beam
<br>
<br>91 % rule would give a F16HP hoist of 7532 mm let say 7530 mm from top of forebeam.
<br>
<br>together with a pole of about 91 % of the F18 would give a genaker of 83 % size (17.5 sq.mtr. ) with the same aspect ratio but with a 91 % lufflength still giving the F16HP an advantage. Making the F16HP 100 % equal in every respect to the F18. Excluding topspeed for now for I'm still working o the math for that.
<br>
<br>I know this is difficult to agree upon when we all want maximum performance but lets not forget that we'll need to actract other sailors to this class and F18 equality for less costs with a great solo option might just do that. Going off in hunt for 1 or 2 % percent more performance might scare them off again. I would like to press everybody to think long and hard about this.
<br>
<br>
<br>Wouter<br><br>


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
You're talking AUS $ or US$ ??? [Re: phill] #723
07/28/01 12:07 PM
07/28/01 12:07 PM
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Wouter Offline OP
Carpal Tunnel
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Phill,
<br>
<br>I think we're on the same line here. I just would, like to replace your 7500 for the 83 % rules 7550 mm. I'm sure you won't object to that.
<br>
<br>BTW we forget another thing. Guys we'll aslo have to SOLO this genaker.
<br>
<br>Wouter
<br><br><br>

Attached Files
1133- (173 downloads)

Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Framework so far [Re: Wouter] #724
07/30/01 03:50 PM
07/30/01 03:50 PM
Joined: Jul 2001
Posts: 183
john p Offline
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john p  Offline
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Posts: 183
I can live with the smaller spinnaker, |I was not taking into account the one up sailing option, so I think unless we go for different size spinnakers between the two 17.5 sq m is ok, I agree with you on using ISAF I only went for Texel to get the bigger spinnaker in, I also agree with you on 2.6 m beam, funnily enough we were testing a 2.6 m wide platform yesterday and it worked fine.
<br>
<br>draw height set at 7.5 is lower than I'd really like but I'm not that fussed, incidently we used a 21 sq m spin at the weekend set 30cm below the top of the mast the boat was ballistic, unfortunately we ran aground at full speed (24.8 mph on a gps). The mast held up.
<br>
<br>We are very enthusiastic about this project and will produce a boat as soon as we all agree the rules
<br>
<br>Anyway the only thing I'd like to specify now is board length, board length and area is a part of the ISAf formula so to keep at 101 boards will have to be regulated or else people with longer thin boards will have to lose some sail, we have experimented with boards between 450mm and 750mm long, 250mm wide, I think 650 x 250 works well but some limit needs to be set to save recalculating sail area for individual boats, any comments.
<br>
<br><br><br>

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John Pierce

[email]stealthmarine@btinternet.com
/email]
Re: Framework so far [Re: john p] #725
07/30/01 06:01 PM
07/30/01 06:01 PM
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phill Offline

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John,
<br>In calculating the board length x width I assume this is just the area below the keel?
<br>
<br>Phill<br><br>

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1199- (176 downloads)

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!

Re: Framework so far [Re: john p] #726
07/30/01 06:09 PM
07/30/01 06:09 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline OP
Carpal Tunnel
Wouter  Offline OP
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North-West Europe
John,
<br>
<br>I'm very pleased with your commitment of actually producing a F16HP. This is really more than I hoped for when we started.
<br>
<br>But I need to beg for time, with the name change conversion , grammer checking of the homepage , structural analysis and advice on experimental setups and developing the performance model for equalisation and the give a definate answer on the outstanding topics like max width and max sailarea I really have no time left !!
<br>
<br>Good point on the boards but it has to wait a bit. It will be put on the to-do list.
<br>
<br>The comming two weeks I'll be consilidating what weve got now and prepare the choices we have on topics like genaker hoist etc. so we can all decide what is best after everybody having reviewed the same options.
<br>
<br>
<br>
<br>Wouter
<br>
<br><br><br>


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: Framework so far [Re: phill] #727
07/30/01 06:12 PM
07/30/01 06:12 PM
Joined: Jul 2001
Posts: 183
john p Offline
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john p  Offline
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Yes Phil<br><br>

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John Pierce

[email]stealthmarine@btinternet.com
/email]
Re: spinnaker draw height [Re: phill] #728
07/31/01 06:55 AM
07/31/01 06:55 AM
Joined: Jul 2001
Posts: 344
Arkansas, USA
Kirt Offline
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Kirt  Offline
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Joined: Jul 2001
Posts: 344
Arkansas, USA
Phill-
<br>That is the height I am currently using, which is the one recommended by the Taipan builders, AHPC and Goodall sails (and I suspect will be the height that will be "class legal" eventually?).
<br>
<br>Kirt<br><br>Kirt Simmons
<br>Taipan #159, "A" cat US 48

Attached Files
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Kirt Simmons Taipan #159, "A" cat US 48
Re: Framework so far [Re: john p] #729
07/31/01 09:51 AM
07/31/01 09:51 AM
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phill Offline

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John,
<br>
<br>Thanks.
<br>
<br>The Taipan class rulles require the boards to be between 290mm and 330mm from leading to trailing edge when they leave the case. And mine are 290mm.
<br>I'll check to see how far the boards go down below the keel.
<br>
<br><br><br>

Attached Files
1234- (205 downloads)

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!

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