Incase anyone isn't up to speed on the above abbreviations
LCB = longitudinal center of bouyancy
LCF = longitudinal center of flotation
Cb = block coefficient
Cm = midships coefficient
Cv = volume coefficient
Cp = prismatic coefficient
Cwp = waterplane coefficient
Cheers
RG
Just occurred to me that perhaps some others may not have some hydrostatics software, if so, just yell and I'll do what I can to help you out with getting some numbers for your hull. An igs file of your shape will generally get me started easily.
Cheers
RG
Hi Scarecrow
I actually really like the look of that, without me trying to study between the two, what changes have you made in regards to Mk1 to Mk2.
I'm all for centreboards and stayed rigs, I didn't have any trouble throwing up an stayed rigged aluminium rig when we were kids.
Are the plans available for this one? Also include a set of plans for a bigger shed, I think I'm gonna need it <img src=
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Regards
Makes sense, although a Mossie is an F16, right? If F12 is successful as a younger kids boat, maybe it could be the springboard Darryl and Bernie need for the F14, and from there people go to F16/F18/A depending on their preference and to a lesser extent on adult body weight.
Thanks RG, now the things starts to look more serious...
mk II
LCB 46.6%
LCF 42.4%
Cb 0.475
Cm 0.885
Cp 0.639
Cwp 0.721
For those who are a little new to this. Traditional theory is that keeping the LCF and LCB as close as possible will minimise pitching and keeping the LCF as far aft as possible will help prevent nose diving.
A high Cp is traditionally considered quick and a low one is considered easy to turn.
Matt Plans and kit are coming on line over the next couple of weeks (see pricing thread) the price will be slightly lower for the kit as I've eliminated one sheet of ply.
changes between two versions are a basic tidy up (first one was done very quickly) and a reduction in freeboard and some tweeks to the internal structure.
Chris.
I am avere that I might mess the things upp by this, but would it not be a good idea to go for a cat with a little bit more wolume like RG and for the rig to make it like Scarecrow. This would make the boat for a larger range of kids. Say small kids 2 up and older kids 1 up. That would make the platforme last a little bit longer, and also make it more adapted for raids.
Gato....already working on that <img src=
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Cheers
RG
One thing we should all be thinking about, and Wouter brought it up to me in an email because it hurts the F16 class, is a revenue stream so that those running the class have some funds to help promote and develop ideas/racing etc.
Wouter wanted to do this with common production of stuff like masts, braces, booms and sails etc with a small portion going to the class. While this is a great idea, its sorta goes back to limiting what all of us who are designing various stuff believe in.
My suggestion is that all of us designing each of these designs, add a small fee ($50 ?) that goes directly to the class treasury so they have some funds to pay for things like Scarecrow and I are currently helping to fund because we can. This also implies that we had better get our act together and elect some people to run stuff in short order, finish the class rule and generally look a whole lot more like a class than a bunch of people who are in love with a concept.
Later, as the design and experience spiral narrows and we end up with more designs that incorporate more similar features, perhaps we can utilise some of Wouters idea's also.....or if any of you have other bright idea's for adding other possible revenue streams for the class, please speak up.
If you look at the F16 forum right now, they are having a discussion on how best to promote themselves further, but as a class lack the funds to do it in a major way....one of our primary goals as a class from the start should be to give those who run it, the tools (read $) to help get it started on the right foot.
Even small $ could get us the equivalent of the BIC video that we could saturate the web with and get the parents with the $ aware of what we are trying to do.
Cheers
RG
Sounds good to me, a small
licens
fee paid when you buy the plans makes it equal for everyone.
Gentlemen,
If the F12 Class Association is formally organized and this fine volunteer work converge to a one design class, I will buy plans to build at least one boat for my kids here and will also donate USD 500,00 to help with the class startup.
Afterwards, I will try to interest builders and start advertising/
marketing
the class in Brazil, Argentina, Uruguay and Paraguay (and all Latin America, if possible) as:
1) A great double handed startup boat for a couple of kids (one F12 for two siblings is cheaper, safer and easier to rig than two Optimists);
2) The ideal singlehanded upgrade for kids bored with the Optimist;
3) Part of a worldwide youth effort to support multihulls and high performance sailing in general, in response to ISAF's controversial choice of Olympic equipment.
We should try to coordinate similar actions in all Europe, North America, Australia, New Zealand, (South) Africa and (hopefully) Asia.
Keep it going,
RG,
great idea but the devil will be in the detail. We need to find a way to administer the class (and budget) internationally. The other thing to consider (assuming we get ourselves organised) would be to try and find a couple of association sponsors / benefactors.
Just a fundraising thought guys, what about when you pay your licence fee you get a hull number and F12 stickers to be attatched to the hulls (thereby adding value to your licence fee). On these stickers could be current sponsors name who would hopefully pay for the sticker and sponsorship of the class including a profile on the web page.
I told my daughter I am organising to build a catamaran for her and she looked really sad. I asked whats wrong and she said she wants a small A class. <img src=
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I told my daughter I am organising to build a catamaran for her and she looked really sad. I asked whats wrong and she said she wants a small A class. <img src=
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/> <img src=
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Good fundraising idea.
I have a 12 y.o. daughter who used to sail cats with me. She got bored in an Optimist after 5 times out, but couldn't handle a standard Laser and liked her only day out in an Europe.
I told her that we will build a cat designed for her age, size and weight, faster than any boat a parent would allow someone her age to sail - including the Laser and Europe. She loved the whole thing.
Maybe just copy the F16 class organization?
The first (and essential) prospect sponsors, benefactos AND BENEFICIARIES are the main cat manufacturers in each country. If they are minimally inteligent, they will understand the need to support an international entry level cat to train people to consume their products. Especially when they are free to build and sale the F12 too.
Luiz,
I think that before we hit the manufacturer's we should first demonstrate that we have a viable class, or they are likely to look at us as a lost cause before it starts
Cheers
RG
Final Hull, this is a compromise shape between speed and being easy to handle and the result of a whole heap of VPP runs....while it looks similar to the previous stuff, the transom is wider, rocker is changed slightly and is both wider and narrower in places (just a few mm here and there).
The really good news is that I now think I'll have (not a promise, just an optimistic guess right now) about 5 boats building by Christmas so about February/March we should have some on the water pic's and performance reports. Wish I could do it faster, but I think this is a realistic time frame. Will post pics of the builds as they evolve. As I was changing the hull up until yesterday, cutaway pics are still a week or so away.
Enjoy the new pic's
Cheers
RG
Latest Hull #2
Latest Hull #3
Latest Hull #4
Latest Hull #5
Latest Hull #6
Forgot to mention that I have 2 people interested in the round bilge version also, If Im lucky, the first of those might start building in Jan-Feb 08
Cheers
RG
RG, do you anticipate that the round bilge version will have different performance characteristics? How do you see the relationship between the two playing out in the market?
Mark.
Mark,
not sure how they will play out in the market, but I can tell you that the price point/work required to build difference makes the round bilge one maybe 3 times harder to sell...is for that reason why I did 2 designs....at the very least, the hard chine one will see at least a few more built 🙂
As for performance, none sailing yet but my VPP (which often lies to me ) says that the performance gain for the round bilge one is about 5-6% uphill and about 8% downhill, but you have to remember that its basically a scaled down A-boat and hence a lot more slippery.
Cheers
RG
this note comes under the heading of miscellanous thoughts....
In the course of trying to get a few people interested in building these boats Ive now had 7
moms
say, hey, I'd like one so I could race with my son's/daughter's and the available other cats are too large for me. (ever noticed the large number of mom's on the beach while the kids are out sailing?)
Where we run into a problem is weight wise (this has already been discussed a lot) but one easy thing we seem to have overlooked is what they do with the F-16's which is to add sail area to equal out the weight penalty.
After thinking this thru a bit, I don't see any down side to having a version for adults that has a bit more sail scaled to some weight formula, especially if those adults want to be able to race with their kids....in fact I think its a real plus as far as encouraging kids more.....what kid doesn't want to be able to beat mom or dad on a more or less even basis? <img src=
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Chances are that they won't cause mom/dad are better sailors, but I bet it will make them try a whole lot harder.
Just my ramblings for this evening
Cheers
RG
PS...this in no way means I want to change the rules as we understand them now....just add a bit of latitude to them to accomodate a broader range of participants based on feed back Ive had...the basic rule for the kids should stand as it is!!!!
JeffS, you've got PM. Well I think you have anyway.
Sure why not? The laser has 3 sail sizes and two mast lengths. The lower section of the mast is shorter for the 4.9 and the Radial (5.7) then the laser (7.0). <img src=
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It is also a different mast section totally unlike the standard version except for the outer diameter.
Remember guys the rig is most costly part of the whole design. It will be better to use the same mast section and just fit a larger sail to it for adults (with less luff or leech curve)
Wouter
Absolutely. The sequence is:
1 - Preliminary: class rules / design
2 - Startup: class association / first boats
3 - Expansion: start marketing / races