You are absolutly right, and with the DS12 on the cartop i think that your picture would be complete

Hi all,

I have been following the progress of the development of the F12 class since I first saw an article in Multihull World in Aus last year. Firstly, congratulations to all of you across the world who are contributing to this new class. I can imagine how difficult it is to float a new class, get momentum behind it and eventually critical mass.

I have sailed various classes over the last 25 plus years including Arafura Cadet, Mosquitos, Taipans, F16's etc, and I can see a real place for an entry level junior cat class.

I have no desire to buy into the debate that has developed over the design/class, and if I thought my comments here would be taken as negative, then I would not post, as I have nothing but respect for all of you as you undertake this journey.

However, with 3 sons, and a potential customer/builder of a number of F12's in coming years, I do have some comments on the design concept.

I agree there is a need for a contempory, entry level cat, which will replace boats such as the Arafura cadet (which I loved as a kid, but that is progress). I believe it needs to be kept simple, efficient, robust, safe and cost effective.

I can't help but feel that the current rules are too broad and allow too much development scope, which may see the class stray away from the objectives as set out in the first few lines of the draft class rules. Imagine what I consider the worst case:- designers, builders and buyers with deep pockets developing all carbon boats, including platforms, masts, beams, rudder stocks, boards, booms etc. I am guessing a boat like this would be somewhere over $10K. Certainly not cost effective in my book for an entry level class, in the hands of 8+ year olds.

I imagine a simple model, that allows flexibility in hull design/construction methods, ie. ply, foam sandwich, etc. however with restrictions on rig design, beam design and material, rudder stock materials, etc. Do we really see this entry level class being a development class similar to the A Class? If so, fine, but I imagine this may reduce the possible purchaser/builder population, and may disengage the teens who are sailing these things and get pissed off when someone comes along with something newer/better/etc.

I have never lost a single $ on buying/selling boats (obviously except for maintenance/running rigging, etc)cos I have always sailed boats like mozzies, taipans, etc that I knew would hold their value year on year assuming kept in good condition.

Anyway, just my thoughts. I will continue to review all of your progress with interest and wish you all the very best for your future efforts to get the class a vibrant addition to any club and regatta.

Regards,

Ross

A very considered and thoughtful post Ross.

I couldn't agree more - the key must be a design that is cost effective.

I am really keen to get my kids involved in sailing cats, but cost will definitely be a factor for me.

I too am following the progress of the F12 - I am really excited by the concept and am likely to be a customer/builder too.

Matthew

After building the DS12 (ply) and the Tabby (foam/glass) and both came out just about the min. weight for a cost of about 1500 USD all included I think that the risk is not very big of somebody wasting a lot of money in carbon, still you would not need much so It would not add so much to the total cost.
The far bigger risk is that somebody is coming up with a design a “lot faster”, but isn’t that what the formula class is about?
These cats where from the beginning intended to be homebuilt. A handy dad can always build a cat with his kids that will be faster than those you can buy readymade, still the price will not be higher.
Still even that is not in my opinion likely to happen. I think we will end up with 1-3 designs rotomoulded production low cost cats on the market.
If some day there is somebody thinking it worth spending 10.000 in a F12 it will just be a proof that the class has been a success and by then there will be thousands of F12 cats on the beaches around the world.

G'day Ross,

I concur with your sentiments however I'm not sure the F12 "knows" what it is yet; kids trainer, kids racer, teen racer, adult racer/cruiser. What we do know is that there is a fair bit of interest in the class from a lot of different ppl.

For now, it is open to every one of the above groups and my opinion is that whoever likes it the most will eventually steer it towards the F12 concept, it will evolve. Over time, material issues will be resolved, but I don't believe there should be too many restrictions here; for such a small boat, material costs are far outweighed by labour.

We've also seen, over a long period of time now, that apparently conservative restrictions in materials and suppliers do little to lower the costs to the boater; eg. AUD$1100 for a laser sail is ridiculous. I would like to see competition amongst suppliers leading to lower minimum costs.

My personal vision of the F12 is as a kids trainer & racer; no adults, 2 age divisions, 1-up and 2-up depending on division. I also see a benefit to a one design, but not SMOD, rig and sail plan similar to the very successful IOM class. For a home build, the rig will be a very significant cost and complexity and one designing it will help. Not sure about one design beams yet, but from a practical point of view only, they would also be a benefit. To tell you the truth though, a set of home-built carbon beams would cost very little if done correctly. And consider longevity issues of aluminium parts vs carbon. The evidence just isn't there to argue against carbon for some parts when considering long term costs; eg. there are 10 year old carbon masts winning races in the 12' skiff class.

There is also the issue of complexity of the rules, which has been discussed previously, and I don't think it is time for the F12 to develop a set of rules as complex as say the optimist just yet. Again it is a part of the evolution of the class.

Hi gents,

I much appreciate your comments and feedback. It's interesting to see how this class in developing and how much interest it is receiving from around the world.

To your point ncik, I agree, it appears unclear what this class is yet. There is clearly a HUGE amount of cat sailing, design and building experience involved in the development of the class, and seems to me that there may be some positive benefits in having this collective experience draw up some design and construction guidelines that steer the class in a specific direction. Ncik, I tend to agree with your vision for the class, not totally restricting design, but restricting some elements that may/may not give some designs significant advantage.

Not for a moment am I suggesting the banning of carbon. It's strength and life span over aluminium are well documented, however to your point Gato, it seems to me that you may want to prevent a platform/rig design coming along that is significantly better than the others. This in effect would render existing boats all but redundant and people would have wasted their $1500 plus, and all the hours invested. A question for those out there...... how many 5 plus year old A class cats are competitive these days? There has been quite a bit of talk about the Arafura Cadet on this thread. I had one and loved it as a kid. But I imagine there would be none of these around today to even talk about if they had been part of a development class that rendered this 30 plus year old design redundant a few years after building. I remember when the AC went from solid bridge deck to aluminium beams and tramp. Even that was enough to cause debate in an already great class.

So the seed of thought is growing in my mind, if the Formula class does mean unrestricted development, is this the right platform from which to be developing an entry level training boat? Once again food for thought.

Regardless, I and my l
kids will still be looking to get involved in this developing class when the time is right.

All power to you guys.

Ross

Ross,

with respect to the use of carbon. Gato choose to build the masts for his two F12s out of carbon as a cost cutting measure, as it was cheaper for him to build composite masts than so source a suitable aluminium extrusion in his location. Limiting his boats to aluminium masts would have increased the cost of each boat by a few hundred dollars.

Hi Scarecrow,

Interesting and good to know. Would that also be the case for a pocket sleave luff system over a round section extrusion? This is definitely a concept I was impressed with when I was originally reading about the F12 Vudu. Looks modern, simple, light (I assume) and I guess is cost effective and fast I guess, as seen on moths, sail boards, etc. Is it considered a cheap option? How would you lower the sail while on the water?

Regards,

Ross

I may be wrong, but I have the feeling that at least the first Vudu:s have "normal" rig and sail.

IIRC, RG reported to me the other day that they couldn't find any sail makers willing to make the pocket luff, full battern sails.

Btw, any more news of the Vudu:s if I understood it right they are sailing. It would be nice with some pics.

Ross,

Alu mast with pocket sleeve sail is very popular in landyachting and an estimate for the costs can be derived from type of sailing.

Unstayed alu mast 5.5 mtr tall and collapsable in three pieces total cost 128.01 Euro.

Fully battened square top pocket luffed sail of 6.0 sq. mtr and pentex cost 417,22 Euro.

Shipping from France to Netherlands using DHL was 140 Euro's I beleive.

As Ncik says, round carbon tubes are relatively simple to make by a homebuilder. There is no reason why such a homebuilder couldn't make an unstayed mast from carbon this way. This setup also avoids lots of special hardware like hound fittings, halyard systems and spreaders. This saves costs and "simple = best" for a concept like F12 in my opinion. It must be the better looking and more performant laser dinghy version to the catamaran scene. Very simple, quick and easy to rig but inexpensive and performant. Making a 12 foot version of the A-cat, Tornado/F18 or Moth is not smart in my personal opinion.




You wouldn't. Just let it weathervane. The fact that it is fully battened prevents it from flapping about violantly. The lack of stays allows full 360 weathervaning. Actually, the is no limit to the amount of rotation a weathervaning sail can make. Added advantage is that a dummy can gybe the boat on land without mishap !

Both mast and sail for a unstayed pocket luff sail are really easy to make by homebuilding.

Wouter

Right, scores of dinghy and landyacht classes use these and "we" can't find a sailmaker willing to do us one ?

Where do the BIC dinghies get theirs ? The class 5 and promo landyachts ?



Bloody hell !

I'll give you a leg up.

I can get you a ready-to-sail unstayed pocket sleeved rig as displayed in the picture suitable for a heavy adult for :

Complete mast (collapsable 5.70 mtr tall from alu tube) 248.66 Euro
6.60 sq. mtr modern sail , transparant pocket luff 458,36 Euro

The reefable version of that sail is sligtly more expensive at 489,13 Euro

You only need to add the boom and the rig is ready to go.

Note how this unstayed rig the heaviest available and it is used for doublehanded landyachts using 7:1 mainsheet system fitted to the middle of the boom (combined downhaul and leech tension system). Its flexibility is optimized for about 250 kgM static righting moment. Comparable to a 75 kg adult hicking of the luff hull of a F12. A typical 12 year old child of 40 kg would use the lighter mast as I quoted in my other post (128.01 Euro).

These quotes are excluding shipping but the tallest section is only 2.70 mtr long and so international shipping shouldn't be too much.

The main point being that you can't get beyond 707.02 Euro excl. taxes and shipping for the strongest modern shaped off-the-shelve pocket luff rig (mast + sail) that is ready to be fitted and used. I seriously doubt whether it would go past 1000 Euro's incl. NON-EU taxes and shipping.

It looks like this. Note that the pronounced back rake of the mast is largely the result of the mast foot being raked back by some 15 degrees on landyachts. This is done to bring the sail pressure in line with the rear wheel axles. On a boat the mast could be raked straight up and only the mast bend would move the tip back by something like a mtr under maximal sheet load. The resulting boom clearence can be kept or used to some 0.4 sq. mtr. addition cloth as allowed under provisional F12 rules. I'm convinced that I can get a custom sail ordered from these guys for a reasonable additional fee. Afterall, they also do complete custom landyacht designs.

Note that I have a slightly smaller version of this series of rig in my possesions. I got the 5.5 sq. mtr. reefable version with the 128.01 Euro mast. It is the best rig I have for my class 5 landyacht. It pumps very well in the gusts and it is a dream to sail. This is quality stuff. For F12 usage they may be optimized here and there but the off-shelve-rigs will be a very good and cheap starting point for a prototype neverteless. They'll be quite close to what you want.

Wouter

Thank's for the input Ross, I like carbon I don't think it will cost much more initially but will save money over time because I can homebuild the components and repair the breakages easily. Carbon on and in the hulls will add that extra bit of strength for boats that will be lent out at club level to kids. It's great to see people designing new cats and showing their designs enabling me to build a cat that suits my area's sailing, my kids want jib and trap for crew and extra fun so why not give it.
I pick up my kit tomorrow so now I just have to find the time to build it before the Sauna Sail.
regards

Wouter,

Do you know what the diameter and wall thickness of the tubes are that go to make up those two masts?

Gareth

Hi all,

Very much appreciate your comments and replys to my questions. I'm learning more every time I log on.

The unstayed, self supporting rig does appear to be a neat way to go.

JeffS, you are talking about a kit you are about to pick up. I admit I have not read every F12 thread, so I guess I have missed something, but who is supplying the kits, what is included, and based on what design? Is it the Vudu? Also, is the kit available for purchase, and if so, who do I contact?

I currently live in Indonesia, and while there is certainly very little off the beach sailing here, I have a big guarage and may as well be spending my spare time building one of these, particularly something that can easily break down and transport as part of our consignment where ever we end up next.

Sorry to ask stupid questions, it's purely healthy interest.

Regards,

Ross

Well, I ended up at about 730€ all included ready to sail for my homemade rig.

Ross, where are you? I delivered Jeff's DS12 kit today.

Optional kit components are:
Precut gaboon plywood (skins, frames girder etc)
Pre-made aluminium rudder stocks
Premade front beam (cut, drilled, dolphin striker fitted, anodised)
Pre-made back beam (cut, drilled, anodised).

Currently working on mast, sail and tramp options.

you guys are making me so jealous, I would love to try my hand at building an f12 but at 1 and 3 i don't think my boys are quite ready just yet. They think they are.

Can't wait to see yours on the water Jeff.

Hi Scarecrow,

I am in Jakarta. Can you send me full details, ie. cost, full consignment size/weight.

I can't get anything here, ie. no sails, mast, fibergass or resins, so I would need to look at a kit with all components required to build. (I can get basic tools, and timber to make gigs, etc.) Maybe this is a bit of a dream at the moment, but please keep me posted as you pull together full kits.

Thanks