self rasing daggerboards

You wont be able to use a rope to raise them.

Actually this year I saw just such a sysem introduced to the EU Blade F16's. It was first tried on some A-cats I believe. It seems to work well.

The tape is however glued to the boards somewhere in the middle of the cord and not the leading egde.

I didn't ask about the exact type of type material used. It was woven but felt smooth nevertheless.

I don't think a pully or block was even used. The tape just rested on the hull and that was it. But I'll have to check. Won't be able to do that till sailing season starts here in EU, april 2007.

Wouter

Yes, no pully needed. Cord style lifters just have a fairlead at edge of casing.
I have a Nacra 14squred which is new to me and after my PT I am clear that these boards desperately need lifters.
The attachment needs to be in middle of board and lift at right angles to deck. Don't be tempted to try to follow cant of boards.

hey there Bandit,
Was on Stephens F18 which has a 1cm thick piece of material about half way down and he doesnt use a puly system or anything like that it just sits there.
Alot easier to pull the boards up with this type of system rather than the manual lifting system.
The system on his boat must be alright considering its a capricorn
Cheers
Will

The ribbon like material sounds like it could work. It attaches to a rope as it finishes its journey across the tramp.
That sounds like what I am after but the next step is how to pack the top and bottom of the casing so the board can move freely up and down but with as little sideways play as possible. It would have 160mm of ribbon exiting the hull so mounted on the sides it might catch the water flow. On the leading edge it would flow nicley to each side. A roller made from a pully mounted at bottom of the caseing pushing against the leading edge would help hold the ribbon in place. Still I am keen to hear more veiws on the subject as I am still turning the cogs in my brain for the best solution.

Stephen just has some type of carpet like material to slide alond and it seens to work really well. Had no trouble bringing the boards up. Seriously thinking about trying on the mossie.

Can you make it so that when one is down the others up?
Connected so all you have to do is push one down when you tack?

A little bit of engineering and testing Im sure you'll be able to do something of the sort. Make single handed sailing alot easier.

William

Hey Will,

Looks like a few of the boys will hit out again this Sunday for some more training.

Thats the idea I was looking for.
Next question what is the strip made of.
I was thinking a rubber strip that goes directly across to the other board applying stretch when the boards are down.
You could then release the rope that pulls the boards down and thay could pop up automatically.

The line is webbing such as used for seat belts.

Our cats are designed to utilise both boards when going upwind and need pretty much the full area of both. Try sailing with only 1 board and note results.

We shattered a c/board in the first race of our states (first lap) and raced the remaining regatta with only 1 board.

No Port tack without starboard board..... We slid sideways a LOT. If we flew the hull too high, we lost a lot of ground. On the other tack we made better headway but still slid sideways a bit compared to boats around us.

Thanks for the info I like my rubber idea but I am not sure how well it will work so I'll give it a go and if it doesn't work I will end up using the webbing. The next big problem is a strong bonding from the strip to the board.
Any recomendations out there?

The Cap has a hole drilled threw the board and the webbing is epoxied in.

Thanks for that Steve I have a clearer picture of what I want to do. I'll use the webbing as it will absorb resin better than rubber. To save my auto raising idea I might run the webbing under the tramp and connect it to a strong bungee to pull them up. This will rely heavilly on the how freely the boards lift up.

When the boards are loaded up, they can take some effort to raise. More than what I believe you will be able to achieve with bungee...... But by all means, give it a shot or try other systems.

has anyone ever thought of making the boards bouyant so that they pop up naturally? Then all that would be needed is a line (there ya go Robi) that would run from either side of the trunk, through the top of the board. When you pull the line, the boards go down. Cleat and it stays down. Uncleat and they pop most of the way up themselves.

Standard feature on homebuild Taipans. Sadly they do also pop up during tacks and such. That is why quickly all kinds of friction devices are fitted to keep the boards down.

Wouter

would something like this not work?

Tad that wont work its not an f16. LOL

Your diagram is how I plan to pull them down but unfortionatly you cant make a board floaty enough to self raise completely as they are already foam filled but to keep them strong the fiberglass makes them to heavy.
Put a board in the water by itself and it floats happily.
Lift one end of the board so its now vertical and half the board dissapears under water to remain afloat so I definatly need a good rasing system to fully retract the board. I need a good frictionless packing for inside the casing to stop the board from jamming. A 3 point roller system might work but it gets too fiddley and I think it would need a complicated mounting to align the rollers. So Id like to follow the K.I.S.S rule. I need the best frictionless carpet or padding. I will buy a few samples and experiment wet and dry.

I tried using bungee to raise the boards but its the distance they need to travel thats the problem. To completly raise them they need 60cm of travel which equates to aproamatley 3 meters of 10mm thick bungee per board and they will be loaded with too much tension making them very hard to lower. I have noticed the boards sit directly under the side stay which could save adding the strap under the water line. I could run a pully 200mm up the stay. Has anybody done this or used the stay in this way? pros and cons?

I am tring to keep the tramp clear of ropes so I need the rope for the lowering of the boards to run up the hull and along the front beam and onto the other board. The same setup as used for the 2:1 rudder system.
I am considering running the rope over the top of the board through a mounted roller on top of the ceterboard at a 20 deg angle compared to the usual 90 deg in relation to the board direction, so as to keep the rope running up the length of the hull.
This idea would require less pulleys to direct the rope around the tramp instead normal version which goes stright over it.

Any other suggestions or forseable problems with this idea?
Can you share the wisdom of your setup and why you think its good or bad?

Boyer used a rope system on their A cats and Taipans for quite some time. Sailed some of these boats too. The 4.9 also has the rope system. My personal experience is shared by many who also got rid of any ropes nowadays. The fear for jamming the rope between the board and the case is not worth the benefit of the system. In theory it sounds nice to go on a flyer and just pull the rope for the leeward daggerboard to lift it, but than again, you can do the same a few meters further down the track without any of these ropes too. I think nowadays very few A still use a rope system. Just didn't pay off. And once you really jammed a board you surely want to get rid of all those lines. Just imagine approaching the beach and you don't get your board up. Ends up expensive.

I nowadays glue some webbing to the case in the upper and lower part to increase enough friction the board stays up when lifted (and stays there in a capsize) and thats it. No lines, no extra weight and a clean tramp!

The 4.9 system is an old one which I have had on the 4.9, a paper Tiger and a Tiger Shark. These all worked very well and the only reason they jam is not using them properly. Jams are usually fixed by simply pulling harder. THis system is great and I am investigating doing to my 14 squared. I may us a flat web but the theory is the same.
Rope system can work very well for up and down in concert with a bungy to create tension.

I shouldn't have jamming problems I am using 3mm x .5mm polyester strap that is very small and slippery in texture.
I have tried this rope out and it works seamlessly even under large amounts of strain. But its still early days so...

Finished the line setup for the ceterboards and this is my final layout after much testing and it works very well.
see attached.