Dagger board jamming

[Jack Sparrow]

When running on a beam reach we pull the dagger board up to limit drag after rounding the bottom mark we the lower the board to beat up wind, becuase of the fwd motion loading the board against the rear face of the dagger board trunk the foil will not drop all the way down, thus increasing side slip when beating lowering preformance. My fix is to pour some lead into to bottom of the foil not a lot about 5 kgs so I won't have to beef up any of the lifting gear. Has anybody come across this before and what was your fix.

Jack Sparrow

[Boblee]

Could you drop the board before you round?
Wouldn't think 5 KG would make much difference but for sure someone would have had the problem, just tie mine off approx where I reckon and leave it, it drops down soon enough but am not worried about it normally.

[March]

On a 26X, the board goes down eaily when there are no lateral forces involved. As soon as the boat is pushed sideways, the board is jammed in its casing and you might have problems getting it all the way down. You may also feel like it's harder to retract it. That makes a lot of sense. You want a stiff daggerboard, not one that goes easily up and down on its own.
Adding lead to the board: I am not sure whether the board is empty on the inside (the original rudders on the 26X seem to have some empty spaces inside; there is a significant amount of water coming out of mione when I pull them out of the water) If the board is massive, then you will have to drill a groove, add the lead, only to find out that 10 pounds of lead will not make all that much of a difference when it comes to the lateral forces that jam the board.
Maybe adding a lead bulb would work better, but that would require some additional engineering in case of a swinging keel, so that the board can still retract all the way in, when it comes to trailering. There might be a mod in that respect on the board.

[tangentair]

There was a thread about this http://macgregorsailors.com/phpBB/viewt ... gger+board that you might want to read through. They used a lot more than 10 lbs / 5 kilos.

[Boblee]

The board is hollow and it has holes drilled to allow water in but this will take time, not being that interested in racing etc it hasn't been a concern as by setting the line and leaving it is only a short while and it has dropped while you are doing other more important things.
But if you need the speed of getting it dropping faster? by adding lead you will probably help stability a wee bit but personally anything that adds weight gets serious consideration.

[tangentair]

...but personally anything that adds weight gets serious consideration.

That is my concern also, due to the side forces involved, the board if reenforced with lots of lead could cause stress cracking at the exit area, or if the lead is lower than the exit point could cause cracking of the board. Still, 220+ kilos or about 500 lbs would certainly have a righting effect and dampen that roll in gusty winds.

[pokerrick1]

and what was your fix?

Heroin Remember - - - I am in Hollywood

Rick

[c130king]

A bigger issue in my opinion is raising the dagger board when on a beam reach. The side pressure makes it difficult to raise sometimes.

I turn in to the wind for a second, pull it up some (for instance when approaching shallow water), and then turn back to beam before I lose much headway.

I am hoping a 2:1 system, like I have on my rudders, will make pulling it up a little easier.

I Don't worry too much about dropping it, it will eventually slide all the way down.

But I do wonder how much weight would be needed to make a noticeable difference in stability? Leon has put weight in his dagger board...but he is probably a little more in maximizing performance than I am...

Jim

[puggsy]

THE IDEA OF A MOULDED, WEIGHTED BULB IS A GOOD ONE...but would require an alteration in the construction mould at the factory...virtually an indentation to accept the bulb. This wopuld take up some space in the ballast tank but not really affect asny other setup...Maybe Roger will give it some thought. puggsy 06

[NiceAft]

Jack,

I understand why raising the board is effective while running, but on a beam reach? There are still lateral forces involved creating slippage.

I believe Leon has a weighted board. You may wish to either do a search of his posts, or a general search of posts for the subject matter.


Ray

[NiceAft]

Jack,

I understand why raising the board is effective while running, but on a beam reach? There are still lateral forces involved creating slippage.


I believe Leon has a weighted board. You may wish to either do a search of his posts, or a general search of posts for the subject matter.


Ray

[parrothead]

I have also found that the daggerboard on our will not drop fully if the boat is making any sort of significant headway. My solution is to extend a boathook and push down on the board through the open top of the trunk. It's a simple and direct fix.

[Jack Sparrow]

Sorry Ray running and broad reaching is what I sould have said. I am also thinking about Teflon painting the aft dagger board edge to aid in slippage, I managed yesterday to fill the lower vent holes with lead today I plan on glassing over them to make them water tight this will allow me to drop the bottom edge in water to stop distortion when the lead is poured in

Jack Sparrow

[bscott]

I used a 1"forstner drill bit, a series of 4 holes/side and over filled them with buck shot/epoxy mixed. When curred, sanded smooth and painted over them with epoxy, then final bottom paint. 30# seems to be OK. BTW, epoxy is heavy stuff.

Its easy and safer to work with and you can always drill more holes later to add more wight.

Bob

[Frank C]

A bigger issue in my opinion is raising the dagger board when on a beam reach. The side pressure makes it difficult to raise sometimes.

I turn in to the wind for a second, pull it up some (for instance when approaching shallow water), and then turn back to beam before I lose much headway.

I am hoping a 2:1 system, like I have on my rudders, will make pulling it up a little easier.... Jim

Jim,
The design intention of Roger's board-to-trunk clearance is to spread the lateral resistance forces across a fairly large area, but you're talking forces in the hundreds of pounds, plus lots of friction. Luffing the sails is the common technique for adjusting depth of both the C-bd. and the D-bd.

Just guessing here ... a 2:1 tackle wd be inadequate to significantly change your lifting ability while lateral resistance is in-play. Fact is, if you add enough purchase to lift it, you'll prolly break one of:

• the lifting area at top of the board;
  or the lift-line;
  or the turning blocks;
  or ???

Not sure if Bob (bscott above) is endorsing the idea, but at least two other Members have added weight low in the D-bd. But I haven't seen either of them recommending it very heartily. Leon (delevi) & Erik Hardtle are the other guys to ask.