Replacement of Centreboard Downhaul

including Amas (Floats), Akas (Beams) , Swing Wing system and all other hull related issues.
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penryj
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Replacement of Centreboard Downhaul

Post by penryj »

Downhaul line snapped at the point where it enters the hole on the rear of the board. Is the only way to replace this to crane the boat and drop the board out throughout bottom?
Penry

DF35-25
Gwas Y Neidr
Steve B.
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I don't know about yours, but

Post by Steve B. »

On a DF1000, you take off the table top to access the board lines.
EarthBM
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Post by EarthBM »

I wanted to replace the downhaul line (mine's slipping through the jam cleat). Took off the table top and looked at it. It looks like the line enters the hole through the board edge, and then it must exit on the side so that a knot is made that prevents it from coming out of the hole it entered. This suggests that to replace the line this sideway hole needs to be exposed. I didn't see any way to do this other than removing the daggerboard. Which of course would be a major pita.

The upper edge of my board is about 5-10 inches under water at all times. I am betting that if I unload the boat and fold the amas it will lift above water. Not yet sure how it helps though. If there a way to undo the pivot axis and lift the board out of the water using brute strength?

I know people here have replaced those lines -- what did you do?
Ivan -- DF 35 #29 "Lykke"
EarthBM
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Post by EarthBM »

This thread suggests that what I describe might be a DF 35 specific way to attach the downhaul to the daggerboard: http://www.dragonfly-trimarans.org/phpB ... .php?t=280

For what it’s worth it looks like DF 35 uses the uphaul line knot stopper to prevent the daggerboard from slamming against the trunk.
Ivan -- DF 35 #29 "Lykke"
gminkovsky
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Post by gminkovsky »

@EarthBM

read my post on fixing board downhaul line: http://www.dragonfly-trimarans.org/phpB ... .php?t=250.

Much easier and cheaper than replacing the line.
EarthBM
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Post by EarthBM »

yep, this is what I may end up doing, but the thread was started by the poster whose line snapped, so the issue remains for him.
Ivan -- DF 35 #29 "Lykke"
Double Horizon
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Post by Double Horizon »

EarthBM wrote:I wanted to replace the downhaul line (mine's slipping through the jam cleat). Took off the table top and looked at it. It looks like the line enters the hole through the board edge, and then it must exit on the side so that a knot is made that prevents it from coming out of the hole it entered. This suggests that to replace the line this sideway hole needs to be exposed. I didn't see any way to do this other than removing the daggerboard. Which of course would be a major pita.

The upper edge of my board is about 5-10 inches under water at all times. I am betting that if I unload the boat and fold the amas it will lift above water. Not yet sure how it helps though. If there a way to undo the pivot axis and lift the board out of the water using brute strength?

I know people here have replaced those lines -- what did you do?
It would help if someone posted a picture of the 35 rope attachment details inside the CD trunk. From what you describe about the knot, is it possible to push the downhaul rope into the hole further while you pry the knot out the side with a long flat blade? (screwdriver or knife) Maybe a small diameter fid or pusher-rod would help push it. If you could get to the knot it should be possible to work a replacement line in. Also perhaps a pry bar (use gently with caution) would allow you to shift the CB a little to one side and give more space on the side with the knot. It might help to shove a flat thin metal bar (available in a hardware store) to remove marine growth to allow full space.

Also, I agree you should fold the boat -- that should raise the center hull quite a bit. This is not an issue on the 1000 or 1200 -- the CB is mostly dry in the trunk and needs to be only partially up to access the attachment point on the 1200 or 1000.
Larry - Former Owner DF-1200
EarthBM
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Post by EarthBM »

Don't think this forum allows direct image posting, the picture is here: http://img842.imageshack.us/img842/3179/cbdownhaul.jpg

It did not feel that there would be space to get a knot out of the side, but I haven't tried it.
Ivan -- DF 35 #29 "Lykke"
Double Horizon
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Post by Double Horizon »

EarthBM wrote:Don't think this forum allows direct image posting, the picture is here: http://img842.imageshack.us/img842/3179/cbdownhaul.jpg

It did not feel that there would be space to get a knot out of the side, but I haven't tried it.
If you can pry the board away from the access side (without putting too much stress on the trunk) you might be successful with a small metal push fid and hook (maybe the kind of dental hook used to remove packing from stuffing boxes). They should have made this an easy job without removing the CB -- ropes eventually need replacement. This isn't an issue on the other Dragonfly models I've owned.
Larry - Former Owner DF-1200
penryj
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Post by penryj »

I was able to prise a sail batten down one side of the board, enough to create the space for the old knot to be pushed out.
Then threaded the new downhaul line back through. Problem was the new knot would not compress as much as the old one so at present the knot just rests on the edge of the board. This doesn't seem to restrict the movement of the board so I wonder whether over time, the knot will compress and then slip into place.
I wonder whether a better solution would be to use a piece of dyneema core through the centreboard hole, somewhat like a lashing and then fix the covered line to that, maybe using a small static lashing block?
Penry

DF35-25
Gwas Y Neidr
Steve B.
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I'd stick with the knot.

Post by Steve B. »

I bet it will compress over time.
Dyneema is good for tension, but not so great with chafe.
Double Horizon
Posts: 440
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Re: I'd stick with the knot.

Post by Double Horizon »

Steve B. wrote:I bet it will compress over time.
Dyneema is good for tension, but not so great with chafe.
According to Practical Sailor's testing, Dyneema is more chafe resistant than any other form of line.
Larry - Former Owner DF-1200
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