DSII centerboard pennant reconfiguration

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DSII centerboard pennant reconfiguration

Postby JeremyS » Mon Aug 01, 2022 3:47 pm

Hi all,

New member to the forum. This past Fall I bought a 1981 DSII that DS Forum username: elcapitan did a great job restoring back in 2020 (he posted about it here at the time). Now I'm picking up where he left off, and one of my next planned upgrades is the centerboard pennant.

At the moment, it's really tough to get up the last 10% or so of the way. Previous owner had a tough time with it, too, but it wasn't too much of a problem for him because he had it in a roll-off dock. I'm trailering the boat, though, so I like to make sure it's 100% up before it gets anywhere near the trailer. My current kluge-y fix is to haul it up the last 10% of the way with a ratchet strap (see pic) which works great. But it would be even better to have it rigged up the right way and not need to keep a ratchet strap in the cuddy.

I read the threads on here about this problem, and pulled the great images some of you posted about routing all the cables properly. This is what mine looks like now...

298129822983

There are a couple mechanical advantage problems that I can see here. One is that the uphaul cable takes a turn around the block by the mast step, rather than terminating a few inches in front of the trunk and switching to braid. The other is that, in this configuration, there's no cascade, and the subsequent heft that provides. As you can see, one eyestrap remains on the deck from the original configuration, and the screw holes from the other are visible on the starboard side.

Have any of you ever tackled (pun more or less intended) this before? The centerboard seems to be physically fine - it was restored two seasons ago, and it happily clunks into place once enough force is applied to it (with that ratchet strap). I just don't think this current setup provides enough force to hoist it up those last few inches. What do you think?
DSII # 10811 "Moment's Notice"
Madison, NJ
JeremyS
 
Posts: 3
Joined: Fri Jul 08, 2022 11:57 am
Location: Madison, NJ

Re: DSII centerboard pennant reconfiguration

Postby GreenLake » Tue Aug 02, 2022 12:54 am

That last bit of sideways pull using the ratchet is easily a mutiple of the force achieved by the purchase by itself. When you pull at a very shallow angle, which I think the ratchet probably starts out at, then the multiplication is easily a factor ten (10)! That's enormous. If that is truly required to get the CB over some sort of hump, or sticky point, before it "clunks" home, then I think you are right to be asking questions.

You could draw a diagram of what the CB and cable look like inside the trunk at the moment you need that much extra force. If you apply the lever arm represented by the curve of the CB and the lever arm out to the center of gravity, together with the max weight of 25lbs you might find out whether the force you are applying is in line with the counter force based on weight alone, or whether you must assume that the CB is actually sticky or otherwise has a point where extra friction acts on either the cable or the pivot or both. (Or possibly the side of the CB).

It could be that the CB has shipped water, or it's one that has the design that lets water flow in, but also should allow for it to leak out again - there may be an opening that's blocked. Also, does this happen only in the water, or does it also happen with the boat on saw horses (piles of tires)? Does it happen when the boat is on its side?
~ green ~ lake ~ ~
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Re: DSII centerboard pennant reconfiguration

Postby JeremyS » Tue Aug 02, 2022 9:50 am

It happens pretty much all the time. When it's on the trailer and I can get under there and see it, it's about 6 inches of centerboard left hanging down. But it's just as tough to pull up that last few inches in the water as out. Though, if I slide under there like a mechanic and just push it up the last few inches into the trunk with my hand, it's not sticky at all. Pivots nicely.

This is the diagram that another user posted that I want to try out. And, considering the presence of an unused eyestrap (and screw holes where the stand up block once was) on the deck inside the cuddy, the boat DID have this setup at one point.

2988

We had the boat on the water Sunday, and before pulling up the centerboard and hauling out I marked the fully down position on the steel uphaul cable, so I know where it could be cut shorter and a new eye swaged into it. It's crazy long at the moment (like 24" or so, as you can see) and it takes a turn through a block, which can't be efficient. In the diagram it terminates a few inches forward of the trunk with a becket block, which then cascades into the 5/16" dacron. That's a lot more power than what I have right now.

And, needless to say, that downhaul basically does nothing as it is right now. It's like one of my 8 year old's sneakers whose laces are so wildly tangled up in knots that they now essentially loafers. I'd love to make that arrangement in the diagram happen, with a single length of 5/16 dacron controlling both uphaul and downhaul functions.
DSII # 10811 "Moment's Notice"
Madison, NJ
JeremyS
 
Posts: 3
Joined: Fri Jul 08, 2022 11:57 am
Location: Madison, NJ

Re: DSII centerboard pennant reconfiguration

Postby GreenLake » Tue Aug 02, 2022 1:56 pm

First: because there's no resistance pushing up the CB, the suspicion is on friction in the cable.

Points to check: where the cable goes through the double(!) CB wall. Some boats report that their cable has sawed a slot into the fiberglass that adds friction, sometimes invisibly on the inner trunk wall (I believe the angle of the uphaul changes slightly if the top of the CB is not a perfect semicircle around the pivot, which would change the alignment inside the CB trunk and means friction can change just at the point where you need the most force to overcome gravity).

Also, by all means check out your block. If it's correct for wire, the loss shouldn't be too great, but see whether it binds under strong loads, for example. (Everything seems to happen at the point maximum force is needed).

Before you cut your cable, make sure that it can run through the entire range w/o running into a block (the eye would not fit). Also, think about what will happen when you drop the CB out of the boat for repairs. Will you be able to get to the point where you can disconnect the cable from the CB, or will the shorter uphaul make that impossible).

A more long-term solution (after you ensure a smooth passage through the CB wall) would be to replace the cable by Dyneema (AmSteel). The rule of thumb is equal diameter for equal strength, so fit should not be a worry, but Dyneema runs much more easily through blocks than almost anything. As long as there's no chafe, it would also glide through the opening more easily as it's so slippery.

Hope these considerations are of some help.
~ green ~ lake ~ ~
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Re: DSII centerboard pennant reconfiguration

Postby JeremyS » Tue Aug 02, 2022 3:12 pm

Excellent suggestions, thanks. I'll give it a a look and see what I find. I've never actually tipped a DS on its side before. I spent a summer as the steward for fleet 67 up in MA (a million years ago) and helped a lot of people with their centerboards, but we had a hoist. Sure made it easy, haha.
DSII # 10811 "Moment's Notice"
Madison, NJ
JeremyS
 
Posts: 3
Joined: Fri Jul 08, 2022 11:57 am
Location: Madison, NJ

Re: DSII centerboard pennant reconfiguration

Postby GreenLake » Wed Aug 03, 2022 3:41 am

if you can tip with the mast up, it's easy: just pull on the jib halyard (but make sure the other side is firmly attached to the mast or boat). Don't pull on the main halyard, as that bends the upper part of the mast. Other than that, easy.

W/ mast down. you may need two people.

Some carpet/cardboard helps in protecting the gelcoat
~ green ~ lake ~ ~
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