Lee helm

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Lee helm

Postby Tipster1 » Tue Jun 25, 2013 7:38 am

I've only taken DS II out once in 8-10 kts and immediately notice neutral to lee helm, increasing in gusts. Side stays slacken more than I'd like even though rig is taut when 1st raised. It is possible that this is original standing rigging. I intend to tighten side stays, but there is only another 1/2 " left to tighten in turnbuckles so I am already wondering (Q#1) what other adjustments can be made? Otherwise, I assume I am looking at new standing rigging, leading to the question (Q#2) of how do I re attach new shrouds to mast since attachment seem to be riveted on?

Suggestions and advice?
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Re: Lee helm

Postby K.C. Walker » Tue Jun 25, 2013 9:47 am

That is an odd scenario for close hauled. Most of the time sailboats develop more weather helm as the wind increases and the boat heels over. Are you sure that your centerboard is all the way down?

If the boat is neutral at 8-10 but the lee helm increases with gusts, somehow either your center of resistance is moving aft or your center of effort is moving forward. If you are sure your centerboard is all the way down and staying down, then it would appear to be the rig. ½ inch of travel on the turnbuckles should be enough to rake your mast back enough to make weather helm, I would think.

I use a fair amount of rig tension, enough that I need 5:1 tackle on the jib halyard when setting up so that I can attach the forestay. Not everyone does this, though enough of the champion sailors do use high rig tension that I started adopting it. What this does is stabilize your rig and can give you more control over your sails. In particular it limits the amount jib stay sag. If your rig is slack, when you are close hauled and have a lot of main sheet tension on you are pulling the jib stay tight. When a gust hits and you release the main sheet the whole rig moves forward and allows the jib stay to sag. This powers up the jib just as you de-power the main which could cause lee helm.

You should definitely inspect your standing rigging and if you have any doubts it's prudent to replace it. The part that is riveted to the mast is called the tang and does not need replacing, in most cases. You will find that if you look carefully the shroud has a clevis pin which attaches it to that tang.
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Re: Lee helm

Postby seandwyer » Tue Jun 25, 2013 11:02 am

+1 to everything K.C. mentioned.

If I were you and was not sure how old the rigging was, I would replace it. A set of stays from D&R is very affordable compared to a toppled mast. I would especially replace it if it is still the 3/16" rigging. The consensus is that that size was never really stout enough. If you buy new rigging locally, make sure to ask for 1/8". When I bought my boat I had the older rigging and the diamond stays in place. I constantly was worried about it because I just wasn't sure of it's condition, but it sure had a lot of "memory" bends in the wire when I took the mast down. Finally a single wire in one of the shrouds broke and I knew I had to bight the bullet. After the new stuff went up, I felt silly for not having done it sooner--it took care of any fears I had. Removing the diamond stays really helped as well. The mast bends more now and the sail shape improves as a result. Putting the new stuff up is easy--comes the precise size you need and all clevis pins fit the existing tangs. If you're concerned about how easy it will be to adjust, be sure to buy the full turn buckles. Make sure you inspect the rivets in the tangs, too. While you are at it, you may as well replace the spreaders with the higher strength ones from D&R as well. I couldn't tell you how many times I bent and broke spreaders until I bought the ones from Rudy. The ones he sells are worth twice what he charges considering the aggravation they have saved me.

I keep my rig pretty tight too, but I don't know exactly what it is. I'd love to have a Loos gauge, but so far haven't been able to bring myself to putting down the dough for a tool I will use so little. I just need to find someone in the boat yard that will let me borrow it! :D
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Re: Lee helm

Postby Tipster1 » Tue Jun 25, 2013 5:35 pm

Thank you both.

I'll definitely will confirm and monitor CB position on next sail, KC. I hadn't thought of that, but we sail in shallow waters, so occult board retraction could happen. Because of sand bars, I am hesitant to cleat the CB down haul firmly, but may rig up some bungie apparatus. 5:1 jib halyard tension to rig!!! I am quite confident in putting huge amounts of DH tension in windsurfing sail (6:1 purchase augmented by full leg press) but still timid with this boat. But then, my windsurfing mast is 90% carbon fiber. Guess I need to put some back into it.

Closer inspection of shrouds reveals appropriate clevis pins at mast, so replacement of 3/32 (which is what it appears to be) wire with 1/8 makes all sorts of sense and should be simple. Replacement of spreader bars and boots (just for looks) makes sense, too. That should stabilize the rig quite a bit. :D

What are Diamond Stays?
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Re: Lee helm

Postby seandwyer » Tue Jun 25, 2013 6:28 pm

What I am referring to by "diamond stays" are a second set of shrouds mounted about mid mast, going over another, smaller set of spreaders, then terminating just shy of the very top of the mast. When installed they made a diamond shape with the mast in the center. They provided upper mast support and were the way many earlier DS boats were rigged. At the time (so I have been told) a stiffer mast was thought to be better, but by today's standards that is false--more flexible is thought to be better for performance. Most people new to the boat are advised to remove these stays, which I did.

Your description above tells me you have a DS 2 based on the center board lift system, so this isn't something you would have ever had--at least I don't think so. To find out, see if there is any odd hardware left on the mast, or inexplicable rivet holes where hardware had been. If so, it could be from diamond stays.
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Re: Lee helm

Postby GreenLake » Tue Jun 25, 2013 7:26 pm

All discussions of lee/weather helm assume that your sails are correctly trimmed. If your main is not sheeted in far enough, then the primary sail driving the boat would be the jib. That kind of scenario should introduce lee helm (and logically it would get worse in a gust).

I mainly mention this because, from a distance, we can only judge the facts as given, so something that would never ordinarily occur would be missed, if not mentioned. Probably unlikely because I think the main would look seriously "unhappy".

Given that this is a DS2, where you cannot directly see from the angle of a CB handle (as for a DS1) how far the CB is deployed, I'd be comfortable in looking for the issue there, but you should rule out wildly incorrect sail trim as well.
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Re: Lee helm

Postby K.C. Walker » Tue Jun 25, 2013 8:02 pm

Another aspect of the higher rig tension is that it induces some prebend, just like you're after with a windsurfer rig. Your mainsail has a luff round, not as extreme as your windsurfer sail, but still there and can be matched by prebend. This gives you some flexibility in mainsail power, just like a windsurfer. A lot of the principles of windsurfing apply to this boat. You can steer the boat somewhat like you would a windsurfer by moving the center of effort fore and aft. The mast, obviously, stays put but sheeting in the jib and sheeting out the main is a lot like moving the rig forward on a windsurfer.

I've also had that occult centerboard raising phenomenon, embarrassingly so on occasion. Last fall I was having a grand old time planing back and forth across a shallow bay, almost keeping up with a slow windsurfer on occasion, when I went to tack just windward of a very expensive boat and… no go. I had just enough time to throw the board down, sheet in the jib release the main and get the boat to spin around into a jibe. My boom missed the folks sitting in the cockpit at cocktail hour by at least 10 feet (it seemed). I apologized on the way by and they just waived.

Those spreader boots are actually functional. They definitely help to keep from wearing a hole in your jib.
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Re: Lee helm

Postby TIM WEBB » Tue Jun 25, 2013 9:12 pm

Actually GL, it is quite easy to see at a glance how far up or down the CB is on a DS2 by simply observing the position of either the UH tackle on the cuddy floor or the DH tackle between the CB trunk top and the cuddy lip or both ...

KC: how would the ends of the spreaders ever put a hole in your jib? The jib never gets close to there. Or are you referring to your UPS? I could see where the ends could poke holes in the main, and I have the boots on there to prevent such damage ... ?
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Re: Lee helm

Postby GreenLake » Tue Jun 25, 2013 9:24 pm

TIM WEBB wrote:Actually GL, it is quite easy to see at a glance how far up or down the CB is on a DS2 by simply observing the position of either the UH tackle on the cuddy floor or the DH tackle between the CB trunk top and the cuddy lip or both ...

Tells you how little I know. I like my handle!
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Re: Lee helm

Postby K.C. Walker » Tue Jun 25, 2013 9:52 pm

Tim, you're catching everybody tonight! :-) Yes, it's the main that one needs to be concerned about wearing a hole in, or snagging ones spinnaker, or in my case, yes, my UPS.
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Re: Lee helm

Postby TIM WEBB » Tue Jun 25, 2013 10:54 pm

Just keeping everyone honest KC! :twisted:

The only reason I mentioned the ability to see at a glance the CB position on a DS2 was that last weekend I was crew for ChrisB on his boat while we sailed to Sebastian City Docks to collect my wife and daughter, and I noticed that his boat has a marked difference in "travel" of the CB controls compared to my boat, and ours are only one model year and less than 100 sail numbers apart. Must be a slight difference in where the CB control tangs are mounted on his boat compared to mine. Another interesting difference: his boat has the CB wedges, whereas mine does not: O'Day made that change sometime between late '79/early '80 ...
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Re: Lee helm

Postby Tipster1 » Wed Jun 26, 2013 7:43 am

Thank you all for your interest and feedback. Many windsurfers beyond the beginner stage get very techy about their rigs and we are always tuning and re-tuning for conditions. CE and CLR are under constant study. Coolest thing is that with the right mast flex pattern, the sail sheets out and in automatically by twisting off at the head in gusts. We just ride it and speed up.

Yes, this is a DS II. and there are no signs of additional hardware on the mast. No diamonds for me.

I doubt that my lee helm came from sail trim since the situation persisted even with an almost luffed jib. I spoke to former owner last night and he revealed that he had an unexpected encounter with a power line when boat was on a trailer and the mast was pushed aft to the point that the fore-stay let loose. It is still a bit unclear to me as to exactly what broke. In any case, the mast collapsed aft and the tabernacle was damaged. After repair the mast was 1/2 to 3/4 " shorter. This would explain why I was unable to tighten side stays and rake mast aft enough. When opportunity arises I shall be measuring mast and shrouds very carefully, as well as inspect fore-stay attachment.

Former owner had intended to put a 1/2 to 3/4" block under mast step on keel to compensate, but never did. I imagine that the cuddy top could lift, but that would be inconsequential. I am just thinking of using current measurements, discussing with rigger and probably get slightly shorter stays. What do you all think?
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Re: Lee helm

Postby K.C. Walker » Wed Jun 26, 2013 9:38 am

My mast stub got shortened by about the same amount because of dis-mastering the very first time I took the boat out (a seemingly good turnbuckle bolt broke). I shimmed it with some ¾ ipe decking. Then I made it into a "feature". All of the mast and tubing was a little chewed up and corroded from previous damage. I ended up cutting off a total of an inch to clean everything up.

Again, we have the same principles as your windsurfer rig. When the wind is up and gusty, we want the rig to be flexible so that it will twist out on its own for gust control. So, the "feature" I made is a track so that I can slide the mast stub base forward and aft. What this does is to make the tabernacle base tilt forward when I pull the mast stub base back. I only use the rear pin in the tabernacle. With the rig tension is on this helps to induce low mast prebend which really gets the rig more flexible. I then use a powerful boom vang. When I pull on the vang, when the tabernacle base is tilted forward, the mast bends easily and the boom "floats" from the vang attachment point, making the boom flexible, as well. With this setup, when a gust hits, the boom automatically flexes up, as does the mast flex, allowing the leech to open and twist automatically.

I would definitely inspect everything in the standing rigging carefully. Even if the previous owner was honest, he may not been competent.
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Re: Lee helm

Postby Tipster1 » Wed Jun 26, 2013 11:10 am

Reply and advice appreciated, KC. Hopefully, aluminum mast isn't as whippy as our FG masts. Windsurfing went through a short aluminum mast phase, until it became obvious, aluminum was too rigid, fragile, and heavy.
I am having a hard time imagining your new set up. What is 3/4 ipe decking? And you installed it where? Between tabernacle fitting and deck/cuddy top?

When you pull mast base back (I assume just a little so it is still over support inside) and harden up the vang. I picture a fair amount of leach tension bending mast back. I am surprised using just the rear pin on the tabernacle lets the mast tilt forward very much.

Inspection of fore-stay attachment is first order of business when I return to boat. What I recall, however is that the area right under the bow is enclosed so I won't be able tyo see much, but then again, my memory isn't what it used to be.
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Re: Lee helm

Postby K.C. Walker » Wed Jun 26, 2013 11:59 am

DS1 and DS2 normally have a full-length mast that goes through the partner opening on the cuddy roof to the keelson or cuddy floor. This is where I installed the three-quarter inch decking shim. Ipe is a tropical wood sold at lumber yards for decks which I had scraps of. When a tabernacle is installed, the mast is cut just above the cuddy roof and installed between the two pieces. The lower part of the mast (what I referred to as the mast stub) is what I move only at the base, so it tilts the tabernacle plate that is attached to the top of this stub.

Of course the aluminum mast is not as whippy. What I'm saying is, what you know from windsurfing applies here. The details are obviously different but controlling mainsail shape is similar in principle. Now kite boarding… Not so much.

It's interesting to think about the differences between the two kinds of sailing, though. If you live in an area where there's plenty of wind, and you mostly sail solo, and you like exciting sailing, it's hard to beat windsurfing. On the other hand, if you want to go out with a friend or there's not enough wind to windsurf, and you enjoy moderate wind sailing, you can have a grand time in a DaySailer. Or, obviously, have both setups… the best of both worlds!
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