mast rake problem

Moderator: GreenLake

Postby Jeepman252 » Sat Aug 27, 2011 5:38 pm

Thanks Tim,

Must be a long day for me, I'm at work and I posted that a UPS was the same as a GPS... Ugg... :oops:

Someone send me home! :D
Larry
'83 DSII
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Postby TIM WEBB » Sat Aug 27, 2011 11:19 pm

Working instead of sailing on a Saturday?!?!?!

Guess ya gotta do what ya gotta do ...

There's a thread somewhere on here about the UPS. jdoorly flies one, and others have shown interest ...
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Postby talbot » Tue Sep 06, 2011 1:39 am

Thanks for this discussion. My boat has somehow arrived at a neutral helm by my trial and error with shroud tension. But I would second the comment that heel is critical, especially in light air. I've been experimenting with letting the boat sail itself for extended periods, the helm held (more or less) in place with the hiking stick nudged against the seat back. Once the boat is balanced, usually on a beam reach or deeper, I find a can do all my trim by moving weight port or starboard. If I stand, it feels a bit like skiing--the boat turns away from the weighted leg. Besides being a fun diversion, the exercise convinced me that the effects of any rig adjustment are going to be specific to a particular configuration of crew weight.
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Re:

Postby ldeikis » Mon Sep 07, 2015 9:37 am

Hauling this one out of the archives to build on.

Recent dismasting at the tabernacle was fixed by cutting off the damaged bits and ordering a longer "bottom" from Dwyer. New shrouds, new tabernacle, and I'm good to go. Am trying to sort out a (perceived) new excessive weather helm. I've read the NS tuning guide and the forums pretty extensively. When I based my rake on the NS to-transom measurement, I had really aggressive rake to eye, and horrid weather helm. After reading Mike's suggestion:

Mike Gillum wrote:I would start by getting the Mast plumb in the boat by attaching a Plumb-Bob weight to the schackle on your Main Halyard, launch your boat, and with your boat loosely tied to the dock in calm water end-up with the weighted Main Halyard hanging...


...I did so and found the mast head was somewhere above the cuddy lip, some 14" aft of the partner. I loosened my shrouds and cranked on the tension up front using the winch and was able to get it forward to about 6" or so of offset before I was afraid I was going to tear something out of the boat. I still feel like I have inappropriately strong weather helm, though much better now. This boat will never be a competetive racer, but I'd like it to sail as fast and balanced as reasonable. I'd like to achieve a little less rake, however, I'm out of adjustment at the shrouds--theyre as long as they get. I have a little but more room on the forestay--it has maybe another 1/2" before it's all the way tight-- but I'm wary of trimming the mast shorter because I'm afraid even a tiny bit of material removed will make the forestay too long to get good tension. I would also prefer to find a solution with the adjusters in their range to allow for future tweaks and stretching. Other factors worth mentioning: the mast step is already shimmed up 3/4" on a rectangle of wood by a previous owner. I don't know why--whether to correct for a previous dismasting, to deal with stripped mast step screws, or to achieve a position slightly out of line with the stub under the cuddy? It appears to line up with the stub as best I can tell. Also this boat used to have a CB that only went down about 45 degrees, and I have to wonder if a PO didnt correct for that change in CLR by moving the mast?

Questions:
If other people have plum-bobbed their masts, about far back from the partners is your head when the boat's on her lines? I've been measuring rear of the sheave up top to rear of the mast at the partner, which ought to be the same as on-centers. This would be really useful information to understand if I am way off here.

I've read on the forum that moving the step forward/back in the cuddy only affects rake on keelson stepped masts, but that on boats with mast hinges, the lower part only provides support. I can not wrap my head around how this could be true--it seems like if I scoot the base aft a little bit, it should be create less rake up top hinge or no hinge. Am I missing something? BUT, this will still present me with the same issue regarding shroud/stay length won't it?

Last question: I know that sailing the boat flat makes a huge difference. I don't seem able to do that--I'm usually singlehanding (or with a labrador, who exacerbates the problem by sitting on the leeward bench) and I sail with pretty robust tides and river current. If the breeze is light enough for me keep the boat flat, I'm barely moving through the turbulent water. If it stiffens up enough to have some fun, even with my feet in the straps fully hiked out I'm nowhere near flat--this is when I'm so frustrated with the giant brake of a rudder I'm holding. Is this simply my problem and the rake and helm is fine and the issue is simply that the unballasted daysailer is poorly suited to singlehanding in this location?

The boat's on a mooring and is a pain to haul out, but I'm open to doing so if I understand what I'm trying to do. In the meantime I'm still enjoying sailing her!

Thanks for any input,

Luke
'74 DSII sailing Haverstraw Bay and the lower Hudson River
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Re: mast rake problem

Postby talbot » Mon Sep 07, 2015 12:45 pm

I have a '73 DS II. I have not plumb-bobbed my mast, but by tweaking the shrouds and stay, I got it to a point where it has a neutral helm in most conditions. Could it be that your shrouds are too short or your stay too long? For what it's worth, my Johnson stay adjusters are set to 3.5. The bow has a newer turnbuckle without graduations, but as I recall, another DS I owned had a Johnson adjuster on the forestay, and I also set that to 3.5.

I also often sail alone, often on windy days, and do have a problem keeping the boat from heeling beyond 15 degrees (the point at which the speed really falls off). My solution was to get double reef points on my sail. I find that the boat goes faster under less sail because I can keep it flatter in the water. I also had an old jib cut down to make a 95% heavy air foresail (I think the standard is a 115). You can also reduce heel and weather helm by raising the centerboard part way. I have the old-style CB downhaul that comes out of trunk just aft of the jib cleats. I marked the top of the trunk at 15-degree intervals so I can tell how much board is in the water.

Keep in mind that any boat is designed for optimal performance with a particular wind range and particular crew weight. I am guessing that optimal for the DS is two people on the rail in eight knots under full sail. One person trying to beat into a 20-knot wind is going to be moving slowly, reefed down, heeled over, hiked out, and very wet. Also, in my opinion, very happy. This is a great boat for whitecap days. Get that rigging adjustment figured out so you can enjoy them.
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Re: mast rake problem

Postby ldeikis » Mon Sep 07, 2015 8:41 pm

The shrouds are brand new from Rudy so they should be the right size. The forestay is upgraded, but also from Rudy just not right this season. The mast height, though, is a wild card since I had to cut some damaged extrusion off each end and use a longer stubby part (below the hinge) than one usually would. I have a single reef point which I use almost every time I go out. My sails are in sad shape but I will be sure to get double reefs in the new set one day.

I'll play around with raising the board part way. That also occurred to me, but due to some repair/modifications of the original cabling it's all or nothing right now (I'm using a bungee to hold the downhaul taught, which seemed prudent, but in retrospect having some in between clearly would be clever). It's just a matter of switching some blocks around and drilling a new hole in the cuddy wall and I should have that finesse.

I certainly enjoy the windy ones, so long as the chop doesn't get so bad that it kills the boat speed. Was out today and for a while it was so rough that if I dropped straight down a trough I could stuff the forestay through the face of the next wave. Also not a fast way to sail. Lost the dog twice.

Luke
'74 DSII sailing Haverstraw Bay and the lower Hudson River
ldeikis
 
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Re: mast rake problem

Postby talbot » Mon Sep 07, 2015 9:14 pm

DOB is an underestimated marine hazard. We installed a Dachshund Mini on our boat for ease of retrieval by tether or the nifty little handle they put on the top of canine PFD's. The other issue while sailing in heavy weather with just her is that she knows she can go into duffle while I'm hiking out and eat all the snacks. None of this "sun is over the yardarm so the bar is open" for her. As far as she is concerned, the sun is always over somebody's yardarm somewhere. But I suppose that's why she enjoys sailing.
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