| Rudder adjustment or Mast rake #55100 08/12/05 09:10 AM 08/12/05 09:10 AM |
Joined: Jun 2005 Posts: 149 Long Island, NY Catius OP
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Posts: 149 Long Island, NY | So I am sailing my recently acquired Mystere6.0 now. I find it has a lot of weather helm. I have a few questions.
1.How much weather helm is too much? I find myself really pulling the tiller fairly hard on a close reach / reach. If I let go the boat turns in the wind within about 5 seconds.
2. I have gotten some advice on tuning - my mast meanwhile is quasi straight vertical. Rudders are raked as much forward as they go. What else can be done?
3. What is the difference between the mast rake / rudder rake remedies? When should you use which remedy?
Thanks
Thomas
Thomas
Mystere 6.0
| | | Re: Rudder adjustment or Mast rake
[Re: catman]
#55102 08/12/05 04:50 PM 08/12/05 04:50 PM |
Joined: Jun 2005 Posts: 149 Long Island, NY Catius OP
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Posts: 149 Long Island, NY | No - haven't tried...what should I look out for?
Thomas
Mystere 6.0
| | | Re: Rudder adjustment or Mast rake
[Re: Catius]
#55103 08/12/05 06:18 PM 08/12/05 06:18 PM |
Joined: Jul 2001 Posts: 1,200 Vancouver, BC Tornado
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Posts: 1,200 Vancouver, BC | Raking the mast more aft will place the center of effort from the sail plan further back, putting more load on the rudders, making weather helm worse. Raking mast further forward should do the opposite. Raking the rudder blades forward will not change the forces on the blades, just how much mechanical leverage you need to apply to keep the boat going straight...think "power steering". In extreme cases, the loads can be so high on the blades that they ventilate regularly...a bad thing!
How is your jib setting when you feel the weather helm? Too lose? Remember, the main will tend to make the boat round to weather while the jib helps counter act this, bringing the nose off the wind. Perhaps you've got the main oversheeted for the course and conditions, while the jib is not doig it's fair share. What happens if you pay out the traveller a few inches while reaching? How are the centerboard & rudder surfaces? Are your rudders aligned correctly?
Mike
Mike Dobbs Tornado CAN 99 "Full Tilt"
| | | Re: Rudder adjustment or Mast rake
[Re: Tornado]
#55104 08/12/05 06:32 PM 08/12/05 06:32 PM |
Joined: Apr 2005 Posts: 473 Panama City, Florida Redtwin
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Posts: 473 Panama City, Florida | I had the same problem with my Nacra 5.2. I haven't tried the one rudder up trick. I knew that that would reduce drag but I will try it to see if it reduces weather helm too. My main problem is that due to the rope-a-dope rudder system on my Nacra, I am having problems getting the rudders all the way down. Even so, the helm is not unbearable.
-Rob V. Panama City Nacra 5.2 Rob V.
Nacra 5.2
Panama City | | | Re: Rudder adjustment or Mast rake
[Re: jfint]
#55106 08/12/05 08:40 PM 08/12/05 08:40 PM |
Joined: Feb 2004 Posts: 1,012 South Australia Darryl_Barrett
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Posts: 1,012 South Australia | Mike has it spot on! Weather helm is caused from the balance of the sails in relation to the rudders, hulls, centreboards OR more correctly, the relationship between the centre of lateral resistance of the boat to the centre of effort of the sails. If the CE is too far forward (relative to the CLR) then lee helm is the result, too far back and weather helm occurs. A crew can also effect the helm (as most sailors are fully aware), when the crew is forward the bow goes down, the stern comes up and the CLR "moves" forward, boat point higher – weather helm -, similarly when moving back the reverse and weather helm reduces. IE lee helm - Rake the mast back excessively - weather helm - too far forward - lee helm -. Let the main off to windward and pull the jib on - lee helm (or the more noticeable result, - the boat sails from a beat onto a reach and all the way down to a run), pull the main on, let the jib off – the boat sails itself “up” even to the point that some boats will actually tack without any helming by the crew. IE weather helm. | | | Re: Rudder adjustment or Mast rake
[Re: Will_R]
#55108 08/13/05 07:29 PM 08/13/05 07:29 PM |
Joined: Apr 2005 Posts: 473 Panama City, Florida Redtwin
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Posts: 473 Panama City, Florida | So how can I get my Nacra 5.2 rudder system to let me lower the rudders all the way. It sailed beautifully for the first part of the day today (wind 5-7 MPH). Later, the wind kicked up to close to 10-12 MPH and I was armwrestling the rest of the day. Any ideas?
-Rob V. Panama City Nacra 5.2
Rob V.
Nacra 5.2
Panama City | | | Re: Rudder adjustment or Mast rake
[Re: Darryl_Barrett]
#55109 08/13/05 09:39 PM 08/13/05 09:39 PM |
Joined: Jun 2005 Posts: 149 Long Island, NY Catius OP
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Posts: 149 Long Island, NY | Thanks everyone...At this point (with my rudders already raked forward & mast vertically straight), it sounds like I need to play more with the sails. Maybe pay out the main traveler a bit, sheet in the jib more tightly. Moving the crew aft on a close reach is going to turn me into a transom dragger... I was not clear on how lifting a rudder would help? Will try some next weekend...thanks.
Thomas
Mystere 6.0
| | | Re: Rudder adjustment or Mast rake
[Re: Catius]
#55110 08/14/05 07:23 AM 08/14/05 07:23 AM |
Joined: Mar 2002 Posts: 3,355 Key Largo, FL and Put-in-Bay, ... RickWhite
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Posts: 3,355 Key Largo, FL and Put-in-Bay, ... | Keep in mind that the Mystere is infamous for having a bad rudder system. My son sailed one in the Worrell 1000 and renamed the boat "Mis-Steer." I had one years ago and the rudders were all crooked after they came out of the mold. This makes for lee helm on one tack and weather helm on the other. Just take a good luck and eyeball the actual rudder blade. You might just find the rudder blade is not true. The other major problem I had with the rudder system is it kept kicking up on deep water for no reason.., and then when I came to the beach they would stay locked down. Another Worrell 1000 war story is the Mystere that hit the beach for the finish and instead of the rudders kicking up, the stern tore off the boat.
As for how far under the boat your rudders are, you need use a straight edge on the stern of the boat and draw a line on your rudders -- both rudders. The percentage of the rudder that is forward of that should be the same on both rudders. If not, that is one of your problems. I can't recall what the best percentage should be, but around 15-20% or so of the leading edge of the rudder should be ahead of that line. If it is too much, you will get some pretty radical rudder reactions -- lee helm, then suddenly weather helm.., than back to lee helm, etc. If it is too little, you will have lots of weather helm. Good luck, Rick | | | Re: Rudder adjustment or Mast rake
[Re: RickWhite]
#55111 08/14/05 11:04 AM 08/14/05 11:04 AM |
Joined: Apr 2005 Posts: 473 Panama City, Florida Redtwin
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Posts: 473 Panama City, Florida | I don't know that I would ease the main and the trim the jib, that would cause your jib to backwind your main and you will lose a lot of power. Try flattening the main so that you can depower it without pinching off the slot. I guess you would have to ease the traveller and sheet the main harder, and tighten up the downhaul and outhaul. That way you would still have good flow over the leeward side of the main, but the main won't overpower the jib so much. This of course is all theoretical thinking coming from a relative newbie. I'm going to try it next weekend to see if it helps. I spent a lot of time yesterday with the traveller almost centered (3" off center) and the sail was very full and twisting. It gave me great power reaching, but when it came to beating, I had to curl up and use my knees to help hold the tiller and the sheet. Off topic a little: I remember a while back having a thread here about cleating or not cleating the main. Yesterday was the first time I was on the boat all day long. I learned the benefits of cleating in. I am now a cleater. I did fly the hull pretty high a couple of times before I could uncleat, but in the light to moderate air we were in, it was manageable. I don't think I would use the cleat in heavy or gusty winds.
-Rob V. Panama City Nacra 5.2 Rob V.
Nacra 5.2
Panama City | | | Re: Rudder adjustment or Mast rake
[Re: Redtwin]
#55112 08/14/05 11:32 AM 08/14/05 11:32 AM |
Joined: Jul 2001 Posts: 364 Andrew
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Posts: 364 | So how can I get my Nacra 5.2 rudder system to let me lower the rudders all the way. It sailed beautifully for the first part of the day today (wind 5-7 MPH). Later, the wind kicked up to close to 10-12 MPH and I was armwrestling the rest of the day. Any ideas?
I used to tie stopper knots in my holddown lines; the PivMatics still worked fine. Later I learned that I could release the PivMatic, pull the rudders down, start to cleat the line, and push the PivMatic down to "lever" the line tighter. Having good cleats and good line, that match one another for size, helps too.
Andrew Tatton
Nacra 20 "Wiggle Stick" #266
Nacra 18 Square #12
| | | Re: Rudder adjustment or Mast rake
[Re: Andrew]
#55113 08/14/05 06:08 PM 08/14/05 06:08 PM |
Joined: Apr 2005 Posts: 473 Panama City, Florida Redtwin
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Posts: 473 Panama City, Florida | I'll give that a shot before I actually re-do the system, but I'm afraid to apply any kind of leverage to the line. My boat is old and crusty and my budget doesn't allow for very many repairs. I'm thinking of re-doing the lines with some suggestions from Buzz on TheBeachcats.com. -Rob V. Panama City Nacra 5.2 Rob V.
Nacra 5.2
Panama City | | | Re: Rudder adjustment or Mast rake
[Re: Catius]
#55114 08/15/05 11:39 PM 08/15/05 11:39 PM |
Joined: Jun 2002 Posts: 1,658 Florida Suncoast, Dunedin Caus... catman
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Posts: 1,658 Florida Suncoast, Dunedin Caus... | I was suggesting one rudder at a time to see if the boat acted the same or if there was a difference in the two. If one feels good and the other doesn't then it could be a rake issue or a blade could be bad like Rick mentioned. If the boat feels good with either one down and bad with both down then it could be an alignment issue.
Thomas check your PM.
Last edited by catman; 08/15/05 11:52 PM.
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