weather helm
Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Dinghy development
Forum Discription: The latest moves in the dinghy market
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=2932
Printed Date: 18 Aug 25 at 8:09pm
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com
Topic: weather helm
Posted By: micmac37
Subject: weather helm
Date Posted: 06 May 07 at 8:59pm
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I was sailing my RS800 yesterday. It was force 4 and gusty. We have had problems with weather helm on and off. I expect some of it was to do with technique as we have not been sailing it perfectly flat due to the very gusty/windy conditions where we sail at this time of the year and desire to avoid windward capsize. In addition I have had to readjust the rig to ensure it is at class reccomendations. Yesterday the first race the boat was perfectly balanced and responsive. Despite not being perfectly flat the rudder was still manageable and light. In the second race there was a large amount of weather helm. The conditions and boat settings were the same. We checked the rudder and it was fully down. My biceps were tired from the constant pull unless the boat was perfectly flat/almost coming over on top of me. It felt like a boat with the rudder halfway up... Of notice was that the weather helm was much worse on starboard tack. Back onshore - the mast was central. The settings were correct (in fact mast ever so slightly underraked). The jib slot was open. - The rudder appeared to have a small stress fracture where it leaves the stock but I could not detect any bend at all. Any suggestions. At times we were sailing as if overpowered a bit. Could it be the main was simply too powered up compared with the jib ? However if I need to depower it I need more rake and that will surely give even more weather helm. Any suggestions ? Mike
------------- Sail well Feel Swell |
Replies:
Posted By: elmo
Date Posted: 06 May 07 at 9:30pm
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Something must have changed between the first and second races! Are you sure you have put the rudder together right? With RS rudders if you don't put the downhaul over the top of the metal posty bit (sorry bad description) in the stock then they won't stay down properly. So maybe would be fine the first race then if you hit a gust and there was more pressure it would start popping up? Maybe nothing but I have cursed the rudder (and my sore arm) with that sort of thing before. |
Posted By: Calum_Reid
Date Posted: 06 May 07 at 9:34pm
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was your rudder right down? thats the usual one ------------- 
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Posted By: radixon
Date Posted: 06 May 07 at 10:15pm
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Mike said it was down in his post. Another thought, when you said you checked, could it of got something wrapped around it or was that what you were checking? ------------- |
Posted By: Calum_Reid
Date Posted: 06 May 07 at 10:27pm
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You say that but it needs to be right down on rs boats or they can be unsailable. its rediculous the difference. -------------
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Posted By: Worthy
Date Posted: 06 May 07 at 11:35pm
Years ago in the Hobie 16 I got a similar stress fracture on the rudder and I got unmentionable weather helm. Water had managed to seep in throught the crack and soften the blade internally which made in flex under load. The only solution was to buy a new rudder. When it was in the water being used you could see the flex, but when it was on the shore you couldn't put enough load on to see any flex. Sounds like a similar issue to what you have. Edit: You could borrow a friends rudder to see if it is the rudder that is causing the problems. ------------- |
Posted By: redback
Date Posted: 07 May 07 at 3:50pm
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I'm sure it was 1 of 2 things. 1. you weren't sailing the boat as flat as you were in the morning. 2. the rudder was not quite right down. You'd be surprised how even the smallest change of angle here makes a huge difference. When I first had my Laser 4000 I experimented and found the thickness of a double layer of PVC tape on the abutment of the rudder made a huge difference to the feel of the helm. The abutment is the part of the blade which stops the blade from going down any further. Having discovered this I always make the rudder come down hard enough to make an audible clunk - if it doesn't I put it back up and have another go - its the only way to get a consistent feel to the helm. Alternatively it is just possible the hole that the bolt goes through is oversize.
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Posted By: Calum_Reid
Date Posted: 07 May 07 at 3:57pm
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Thats another RS one. The hole the rudder bolt goes through gets elongated and then all sorts of weird and wonderful things happen. We filled the 400's rudder up re drilled the hole and put a more hard wearing bush in to make a bit better. -------------
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Posted By: m_liddell
Date Posted: 07 May 07 at 4:03pm
Truth. This is why daggerboard style rudders are good. I have an RS800 rudder on my 14. I always pull the blade down with my hand and then do up the plastic wing nut thing, then I cleat the downhaul. Just using the downhaul means that the rudder blade can move back slightly since the rope moves back a bit as it cleats harder. |
Posted By: redback
Date Posted: 07 May 07 at 10:43pm
| Actually you'll find if the blade is not fully down you will also get leehelm amplified. So try sailing the boat very flat with the kite oversheeted, on a 4000 that produces leehelm. If the blade isn't right you'll be bearing away big time! |
Posted By: Calum_Reid
Date Posted: 07 May 07 at 10:47pm
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U can feel leehelm in most boats with the kite oversheeted (or main undersheeted) and the boat flat. Even with the rudder right down. Maybe i class a tiny bit as way to much but lee helm horrible. -------------
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