weatherhelm

Discussion in 'Sailboats' started by getango, Aug 8, 2005.

  1. getango
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    getango Junior Member

    I have an old McVey Falcon 16. I sailed it twice in the last 2 years. Everytime I went out, the rudder broke due to severe weatherhelm. I am still a beginner sailor and I have tried in vain adjusting the mast angle to eliminate this problem. Can someone please help!
     
  2. gonzo
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    gonzo Senior Member

    Rudders shouldn't break regardless or weather helm. You need to fix a structural problem. Can you describe what you mean by severe weather helm?
     
  3. getango
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    getango Junior Member

    Naturally, I expect some weather helm, but this is so bad that I have to hold the tiller against my stomach and even that's not enough. The pressure is incredible even with main fully released. I'm not sure what you mean by a structural problem. After the original wooden rudder broke, I bought a fiberglass rudder approximately the same size, but that one crushed under the hinges from the pressure. Am I trying to sail the boat in too much wind? I estimate both times I tried to sail it, wind speed was about 10 to 12 knots.
    I also have an 18' catamaran that I sail regularly, oh what a difference, I barely have to do anything with the rudders. Thanks for your help.
     
  4. gonzo
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    gonzo Senior Member

    Is the mast as far forward as possible?
     
  5. getango
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    getango Junior Member

    Yes it is, but I managed to get just a little bit more out of it. The main stays were a bit loose and the turnbuckle on the forestay was in all the way, so I modified it slightly to get about .75" more. I did not get a chance to try it out this way yet. Do you think this much will help any?
    I have been trying to find information on this boat on the internet, there isn't much out there, but the few pictures I saw looked like the jibs were bigger than mine. Yesterday I talked with a sailmaker who told me a bigger jib will make the problem worse because the boat will heel over more. What do you think?
     
  6. gonzo
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    gonzo Senior Member

    A bigger jib is a usual way of balancing weather helm. It will move the sails' center of effort forward
     
  7. getango
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    getango Junior Member

    If I want to have a new jib made, what area should it have compared to the main sail? Is there a ratio between them? Does it depend on mast location, LOA and beam? I see some boats where the mast is placed further aft and some forward. Thanks.

    GT
     
  8. getango
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    getango Junior Member

  9. asathor
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    asathor Senior Member

    You can get a serviceable bigger jib for $50 from Bacon & Associates - don't spend until you have the problem solved.
     
  10. usa2
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    usa2 Senior Member

    If a sailmaker turns down a client by saying there is an alternative to a solution than buying a new sail than there almost certainly is one.
     
  11. getango
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    getango Junior Member

    I have been doing a lot of research on boat design in the last few days. I am amazed at the wealth of information available. Now I know for sure that the jib is too small. I took measurements of the main sail and the jib, 81 sq. ft. and 27.5 sq. ft. This results in only 25% of total sail area. Many threads here and websites talk about a 60 to 40 ratio. If I use this ratio to calculate the total sail area this boat should have,(assuming that the main sail is the original), then it should be 135 sq. ft. which results in a jib area of 54 sq. ft. I know there are more precise ways to figure out what the sail area should be according to hull displacement, but I am taking a shortcut.
    With the numbers above, it looks like my boat should have a genoa instead. It will overlap the main by at least 3.5 ft., but I am not too comfortable with my results. Any comments?

    Thanks,

    GT
     
  12. gggGuest
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    gggGuest ...

    Overlap on the jib won't do much to redress balance because you're putting the extra area right on the point of balance. The ratio between jib and mainsail is very fashion related. On the high performance dinghies I race 30% is typical. On the gaff cruisers I sail occasionally its much less, because themast is proportionally much further forward in the boat.

    Overlapping jibs aren't very efficient when you treat the rigas am aerodynamic whole, which is why you don't see them on the more open rule race boats. They do enable manufacturers to put more sail area on small spars though.

    Now this may be a silly question, but are you sailing the boat upright? Many boats have desperate weather helm when heeled but are fine sailed upright. Maybe you just need to reef sooner and/or play the mainsail (think fisherman and big fish).

    However failing that I would think a short bowsprit and the same jib would be far more likely to solve your problem than a big overlapping jib from the forestay.
     
  13. getango
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    getango Junior Member

    I cannot say how the boat sails upright, I really did not get a chance to sail it that long, but I would imagine that the problem would improve. Also, being a beginner sailor, reefing the main did not occur to me. I like the idea of a short bowsprit, but how about a jib that goes all the way up to the top of the mast, would that be more efficient than the overlapping setup?
     
  14. Gilbert
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    Gilbert Senior Member

    Hi gt,
    I looked up the Falcon in my Encyclopedia of Sailing and it lists the sail area of you boat at 137. So I would say you may be on the right track with the bigger jib idea. As to how the original sailplan was arranged I have no information. As to the bowsprit idea, if you can not see any evidence of one having been on the boat before it probably did not have one. If there is no evidence of having been a stay to the masthead then there probably wasn't one of those either and any sheave at the masthead was probably for the spinnaker.
    Sorry we don't seem to be able to help you more. Maybe try an internet search for class association or clubs which may be able to give you more information.
    Good luck,
    Gilbert
     

  15. John ilett
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    John ilett Senior Member

    Maybe it's not the rig balance but the foil balance relative to the steering axis. Eg if it's a swing down blade that is not fully down then the normal helm pressure would be exagerated. Is it really the correct rudder for the boat??
     
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