this is my first time here, i have a problem with that my A class boat that ive just bought in that it has too much weather helm and also tends to sail with the bow down (meaning i loose rudder control because of bow diving).
i would Appreciate any advice on how to correct these problems.
sounds like it could be fixed with a rig-redesign… little bit shorter aspect maybe… (that is to solve the nose diving) and either cut so SA out of the mainsail, or add some to the jib… (for the weather helm)
the other thing you could do, is just move the rudder back, and the keel forward! lol.
Just a thought - Almost sounds like you were sailing overpowered in too much wind…?? A’s often have a couple of sails or rigs for different windspeeds, especially smaller sails for higher winds speeds. If you were overpowered your boat would behave just as you described. Please ignore me if this was not the case.
Nose diving (off the wind) is another matter, and indicates you have (way!) too much sail hoisted for the conditions. An over-pressed (and well-designed) “A” will usually start to surf rather than nose-dive. Bulb cant is an issue here, and if you regularly sail in heavy weather you’ll need to tip your bulb up some:
i have just started R/C Sailing with a club in Tasmania Australia, which is nearly all “A” Class boats.
all the research i have done into “A” class boats ends up leading to you (your a Legend, the Guru of “A” class), love the Sword maybe one day i will invest in one.
Hope i haven’t em-barest you, i will try your suggestions with the twist in both the main and jib.
i just finished putting a topping lift on the jib boom and will let a bit more Vang of the main boom.
Just a thought, but does the boat sit level in th water? If she sits a bit bow down you could move the keel aft a little. This would help with both the rig balance and keeping the nose up?
BTW do you sail with kiwi Jack?
Thank for your reply, the boat looks to sit level in the water.
(photo of the red boat on previous post) i did have a look at your web site though and noticed that the mast on the 12 looks to be back from the front of the keel, and on my “A” the mast is in-line with the front of the keel.
is this the way of design or should my mast be More aft.
i sail with the North West Radio Yacht Club Tasmania don’t know of Kiwi Jack.
Thanks Again For Your Reply.
My first troubles i had with the boat were that i kept loosing my helm,
at first i thought it may have been radio interference, so i changed the crystals that didn’t help.
so i then replaced the rudder servo thinking that the gears may have been slipping.
when i put a little pressure on the rudder i found little resistance from the servo.
i also moved the tack further along the jib boom as recommended by a club member, but by doing all these things i still have weather helm and some bow diving which i believe to be the reason i loose helm at times whether it is because of the boat being unbalanced because of sail trim (i have little experience in sail trim) or the mast position, I’m experimenting with different changes.
hope to get it right in the end , i guess the more i play the more ill learn…
to answer your question in regards to wind speed it was about 15 knots using a rig maybe you can advise me what wind strength i should be changing to a B rig
John - As I first thought, it sounds like you were sailing in much too much wind for the A rig. As Lester suggests - a B rig or even C rig sounds like the call in that much wind (water conditions dependent).
Try sailing your boat in lighter winds (under 10 knots as Lester says) and you should be able to see how she handles and get some sail tuning done without the rudder wagging in the air…!!
Good luck and let us know how she goes in lighter wind.
Also, if she didn’t come with a B rig try getting one from your local club members or consider buying/building a new one. Even just using a smaller mainsail will help. I know Tasmania is a very windy spot so you might well use it more often than not.
Maybe you should find out who designed the boat, give them your feedback and ask for advise. It s possible they may know the boats characteristics better than anyone and be familiar with the “problem” you have had and know the easiest way to fix.
thank you for your suggestions, i have sailed in lighter winds with the A rig with a much better response.
i went to your web site Lester and tuned the sails to your general guide and with playing around with sail twist made big improvements in performance of boat speed and helm balance.
i will continue to experiment with tuning and twisting and hope to get it right on race day.
i am looking into getting a smaller rig and sails for those windier days, so far with my research i have found a few different configurations with rigs, carbon mast and booms, seems the carbon fiber mast is a bit stiffer than the aluminum i have now.
also i have seen i think it is called a Radial jib boom (pivots at the fore stay) any suggestions on which way to go as im starting from scratch with the new B rig.
Yes, just a bit (grin)… It makes a huge difference to the jibstay tension you can achieve, and holding head shape at the top of the wind range. But if you change to a c/f mast, move carefully. Your existing mainsail probably will have too much luff curve and when set on the c/f mast will push too much fullness into the mid-sail. Your existing jib will probably have too much luff allowance and when set on a c/f mast will yield too little fullness mid-sail…
also i have seen i think it is called a Radial jib boom (pivots at the fore stay) any suggestions on which way to go
The radial fitting offers an advantage (some say theoretically but not practically) in pointing ability and goosewinging on the run. But getting a friction-free swivel action for light airs is more or less impossible… I would suggest you retain what you currently have until you are able to gauge the pros and cons after some experience.