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rudder question


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I'm new to sailing (i've recently bought a prindle 15) so i'm still figuring out what's what. When I'm sailing the rudders are always pushing very hard in one director or another - it takes alot of effort to keep them in the middle and the boat going in a straight line. Is this normal? I've checked the rudders and they appear lined up to me, but i'm wondering if this is caused by rudders not lined up or bad sail trim?

Cheers,

Michael

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sounds like the rudders are raked backwards; the tips at the bottom too far back. This massively increases the amount of force required to steer or keep a straight line.

Depending on the rudder box design, you might be able to 'adjust' the pivot point, or where the blade hits the box at the forward edge. By adjust I mean attack with a power tool & then fix-up with fibreglass.

A rough guide is to sight through the pintle holes; the steering axis. You should see the front edge of the lower rudder tip. If it's 20mm or more further aft, then definitely they are raked too far back.

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Just checked a random photo of a Prindle15:

15082008673.jpg

Looks like they have a substantial cut-away on the leading edge, and when swung into place the rear edge is vertical.

Photoshopped pic below: steering axis is black line. Leading edge is parrallel and about 30mm in front of this:

[ATTACH=CONFIG]689[/ATTACH]

post-5814-13778265593353_thumb.jpg

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Thanks for your help and advice tony. I'll check it out on my boat tomorrow and see if that's the problem.

I wonder if perhaps i'm not positioning myself correctly on the boat and sitting too close to the bow, which would rake the rudders up due to the boat's angle? I'll try adjusting my position forwards/backwards as well to see if that helps.

Cheers,

Michael

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there's 2 separate issues:

1/ the amount of force required to steer, due to rudder rake. Possible solution described above.

2/ using your body-weight to make the boat turn

When to boat's underway and going upwind, you want to sit forwards and generate weather helm, as that rudder force contributes to lift to windwards. This feel like a gentle pull on the tiller extension, or if it's there's too much force to hang onto, see 1 above.

Going slowly, say coming out of a tack, if you sit forwards the boat may round up into the wind and go into irons. It will do this no matter how you try and steer with the rudders. In that instance, it's best to stay back near the rear beam until the boat has fully turned, got wind in the sails and is underway before moving forwards.

Basically; sit forwards to make the boat turn head to wind. Sit near the back to help the boat bear away from the wind.

Good luck!

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Thanks again Tony. I took the boat out yesterday, and this time i was paying attention to my position on the boat, which really helped - I wasn't struggling with the rudders this time.

I had my first capsize yesterday too - I wasn't able to right the boat myself but luckily a couple of guys on a tinnie helped me out :) I later worked out that I should release the line if i'm about to go over which saves me. I've got much to learn, but what a fun sport this is!

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sounds like you need to find a club that sails cats so that you're i) with 'friends' and ii) near rescue craft.

Capsize recovery is a bit of an art with cats and is worth working on, particularly if you're going out alone. Another thing to consider is buying a waterproof, handheld vhf marine radio they're really useful and you can then get in contact with the local rescue people. An EPIRB would also be a good idea if you really want to go out alone. Sailing on reservoirs is also a good idea as, whatever the wind direction you'll end up on a shore. Never leave the boat unless you are only a couple of strokes away from the shore.

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Thanks for your advice jimbo. Yep i'm planning on joining a club in a few months - i'll be moving house then but don't know exactly where or what clubs will be close by.

I'm going to invest in a righting bag/bucket or righting pole - until then I won't be taking the boat out too far from shore. They seem expensive though (including the postage from USA) - I reckon I could make a righting bag with a couple of $15 canvas buckets from BCF or a camping store and save some $. I'll also look at getting a vhf radio, although I do take my mobile out (with a waterproof cover) so i'm pretty safe there i think

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somewhere, I think it was on sailing anarchy someone put up picks of a righting pole, used by a guy with no legs. basically it was a windsurfer type pole hiinged at the dolphin striker and laying flat underneath the tramp. go over, put the pole up and once you've got the boat on its side you just hang onto the pole.

righting is a knack, might be worth putting a post up about it. darcy will have the tricks but I've found standing on the back of a hull puts the bows in the air and they then get some wind. make sure you uncleat the main first though.

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ahh yep, I did see the pictures of the home made righting pole. It's a great idea and looks fairly straightforward to make. I've just ordered a righting bag from a Hobie store in Mornington for just under $100 inc. postage, I think that just the bag will be fine for me as i'm sailing a 15 ft Prindle. When the bag arrives i'll run through some practice drills - I better do this now before the water gets too cold! I'll try your trick about standing on the back to get some air under the sails, thanks

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  • 1 month later...

To lift a hull on a cat, sailing on a reach is recommended. At first, you tend to stay close to windward, because windward 'feels' safe (because steering to windward kills the speed, doesn't it). You bear off more and more until you chicken out, and tend to steer (abruptly) to windward when it gets too hairy. However, abruptly steering to windward will increase heel of the boat; the mast is leaning over to one side, and you are abruptly steering the platform in the opposite direction(!) After some time you will learn that sailing on a true reach (with a somewhat loose main sheet), or even on a slight downwind reach (past the point of maximum sideways wind power) works even better; you can bear off to go downwind and the boat will straighten up instantly. Then, you simply stop caring as you got the hang of things anyway and simply do it. Stick with what you're comfortable with, or have someone take you for a ride on a 2 up cat while you skipper and he/she does the main sheet for you. Go with someone you trust and has the patience to explain and demonstrate, not to impress you. Alternatively, start from a downwind run and harden up until you are on a reach and fly a hull that way; when it gets too hairy, fall back to downwind. You'll find that you are far less likely to capsize. Still learning myself; good fun.

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Thanks for your post H. That makes sense about steering abruptly to windward will increase the heel of the boat - i didn't think about that. Next time I go out i'll try as you suggest and bear off downwind instead. I've been to chicken to take the boat out recently - it's been too bloody cold in Melbourne lately :-s I've bought a ronstan skiff suit, so hopefully soon I'll get the balls to go out and try it out.

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Alternatively, when learning to fly I'd suggest going close-hauled upwind in a light-moderate steady breeze.

Compared with doing it on a reach, upwind is slower, there is no risk of cartwheeling, and the lifting force is stronger and more easily controlled. Sorry H, if you're on a reach with the main loose, hull flying, and suddenly bear off in a gust, you're likely to nosedive and cartwheel. I can see that going from a reach to a run would remove the sidewards force, but it instead transfers to nosediving force. Going from closehauled to windward does not present this risk and is much easier to control.

If you start off sailing both hulls flat, sheet in hard, then gradually bear off, the hull will lift once the sails are full of wind. Keep an eye on your tell-tales and don't bear off too far.

You can learn to keep the boat balanced by bearing off more to lift the hull more (as there is more wind in the sail), or bring it back down by rounding up to windward (less wind in the sail). The centrifugal force of turning is insignificant compared with the force of the wind on the sail.

Once you've got a feel for the steering, then get the hull flying and practice sailing a straight line, and use only the mainsheet to keep the boat balanced. As peak gusts hit the hull will lift, so ease the mainsheet to compensate. When the gust has passed and the hull comes down, pull the mainsheet back in.

The advantage of sheeting in hard, is that the centre of effort will be quite high up the sail, so when you ease the sheet both the wind is let out and this centre of effort is dropped lower, reducing the overturning force.

Ideally you will keep the mainsheet in hard most of the time, with traveller set at different distances from centre depending on wind strength. As gusts hit, the "fast handling technique" (see Bethwaite's book "Higher Performance Sailing") is to ease the sheet a little and steer a little; a nice combination of both. Generally cats don't turn well and loose speed with steering effort, so most of your effort goes into working the mainsheet.

In light winds, you might need to sit in the middle of the boat, legs on the leeward side under the vang, and wait for gusts to lift you up.

Sailing Melbourne at this time of year, I'd be layering up with long-sleeved rashy, the skiff suit, a spring suit over the top of it, then a wool jumper, then the spray jacket, gloves, wetsuit boots and maybe a diving hood. Trouble is when you're dressed like the Michelin Man it gets hard to move!

Good luck with it

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Yeah, what Tony says. :-)

I've been doing exactly what Tony said. Then I tipped my cat a few times. Then I asked someone ('should I bear off or harden up when out of control?'). If you don't have that look on your face like 'trust me, I know what I am doing; I'm a professional' after a capsize, people will gladly point out what went wrong. Best is to not ask questions. I guess both will do the trick, but reading Tony's reply, I think he is a tad more right than I am (read: 'I was wrong'). Have fun. Be scared. I know I am.

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Good onya H, great attitude!

When watching people new to cat sailing, often I see the mainsheet too loose, so the sail is twisted and de-powered. When I take people for joy rides and hand them the tiller, they most often are far too radical and swerve all over the place.

This is understandable, given that in one hand you're pulling the mainsheet with all the strength you can muster, while in the other hand the tiller responds to the lightest, fingertip steering. I guess it's natural to expect to use even strength with both hands.

Good to read what obstacles you guys come across, what approaches you try, and to think about it all. I've been thinking about spending $1000 attending a YachtingNSW Dinghy Instructors course (they don't know what cats are), and this thread has helped inspire me to go for it. Cheers

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It depends on the type of cat that you sail if you even want to fly a hull.

A cat like a Maricat is much slower when flying a hull high out of the water...........don't know about Prindles.

A Maricat likes to be sailed fairly flat with the windward hull just skimming the surface. Too far up and the hull digs in and the boat goes side ways.

Bearing away from an over powered reach is not a good idea, unless you like swimming !

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