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PostPosted: Jan 26th, '18, 20:14 
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Hi Dustinoz

As a former Sabre 22 owner I found that the most common cause of weather helm was the swing rudder not being in the fully down position.

If you can get hold of a copy of the original brochure it shows a sketch of the side profile of the boat with the rudder position as designed.

When fully down it is angled forward of vertical so that some of the leading edge is forward of the turning axis. This gives a balancing effect taking load off the tiller so reducing weather helm.

The reason this is necessary is that the swing keel is located well forward (to give more clear space inside) of the centre of effort of the sails. So the relatively large and deep rudder has been designed to take the resulting higher sideways load. As long as the tiller force is balanced by the correct rudder position, I found the Sabre would sail very well.

The original design of the swing locking method was by simply tightening the wing nut on the pivot pin to get enough friction to keep it in place. If not tightened properly the rudder can easily swing back even just a few degrees causing a huge increase in weather helm. There are various ways to improve on this such as fitting a pull down rope.

Of course all the points mentioned above regarding sail shape and keel position are important but its worth checking for simple problems first.

Cheers Bruce


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PostPosted: Jan 26th, '18, 23:35 
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BruBarb99 wrote:
... I found that the most common cause of weather helm was the swing rudder not being in the fully down position...


A poorly balanced rudder does not cause weather helm; it simply makes the helm very heavy and makes a little bit of weather helm feel like far more.

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PostPosted: Jan 27th, '18, 07:59 
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zebedee wrote:
BruBarb99 wrote:
... I found that the most common cause of weather helm was the swing rudder not being in the fully down position...


A poorly balanced rudder does not cause weather helm; it simply makes the helm very heavy and makes a little bit of weather helm feel like far more.


I'd go one step further and suggest lifting the rudder out of the water if you want the quickest way to learn how to get rid of weather helm. ( in a controlled, safe enviroment where no lawyers are put at risk) . Perhaps a less extreme version of that would be to secure the rudder central via bungy chords and start playing with sail trim / boat heel / weight forward etc. For some of us, nothing teaches quicker than doing , and nothing teaches the difference between a heavy helm a d weather helm like stopping holding the tiller. I learnt this in my first mponr - we were drifting in a careel 18 and were passed by an rl 24. Not knowing the rl was a faster boat, we tried to analyze what he was doing different - his rudder was swung up horizontal! So we tried it, then quickly realised the trick was to keep the rudder straight and steer via sail trim / boat heel. It took another hour to catch / pass that rl but we learnt HEAPS during that time. Nb horizontal rudders can put huge forces on the transom / pintles etc - only do this in VERY light weather

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PostPosted: Jan 27th, '18, 09:11 
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zebedee wrote:
BruBarb99 wrote:
... I found that the most common cause of weather helm was the swing rudder not being in the fully down position...


A poorly balanced rudder does not cause weather helm; it simply makes the helm very heavy and makes a little bit of weather helm feel like far more.



I agree with that, but thinking about the centre of lateral resistance, surely a large rudder would equate to a large additional area of hull or keel at the stern which should bring the CLR somewhat aft.

Sort of goes to my pet theory that the I563 would be better balanced if the keel was extended aft to the transom rather than sharply rising a metre or so ahead of the transom.

Going back to the aircraft analogy, most older aircraft have balanced control surfaces (ie. portion of the rudder etc ahead of the hinge point) to reduce the force required on the controls. But they also have a trimming mechanism which effectively applies a bit of deflection of the control surfaces to make the aircraft feel stable and reduce control forces. This is necessary because every time an aircraft flies, it is slightly differently balanced to the previous flight. So the trim is effectively masking a slight imbalance.

Better as Dandy says to get the boat well balanced if possible before trying to cover up the imbalance.

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PostPosted: Jan 27th, '18, 10:03 
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A couple of links with visuals - and suggestions regarding weather and lee helm...

John Ellsworth

School of Sailing

Morgans Cloud

The trim tab on an aircraft doesn't get rid of the out-of-balance forces, it replaces the pressure the pilot must physically exert on the controls to keep the airplane’s attitude stable. Unless it's a major load imbalance, the trim tab's there to correct minor changes to the balance (4 pax instead of 2; added baggage) and correct trim relating to changes in power settings and attitude (eg. climbing at full power vs power off descent, or adding full flaps).

Good luck.


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PostPosted: Jan 27th, '18, 14:14 
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MurrayF wrote:
A couple of links with visuals - and suggestions regarding weather and lee helm...

John Ellsworth

School of Sailing

Morgans Cloud

The trim tab on an aircraft doesn't get rid of the out-of-balance forces, it replaces the pressure the pilot must physically exert on the controls to keep the airplane’s attitude stable. Unless it's a major load imbalance, the trim tab's there to correct minor changes to the balance (4 pax instead of 2; added baggage) and correct trim relating to changes in power settings and attitude (eg. climbing at full power vs power off descent, or adding full flaps).

Good luck.



I think that's what I said! :)

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PostPosted: Jan 27th, '18, 18:19 
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I took a while to compose that reply... and didn't see your 08:11 post Peter Y!

What he said... :)



For this message the author MurrayF has received thanks: Peter Yates (Jan 27th, '18, 19:07)
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PostPosted: Feb 3rd, '18, 18:06 
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Peter Yates wrote:
zebedee wrote:
BruBarb99 wrote:
... I found that the most common cause of weather helm was the swing rudder not being in the fully down position...


A poorly balanced rudder does not cause weather helm; it simply makes the helm very heavy and makes a little bit of weather helm feel like far more.



I agree with that, but thinking about the centre of lateral resistance, surely a large rudder would equate to a large additional area of hull or keel at the stern which should bring the CLR somewhat aft.

Sort of goes to my pet theory that the I563 would be better balanced if the keel was extended aft to the transom rather than sharply rising a metre or so ahead of the transom.

Going back to the aircraft analogy, most older aircraft have balanced control surfaces (ie. portion of the rudder etc ahead of the hinge point) to reduce the force required on the controls. But they also have a trimming mechanism which effectively applies a bit of deflection of the control surfaces to make the aircraft feel stable and reduce control forces. This is necessary because every time an aircraft flies, it is slightly differently balanced to the previous flight. So the trim is effectively masking a slight imbalance.

Better as Dandy says to get the boat well balanced if possible before trying to cover up the imbalance.


Peter, If you do a search on "weather helm" on Investigator 563.com, you will see a lot of discussion on the issue. My I563 Yara has perfect balance, but it also has a non-original drop rudder. I think the problem is that the original rudder design was too skinny.

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For this message the author IanB has received thanks: Peter Yates (Feb 3rd, '18, 18:23)
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