[Rhodes22-list] Curved Rudder | 84 Rhodes 22

[Chris on LBI]

Roger,

I don't have a sense for how much I moved the rudder blade on my two 
trials. I was just hoping that some change would be noticeable. I'll pay 
more attention next season, and, next time I have a chance, I'll try to 
measure the difference between the "full down haul" position and the 
vertical position. I'll also look at the mechanical stop to get a sense 
for how a shim might be implemented. But for now, I think just using the 
tension between the down-haul and the up-haul will be best for 
experimenting so that I can convince myself that helm behavior really 
does change.

On the two days that I experimented, I was intentionally keeping the 
heel angle minimal, attempting to keep it flat. The winds were around 10 
kts. I had the 130 genoa unfurled to the upper shrouds. So the luff of 
the headsail was not shaped well due to the sail furled on the headstay.

On many days, we find ourselves sailing in 18 to 20 kts. We tend to be 
timid about heeling too much and generally either fall off to a more 
comfortable (flatter) reach or reduce sail. I've never really 
experienced the transition to weather helm due to heeling - even when we 
are heeled past our comfort angle. We probably head up before heeling 
sufficiently to cause the hull shape to induce weather helm.

Chris



On 11/29/2022 2:55 PM, ROGER PIHLAJA wrote:
> Chris,
>
> After reading your post, I went out and looked my boat’s rudder.  On my R-22, the rudder blade pivots until it comes up against the underside of the rudder head.  On my boat, the leading edge of the rudder blade makes a straight line with the leading edge of the rudder head when the rudder blade is all the way down against this positive mechanical stop.  However, there are several manufacturing tolerances that can affect this geometry.  The exact size and shape of the rudder head and rudder blade relative to the location of the rudder blade’s pivot are critical.  If your rudder blade pivots too far forward, probably the easiest way to fix it will be to install a shim in between the bottom of the rudder head and the top of the rudder blade.
>
> I know from experience; that, pivoting the rudder blade up tends to increase weather helm.  But, in my experience, the helm is not that sensitive to this adjustment, especially when the rudder blade is nearly fully down.  How much did you have to move the rudder blade in order to get rid of your lee helm?
>
> By the way, what was your angle of heel when you were doing your tacking angle experiment?  As you may know, the wetted surface area of the R-22 hull becomes very asymmetric as the hull heels over.  The asymmetry tends to produce weather helm, becoming more pronounced as the angle of heel increases.  You may find your boat has lee helm when sailed flat, transitioning to neutral helm, and then weather helm as you heel over.  Before you modify your rudder, be certain you are not introducing heavy weather helm when the boat’s rail is in the water.
>
> Roger Pihlaja
> S/V Dynamic Equilibrium
>
> Sent from my iPhone
>> On Nov 29, 2022, at 1:13 PM, jpd9668 at gmail.com wrote:
>>
>> Chris,
>> Yours is much different than my experience. Until Stan instructed me how to use the downhaul on the rudder, I had severe lee helm. Once I pulled the downhaul tight my helm has been balanced ever since. If you're getting 95 deg. or less on point, that's pretty good. Do you have roller furling jib?
>>
>> Joe Dempsey
>> S/V Respite
>> Deltaville, VA
>>
>> -----Original Message-----
>> From: Rhodes22-list <rhodes22-list-bounces at rhodes22.org> On Behalf Of Chris on LBI
>> Sent: Tuesday, November 29, 2022 11:37 AM
>> To: The Rhodes 22 Email List <rhodes22-list at rhodes22.org>
>> Subject: Re: [Rhodes22-list] Curved Rudder | 84 Rhodes 22
>>
>> It is so interesting that to me that this topic just came up. I've been thinking about posting some late-season observations about my Rhodes that are closely related to this thread.
>>
>> After years of being frustrated with what I consider to be excessive lee helm, toward the end of this past season I noticed that the forward edge of my rudder was not vertical. It is much like the white rudder shown in Bob's photo. It kicks forward a little. In an attempt to rectify this, I changed how I was using the rudder down-haul. Rather than pull it tight, I eased off a bit allowing me to use the up-haul to make the leading edge of the rudder close to vertical.
>>
>> I only had the opportunity to try this twice before we had to take the boat out for the season, but in both outings, I was able to much more easily balance the helm and was able to tack very close to 90 degrees (something that eluded me on this boat since we purchased her). Attached is a diagram showing my track as I tested my ability to tack while sailing as close to the wind as I could. As you can see, the tacks were about 95 degrees. In the past I was generally closer to 110 degrees, so I consider this a great improvement.
>>
>> Also, prior to trying this adjustment with the rudder, we frequently had difficulty bringing the bow through the wind; we had to be very precise with our timing of releasing sheets. I did not have the opportunity to test the change in high wind conditions, but she seemed to be much more responsive to a turn to windward.
>>
>> I'll continue to experiment next year and spend more time working on a way to be sure that the leading edge of the rudder is truly vertical.
>>
>> Chris
>>
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