Weather helm

[Roland of Macatawa]

Bruce,

Yes, my rudder is positioned to be raked forward at the bottom.
The straight portion of the leading edge runs parallel to a line through the canted rudder/tiller steering axis,
and about 1+1/2 inches forward of that axis.
That pivot axis is canted, of course, because the transom is.
The 'chord' of the flat SS plate rudder is 12 inches.
So, ~1+1/2 inches is forward of the axis, and ~10+1/2 inches aft of the axis.

I do not have any mechanism to continuously adjust the amount of rake.
Would like to experiment, so may have to make something.

Haven't really been displeased with the rudder, yet I would like to optimize it.

Regards, Roland

[Jim in TC]

Hi Bruce,

Amazing craftsmanship, you are very talented. I'm afraid that may be beyond what I would like to tackle and have looked at the two replacement rudders offered by Rudder Craft, could you please share your insight with us on the pros and cons of each of them:

Com-Pac Sun Cat High Performance Foiled Replacement Rudder Blade ($375)
https://store.ruddercraft.com/index.php?route=product/product&path=181_29&product_id=135

Com-Pac SunCat High Performance Kick Up Rudder Assembly ($599)
https://store.ruddercraft.com/index.php?route=product/product&path=181_29&product_id=136

Just now dipping into this conversation...
My SunCat came with an after market rudder from IdaSailor that looks very much like the ruddercraft assembly. The PO was nervous about sufficient room to swing the tiller within the "slot" made for that in the transom, so had it set up to run the tiller over top of the transom. This was one of the (several) mods that I expected to change back to "stock" but found it comfortable enough seated and clearly advantageous standing, which I like from time to time. And by blocking off the back side I have a little storage area in a really handy spot...

I am pretty sure there were some modifications to the assembly to make it easier to pull up from the cockpit but can't really look until the boat is our from under the tarps. I can't compare it to a stock rudder, but the tiller is a beauty and it seems like a very durable piece of work that functions great.

[Andre]

Regarding helm balance, raked rudder, and reefing  ....

I have 2 reefs on both my PC and HC sails.  I've sailed my PC with the 2nd reef in many times with winds in the 25 range.  The 2nd reef greatly reduces weather helm to the point that it's almost neutral.  This is with the CB fully down. I have only used the 2nd reef once on my HC so it's difficult to judge plus there's less feedback with the wheel.

Anyway, the reason I'm saying all this is that with a non-adjustable raked rudder (which Bruce alluded to) and additional reef points one may find themselves with lee rather than weather helm.  Just something to keep in mind.

Andre

[Roland of Macatawa]

Excellent comment, Andre.

Yes, reefing the sail, like moving the sail forward by raking the mast forward, will reduce weather helm.
And possibly too much, inducing a lee helm.

Regards, Roland

[Bub]

I did go out last week in 12-15 kts and sailed awhile on all points of sail with the rudder raked forward. Then dropped it to the gravity induced vertical position and repeated the process.

I think the helm felt slightly better raked, but adjusting the weather helm by playing with the CB was more than adequate, easy to modulate incrementally, and safer than hanging off the stern looking away from the heading while loosening the friction bolt.

So I'm going vertical unless some problem arises later in the season..

[Bob23]

As an early contributor to this thread, I've been following with interest. This year before launching my 23, I plan to shift the sail plan aft just a tad to introduce some weather helm back in to the boat. A neutral helm is not only dangerous, but annoying too as the boat seems to wander like a drunken sailor on leave! Of course this means disassembling the CDI roller furler to expose the forestay turnbuckle but this should be inspected every few years anyway so no problem.
  I also have the option of tweaking the angle of the rudder a bit here and there so if the sail plan shift doesn't work, the rudder blade adjustment will!
  Fair winds to you all!! Here in NJ, we're just getting ready to uncover our boats so the excitement is building! Cheers!!

[bruce]

Thanks for the update, Bub. I was never a big fan of tightening the pivot bolt to hold the rudder down either!

Jim, thanks for your input on the Rudder Craft system. It is the same as IdaSailor, name change, I don't recall the details. Interesting that it's mounted so the tiller comes over the coaming. If you get a chance, when you get back to your boat a photo or two would be fun to see. I've heard the "slot" called the horn, don't know of its standing in official boat nomenclature.

+1 to Bob. We're beginning to see signs of spring!

[Jim in TC]

If you get a chance, when you get back to your boat a photo or two would be fun to see. I've heard the "slot" called the horn, don't know of its standing in official boat nomenclature.

I have a few pix from last year that show the tiller position, which if my experience with posting photos remains true to form will appear in a succession of posts...none of these are set up to illustrate the modifications that I think were added to assist in raising the rudder from the cockpit, which I can post later if there is interest. I think the proper nautical term is "slot thingee."

[bruce]

Thanks, Jim. Looks great. With the rudder pivot at this height, it doesn't look like they could have gotten the tiller through the transom. I see your cuddy, very handy.

I for one would be interested in more photos, if you get the chance.

[Jim in TC]

Thanks, Jim. Looks great. With the rudder pivot at this height, it doesn't look like they could have gotten the tiller through the transom. I see your cuddy, very handy.

I for one would be interested in more photos, if you get the chance.

When the original owner ordered the rudder, she had it set up for that height (I do not believe the gudgeons were changed as part of the project). Once the snow melts back (may be some time, considering current depth) I will get some photos that show the rudder more effectively, and illustrate mods made to the lifting system.

[Roland of Macatawa]

In this older CPYOA thread: http://cpyoa.geekworkshosting.com/forum/index.php?topic=6997.0

Found a photograph of the IdaSailor/Ruddercraft replacement blade on a CP-19.
RudderCraft has told me that they recommend the same rudder blade for both the SunCats and the CP-19.
Note that the rudder blade's leading edge is forward of the tiller/rudder steering axis, by about 15%.

Note also the comment of the author, skip1930, on the effect of the rake of the rudder upon weather helm.


Re: CP 16 RUDDER Questions
« Reply #6 on: 2013-12-08, 18:45:47 »

The CP-19 is fitted with the 'first' generation of the IdaSalor rudder which is not fitted with any lift rods or hold down 'detents'.
Just loosen the original jam bar that pinches the cast aluminum head onto the rudder and pull up the rudder with a line, and dog the line down.

The rudder even though it sits on bronze shoulder bushings still hangs down below the keel [+6mm] by about a 1/2 inch.
Being tired of pushing the rudder blade back down after the seaweed popped it up there is now a drilled hole and a shear bolt, later just a pin keeping it down.

It is noteworthy that these rudders be pushed 'hard forward' giving a bit of balance feel to the tiller. This rudder's leading edge is under the hull.

skip.

[Catawampus]

I have the factory rudder blade on my 2002 Sun Cat. I pin the blade all the way down (slightly forward of vertical) aligning the holes in the rudder head with the hole in the blade. I use a nylon bolt with nylon thumb nut in case I run aground. Weather helm, in my experience, can be almost eliminated with adjustments to the centerboard angle/depth.

[Jim in TC]

Thanks, Jim. Looks great. With the rudder pivot at this height, it doesn't look like they could have gotten the tiller through the transom. I see your cuddy, very handy.

I for one would be interested in more photos, if you get the chance.

A few photos of our after-market Rudder Craft (formerly IdaSailor) now that the covers are off the boat (and nearly ready for this year's first launch). As you can see, the rudder runs a bit forward of the stern but I don't know if it really stays there under way. I will watch for that when out in our first good blow. I know it does not "ride up" very far, if at all. I am pretty sure, given that one of the fairleads is attached with hose clamps, that at least that line for raising the rudder was added by the PO. It does seem to need both lines to fully furl the rudder from the cockpit. You can also see the cover I put on the slot ("horn?") where the tiller would have passed through before this mod. Very handy place to stow stuff for quick retrieval!

Mehitabel remains in the driveway, so if there are images that you would like to see, I can accommodate at least until the weather warms a bit more reliably.

[bruce]

Thanks, Jim.

I see the rudder rakes forward, but that appears to be because they design the deployed blade to be parallel with the pintels. If the you like the performance of the rudder in this position, that's all that matters in my view.

There doesn't seem to be a provision to adjust the rake of the rudder for an application where the transom isn't plumb. I don't know how difficult it would be for them to offer an adjustable stop, or if one could be retrofitted without interfering with the function of their mechanism, but the versatility of the design is compromised without it, IMHO. One could, of course, shim the gudgeons to eliminate the rake. I believe the stock SC is plumb. I can't accept that because Rudder Craft's generic design causes the rudder to rake forward that that is evidence that the rudder should be raked.

I agree that the second line is an add on, the hose clamps may work but they're not very finished. The line is attached to the forward edge of the blade, that will create significant turbulence. Looking at the link Roland provided from Rudder Craft for their full SC assembly, I see extra lines in the first two photos have been added, different from yours and each other. In the first one especially, on the SC with the white hull, it appears to be securing the blade for travel. In the copy, they state that it is a single-line system. The other thing I note is that they say that now can provide the assembly so that it will pass through the horn. In the photos, the gas struts are attached right at the tiller, there is little or no square tube showing above the struts. A tight fit! On other boats (in the video below), at least some square tube is showing, up to a foot in some cases. Yours looks to be 6-8", well within the range Your gas struts are well above the horn, looks like they're using shorter struts on the new option.
https://store.ruddercraft.com/index.php?route=product/product&path=181_29&product_id=136

Looking at a Rudder Craft video, they talk about the technique to raise the blade, and that a continuous pull will not raise the blade fully. This would a be another reason a second line might be added.
https://www.youtube.com/watch?v=lk1XwXuAll0

Spring has been slow in coming for us as well. Maybe next week.

[Jim in TC]

Thanks, Bruce, for that video link. Once again you have just the right information! I will tinker with the raise/lower technique described, since I was always assuming that a steady pull was the correct way to raise it. It did occur to me to wonder about the need to retrofit something on a rudder pretty clearly meant to be raised and lowered.

True, the hose clamps are less than elegant. My attempts at drilling that surprisingly hard metal framework resulted in a couple broken bits, and I haven't been out to get a "next level" bit. Maybe I will find that the original single line will do the trick and I can simple remove the extra line. It would not be the first modification I have had (or wanted) to reverse...

I think it would be relatively easy to build in a "stop" if one wanted the rudder to settle at a different angle. So far I see no need (plus, I would need another of those "next level" bits to make it happen).