Rudder questions

[tc53]

I have two questions/issues involving my DS 1 rudder. First, I am wondering what my best option would be for replacing the bolt that is currently inserted through the upper housing portion and the upper portion of the blade itself in order to keep the blade in its down position. Right now, I am just using a long SS bolt with washers on both sides and a butterfly nut (that is until the latter fell into the lake last weekend). Is there some sort of pin that would be quick to withdraw (and less awkward than a butterfly nut) when I want to kick the blade up (in beaching the boat, for example)?

Second, the very top portion of my rudder, where the tiller attaches, has developed a crack (see photos below). Any suggestions for the best way to repair this?

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[GreenLake]

First, I split this off, because I thought that it was not about the uphaul/downhaul issue, but perhaps deserved its own thread. But now, I'm not so sure. I thought your bolt with wingnut was the pivot, but it seems that you have a separate bold that acts as an arrester in the down position. (You don't give us an image of that lower part).

For improving that issue:

• Option one, see how to rig a downhaul line in the parallel thread.
• Option two, use something like a chopstick to hold the rudder down - that has a the chance of breaking if you hit ground.

Anything else, you risk ripping out your transom (or at least your gudgeons) if you run aground hard.

For the broken rudder head: A good option is to simply replace the whole thing. You can easily recreate the shape from marine plywood (I know, because I've done it - look for my older thread on rudder rebuild). You might not want to stop there, but might want to rebuild the blade as well, so as to give it a better foil shape.

Some other posts talk about fashioning a rudder head from metal. Might be an option if your tooling runs more that way.

I mean, you could grind off 1/8" on either side of the existing head, and re-build that by adding laminate, but it's almost more work, and the result is still a bit slapdash as a repair.

[jeadstx]

I cracked a rudder head as well a few years ago. I built a new rudder head using 3/16" aluminum plate with a mahogany core. It used the standard rudder blade, but allowed it to be raised higher out of the water for beaching the boat. The attached picture is a modification of my original design to make the rudder head a little lighter while retaining strength (original is a little heavy but very strong). Tim Webb made something similar, but with a few differences for raising the blade in shallow water (his design was light and strong). I used a mahogany core for attaching the pintles and sides, Tim used spacers for his bolts as I recall. My rudder head didn't require any machining, only a saw to cut the aluminum plate and core to shape and a drill. As I recall I spent about $75 for materials. I added uphaul and downhaul lines also.

Rudder Head Layout.jpg (224.29 KiB) Viewed 8041 times

John

[tc53]

In working on my old DS 1 rudder to try and get it to "kick up" fully, I noticed that the reason my will not kick up is that the top of the rudder blade, the semi-circle section housed within the rudder "head," contacts the bottom of the head section in a way that keeps the rudder blade from pivoting all of the way up. Mine gets maybe 25% of the way, then this head-blade contact keeps it from going any farther. I'm not explaining this very well. Here is a photo:

This shows the top of the rudder blade just about to contact the bottom of the "head" section of the rudder.

IMG_2799.jpg (13.39 KiB) Viewed 7788 times

Here's a side view of the rudder showing it as far up as it will pivot.

Rudder blade as far up as it can go, given the contact the blade is making with the head

IMG_2798.jpg (17.44 KiB) Viewed 7788 times

So, my question is should I modify the top of the rudder blade so it will clear the bottom of the rudder head? I was thinking so until I used a homemade "compass" to draw a pencil line of what would have to be taken off to keep the "arc" of the semi-circle a consistent distance from the pivot point (that pencil line begins right at the point that the blade is blocked from pivoting up any farther). This seemed too drastic a change to make in the blade:

The top section of the rudder blade, with my pencil line showing what would have to be removed.

IMG_2797.jpg (13.39 KiB) Viewed 7788 times

Or, should I try an modify the wooden bottom section of the rudder head to allow the top of the blade to pivot fully up. I'm not sure, though, how I would do this without taking the entire head section of the rudder apart. Or (another thought) am I wrong about all of this and is that as far as the blade is meant to pivot up (I have been assuming that it should pivot all of the way up to, essentially, a waterline position). Any suggestions?

[GreenLake]

I can't tell from the pictures whether the rudder is oriented the right way. If there's any difference in the two edges you want the more rounded one towards the front. If there is no difference, then try both orientations and see whether one of them allows for a better angle.

If it was correctly oriented:

Rather than surgery on an existing blade, I would suggest making a new one, especially if the profile on the existing rudder doesn't look like a teardrop, but instead is symmetric, or like a squashed and stretched hexagon.

It's really not as involved as it may appear. (See Building a rudder on this forum).

I built one with a matching rudder head, but there's no reason one couldn't retain the existing head.

[jeadstx]

That is the reason I built a new rudder head. The design I have posted above allows the stock blade to rotate out of the water for beaching in shallow areas. You will see on the drawing, the lift provided by the stock rudder head and the angle of rotation I can get from the new rudder head.

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John

[GreenLake]

Even the stock rudder that came with my boat (DS1) was able to rotate further than shown in the pictures, although not past about 90 degrees.

By class rules, the pivot is 1.5" above the design waterline, that leaves some part of the rudder projecting below the hull.

Another reason to replace the stock rudder is that it is heavy. The replacement I built floats, the stock rudder didn't. Weight at the transom is not a good thing.