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Starboard rudder won't lock down
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Author:  Abraham Jones [ Sun Nov 11, 2012 9:39 pm ]
Post subject:  Starboard rudder won't lock down

The last time I went sailing the starboard rudder wouldn't lock down because the cam is over rotating. I checked the slider that sets rudder rake in the tiller arm and it hasn't slipped out of position. I tried taking it apart and resetting the cam. The rudder locked down but when it came up the cam over-rotated again.

The port rudder doesn't have this problem. The difference between the two is that the port rudder has the stock spring plunger and the other has a H16 plunger. Until recently I haven't had any trouble with the rudders. Will replacing the H16 plunger with the stock plunger fix this? Thanks,

Abraham

Image

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Author:  srm [ Mon Nov 12, 2012 4:31 am ]
Post subject:  Re: Starboard rudder won't lock down

Quote:
Will replacing the H16 plunger with the stock plunger fix this?


Would certainly seem like a logical starting point. I'd also replace the cam.

sm

Author:  Abraham Jones [ Mon Nov 12, 2012 9:21 pm ]
Post subject:  Re: Starboard rudder won't lock down

Quote:
I'd also replace the cam.


The cam looks good.

Is it the same as the H16 cam?

The plungers aren't that different. The H20 plunger has flat sides. The H16 plunger is hemispherical.

I'd like get people's thoughts on what is causing the cam to over rotate.

Thanks,

Author:  srm [ Tue Nov 13, 2012 4:38 am ]
Post subject:  Re: Starboard rudder won't lock down

The catalog lists different parts for the H14/16 vs. H17/18/20 cams, so I assume they're different. Anyway, if you're having issues, the first thing I would do would be to put in the correct parts. They may look similar, but sometimes small variations will make a big difference in the operation of mechanical parts, so best to start with fixing what you know is "wrong".

As for what else could be causing the over-rotation. From your pic, it looks like the cam is over-rotating in the "up" position. Is that correct (sorry, I don't have a rudder handy to recreate what you've got going on)? It looks like you should be able to rotate it back by hand. I'd check for worn out components, and any excess play in the cam (oversized pin hole). Also, if the spring tension is too light, it will allow the cam to push past the detent in the cam and over-rotate.

sm

Author:  mmiller [ Tue Nov 13, 2012 5:26 pm ]
Post subject:  Re: Starboard rudder won't lock down

The H 17/18 castings use a square shaft for the (square/rectangle) plunger to run up and down. The H 14/16 casting and plunger are round. They are not compatible I wouldn't think, so replacing the plunger with the correct fitting one will be your first step. If the cam has been replaced or the casting is worn or deformed at the point the cam exits the casting... it might rise up too high and be able to rotate out of the casting under the cam. Another issue is lubrication. You have to properly lubricate the plunger to cam surfaces.

New cam held with the factory pressed-in pin... new plunger.

Author:  Abraham Jones [ Wed Nov 14, 2012 8:49 pm ]
Post subject:  Re: Starboard rudder won't lock down

I'll replace the plunger with a H20 plunger.

I've been using the H16 plunger for a number of years. It puzzled me that it just recently stopped working.

I always try and put a small amount of lithium grease on the cams and plungers before a sailing trip. I learned that the hard way. When I was new to the boat I broke a bunch of rudder cams before an acquaintance suggested some lithium grease. A note to that effect in the assembly manual would've been helpful. I don't ever remember having to put grease on H16 cams. That's how I got the H16 plunger. I broke yet again, another cam at a regatta and the same acquaintance gave me a H16 plunger. I put it in and forgot about it until now.

What's the story with the factory pressed in pin for the cam? I recently replace the pin in the cam that over rotated. When I was messing with it I noticed that the old one had stripped. Should I send the casting in to get a factory pin for the cam? Thanks,

Author:  mmiller [ Thu Nov 15, 2012 4:04 pm ]
Post subject:  Re: Starboard rudder won't lock down

The pins are flared on both ends when installed. They don't have to be installed by the factory... just are the factory original part instead of the threaded (sister) screw type. Those are loose, wallow out the hole and can allow the cam to move vertically away from the plunger which could cause the plunger issue you experienced.

Author:  dray [ Tue Nov 20, 2012 11:01 pm ]
Post subject:  Re: Starboard rudder won't lock down

the problem is quite obvious from studying your pictures.
Lincoln, on your lucky penny hasn't learned to text you that there is a problem. He's looking right at the darn thing.

Actually Matt sounds right on. The only thing I could add is possibly add spring pressure with your adjustment screw so the plunger is tighter on the cam.
Does your rudder kick up when under load (like on a screaming reach)?
Or, is your tiller hard to pull up when raising your rudders?
This would be the spring pressure needing adjustment.

Lastly I sail in salt water and never grease my cam. it washes off when I rinse the boat down so why bother. Cams are more of a tell tail when something else is worn out like the hole oblonging in the rudder. That will screw up a cam fast.

Author:  Abraham Jones [ Sat Nov 24, 2012 9:11 pm ]
Post subject:  Re: Starboard rudder won't lock down

I did try to back out the screw that tensions the cam spring. It's frozen.

The tiller has always been easy to lift. Lifting it on the water, to clear sea weed for example, would invariable break a cam. Greasing the cams fixed that though.

I've never had any trouble with the rudders kicking up under sail. My Dad and I are big. Both of us are ~380lbs. When were both out on the wire the boat is moving. The dagger boards will hum as the boat surges with gusts? I tried wet sanding them and putting on a couple of coats of hull polish. I can't tell if it helped. I digress but why is the shape of the dagger boards different from the rudders? I'd expect the dagger boards to have an elliptical outline like the rudders.

Author:  MBounds [ Sun Nov 25, 2012 5:29 am ]
Post subject:  Re: Starboard rudder won't lock down

Abraham Jones wrote:
[W]hy is the shape of the dagger boards different from the rudders? I'd expect the dagger boards to have an elliptical outline like the rudders.
Probably the biggest reason is practical - when the boards are fully up, an elliptical board isn't stable in the trunk.

Boards with squared off ends are also much easier to make and less prone to damage.

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