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PostPosted: Sun Aug 22, 2010 3:13 pm 
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Joined: Thu Apr 24, 2008 3:58 am
Posts: 576
Location: Knoxville, TN
I was on the lake sailing my H14 in about 13 knots yesterday, sheeted in on a reach and just about to fly a hull when I heard a big "snap" and felt the tiller get light. The rudder had broken adjacent to the bottom of the transom. I'm sure I didn't hit an unerwater obstacle. I've heard of rudders breaking when a boat was "loaded up", although I'm not sure what that means. Can someone explain the physics of "loading up" the rudders and what makes a rudder break under these circumstances? Where is the stress coming from? Lateral resistance? Here's the pertinent information:

Boat - 1982 H14 Non-Turbo
Rudders - original white rudders, 28 years old
Wind - 13 knots
Crew - solo, 200 lbs
Weather helm - the other rudder, to weather, wouldn't lock down
Underwater Obstacles - None

Any ideas? Don't tell me I need to lose weight, that's not likely. Does age have anything to do with an old rudder getting brittle and more susceptible to breaking. I'm planning to replace my rudders with standard white nylon ones. I don't race the 14 so I don't want to spend bucks for EPOs (do they make them for the 14?)

Nest Question. The other rudder won't lock down even though the cam is in the proper position. The bar in the upper casting doesn't seem to catch the cam to turn it dowwnward when I push the tiller arm back. My boat is old and was built before Hobie started putting the cam stop plate in the casting. Any suggestions? When I order some new rudders (I'll replace them both) I'm going to order a new set of cams with the sister screws, but I'm not sure new cams are going to solve this problem. I'd appreciate your inputs.

Thanks,

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Mark Van Doren
Division 9 Chairman
H16 #112205 (Richard Petty Signature Edition)
H14T #47787
H20 #647 (sold)


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PostPosted: Mon Aug 23, 2010 11:16 am 
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Joined: Mon May 24, 2004 10:33 am
Posts: 418
Location: Clinton, Mississippi
Yes, it's the lateral resistance loading up the rudders....increases w/wind speed and weight on the boat. Since the 16s and 14s don't have daggers, their rudders carry a lot more load than the symetrical hull boats. It is very common for old, oxidized plastic rudders to break.....happens all the time just as you describe. More likely to occur as you fly a hull and the leeward rudder takes even more load. Even when they don't break, you can see them bend under load which leads to stalling and poorer performance than the EPOs and racing rudders. You should be fine rec sailing w/new plastic ones, though. The rudder blades are the same for most of the Hobies, but there are several hole patterns: http://www.hobiecat.com/support/tech/rudder.html

The hole for the pin in the cam may be wallowed, or there may be other hidden problems that you find during the redo. Check and correct as much of this as you can: viewtopic.php?f=18&t=467

With non-adjustable castings, your only real control over rake has to do with the location of the holes in the rudders. I don't believe new rudders come pre-drilled.

We were out here Saturday as well....unbelievable wind for August in this area! Almost makes up for the incredible heat!

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Jerome Vaughan
Hobie 16


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PostPosted: Mon Aug 23, 2010 4:01 pm 
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Joined: Thu Apr 24, 2008 3:58 am
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Location: Knoxville, TN
Jerome, Thanks.

Your explanation of the breakage seems spont on. I'm still vexed by the bar in the upper casting that passes over the top of the cam and won't engage it to make it rotate.

Shreveport Yacht Club's annual fall regatta, the Combeaux, will be Oct 23 and 24. For the first time in a while we'll probably have a H16 fleet and maybe a few 20s. I'll send you a NOR in a few days. I've been pushing Hobies here and it's gaining momentum. When's your next regatta in Jackson?

Mark

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Mark Van Doren
Division 9 Chairman
H16 #112205 (Richard Petty Signature Edition)
H14T #47787
H20 #647 (sold)


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PostPosted: Tue Aug 24, 2010 11:06 am 
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Joined: Mon May 24, 2004 10:33 am
Posts: 418
Location: Clinton, Mississippi
The rudder rake and cam-locking clearance are related dimensions that that depend of the hole pattern in the rudder. I'm betting something's amiss with your hole pattern. Do you know the history of this boat? People mix/match parts all the time, and you may have ended up with a rudder drilled for a different model boat and/or casting. Note that the recommended pattern is even different for boats of the same type, depending on whether or not the castings are adjustable. Besides all that, I believe most rudders are drilled free hand (and maybe not even by the dealer), so it would seem pretty easy to make a small mistake in the hole location that translates to a bigger rake/locking problem.

I'll pass along info on the Combeaux, but if the OSYC holds their Shearwater Regatta as scheduled, some of us will likely go there instead. (http://www.osyc.com/index.php?module=Co ... iew&pid=22) I enjoyed all of my past trips to SYC immensely, but OSYC is like a home away from home, and I support them every chance I get after all they've been through with Katrina, the oil spill, etc.

Our cat club doesn't host events, but some of us willl be doing Jackson Yacht Club's Hospitality Regatta (http://www.jacksonyachtclub.com/club/sc ... rp=0&NS=RR) the weekend of October 9 & 10. If some of y'all want to come, you're welcome to use our beach to launch, store, etc. for the weekend!

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Jerome Vaughan
Hobie 16


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PostPosted: Tue Aug 24, 2010 1:14 pm 
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Joined: Mon Sep 20, 2004 12:36 pm
Posts: 758
Location: Tri-Cities, WA
Here is a good link for all sorts of Hobie stuff, including a template for drilling (checking) rudder hole placement http://www.hobiecat.com/support/tech/sailboat.html :wink:


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