Possible design flaw in Tandem steering?

Not to make light of any of your problems, but most of us have been lucky to have no rudder problems to date with the TI, so replacement and adjustment of your rudder assemblies should fix the problems.

I was out yesterday in an AI with friends in my TI and encountered very, very rough conditions and winds varying from none to well over 30mph. Three miles from shore, we hit a top speed of 12.3mph and cut through the tops of many 4-7' sloppy wind waves, coming from two directions, with a few trying to double-up in height! We even had a waterspout form about 300' from us for a few seconds. One of the top 5 worst conditions I've EVER sailed in. The AI and TI came through with no, issues, no steering problems, no breakage. They performed flawlessly, as they should for all of us. I'd recommend everyone still having these rudder issues to call you dealer to have whatever is out of spec replaced and everything adjusted till it's as it should be.

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Hobie Island Sailing since 2006

I note that you are about 50% reefed! Glad that you are in the minority of having no rudder problems.
Do you find that the AMAs sometimes dislodge from the AMA arms while sailing in high waves? My bungees are stretched tight, but the arms sometimes pop out of the AMA holes.

Yep, that was a worry (among many others) in the sloppy waves. At times the ama got very noisy, but I've never had one come completely off. I'm glad I took the tramps off or they would have flipped it for sure!

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Hobie Island Sailing since 2006

Reconlon,

You need to resist the temptation of jumping waves and catching air

I have the same worries. The sound that it makes when the aka pops back in is kinda unsettling. Not sure if anyone tried using a limiting strap yet. The stock bungees seem to keeping the amas in place. But over time as they strech out, I'm not sure if they'll be able to remain effective. Looks to be another maintenance check...

cliffs2yak

Marc,

Bungee cord is a great idea. I tried it today in light wind conditions and it seems to work - will wait for stronger wind to be sure. I used an old slingshot cord and its pouch to cushion and secure the rudder down as shown below. Climb into rear section and unhook it before using the up/down line. Not a remote control but allows use of the T&S for shallow water and transportation with no adjustments - just hook it on or off. I look forward to windier days to optimize its tension. BTW it has the added benefit of slight stickiness so rudder stays in the direction you set it. I did not use any down rudder tension so it makes it easy to turn either way.

Pros:
1.low cost, $10 at Amazon http://www.amazon.com/Marksman-3330-Slingshot-Band-Replacement/dp/B000Q9F2US/ref=pd_bxgy_sg_img_b
2. time to put on and adjust tension - about 10 minutes
3. time to hook on and off before using up/down line - a few seconds
4. easy to turn either way, no down line tension needed
5. rudder stays where you put it

See below.

Bob

Kayaking Bob might be right. Only a select few of us have steering problems. Since Hobie says it's not a design issue I sure hope they don't balk at replacing my rudder assembly.

Considering what these boats cost we shouldn't have to hold them together with rubber bands, I mean bungy cords. (Has anyone tried to fix their rudder with duct tape yet? LOL

In the mean time I want to thank the two people who posted the bungy suggestion. It will keep me on the water while I wait for new parts.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

From feedback on the forums and through the Hobie Cat Company warranty department we have become aware of the various problems TI users have encountered with the rudder system. We take all such concerns seriously and apologize for the inconvenience and frustration that it has caused those who have experienced difficulties. The TI was thoroughly tested for more than a year before its release and these recent rudder issues have definitely caught us all by surprise. There can be subtle changes that occur between prototype pre-production and full scale mass production which can lead to unexpected outcomes. I and the engineering team at Hobie are working diligently to create lasting solutions to the problems with the TI rudder system. A member of the engineering team, or the Hobie Cat warrany department will post more information/solutions as they become available. Thank you all for your support of Hobie Cat Company.

Jim Czarnowski, Director of Engineering
and the Engineering Team

Hobie Cat Company

Thanks Jim. Look forward to hearing about Hobie's solutions to the steering issues.

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I'd rather be sailing,
Mark.

Bobco,

I like that solution, I might try that one also.

To summarize my experiences thus far:
I have been happy with the lock-down rudder solution I am currently using. It has proven (in my mind a number of things).

1) Locking the rudder down via down line - does increase tightness in steering, especially starboard.
Using lock down nut/bolt eases that stress and ease of steering is vastly improved.

2) The left/right lines (if too tight) also contribute to tightness in steering. I have also notice that the left/right lines are temperature sensitive. For example, in the am, the lines have some slack but in the afternoon when temp is 95 or hotter both get very tight. I do not know if this is cause the lines themselves are getting tight or it is because the kayak is expanding/contracting due to the temperature changes and where the lines inside the yak are being push slight further out or something. Does that make sense, anyone else notice this ?

3) Rudder locked down via nut/bolt eliminates the rudder pop-up issues, which of course happen if the rudder is not locked down super tight.

One redesign idea I have is this: The lock down line should run down backside of the rudder and attach to the back of the rudder vs in the drum as it does now. I think this would keep the rudder locked down and ease the amount of tension on the rudder at the same time. I probably need to create a drawing or something if this does not make sense.

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I'd rather be sailing,
Mark.

No time to 'tech' up my sketches, so thought I'd post the sketches instead. There are two separate devices, both of which use the simple 'snap-action' principles often used in micro-switches etc. Each has one moving part, the 'actuator', plus a stainless steel spring to provide the 'snap' action.

Fig 1. Rudder Lock

In it's initial state, the locking pin at one end of the actuator is retracted, so the other end, which has a 'ramp' is protruding into the rudder slot.

1. Down line is pulled, and as the rudder is almost fully in the rudder slot, it pushes against the ramp. This causes the actuator to 'snap' over, so that now the pin end is pushed (by the spring) against the rudder.

2. As the rudder fully enters the slot, the pin engages into a hole in the rudder. The rudder is now 'locked'.

3. However, as the pin has a hemispherical end, a sharp force against the rudder (such as running aground) will force the pin out, as it is held only by the force of the spring.

Fig 1:



Fig 2. Release Line Mechanism

This mechanism is installed inside the hull, not far aft of the rear hatch for easy accessibility. In this illustration, the rudder is down. A 'striker ball' has been fastened to the up line. To release the Rudder Lock:

1. As soon as the up line is pulled initially, the striker ball engages the slotted end of the actuator, pulling it forward, and thus the Rudder Lock Release Line, and in turn the actuator in the Rudder Lock. The Rudder Lock is now disengaged.

2. As the up line continues forward, the line slides out of the first 'arm' (A) of the actuator, which 'snaps' over, allowing the second 'arm' (B) to engage the up line via it's slot.

3. When the down line is pulled, arm B is pulled backwards by the up line as it returns, and 're-arms' the Release Line mechanism.

Fig 2:


Although my sketches look a bit 'complicated', the two mechanisms are quite simple really. To install them does not require removal of the up line etc. There is no constant tension required on the extra Release Line, so it will not affect rudder movement.

The Release Line is routed via a hole drilled in the top of the rudder housing, then through the up line hull opening:



In an ideal world, this would be produced by Hobie, as they have the engineers who can calculate the sizes/leverage of the actuators and spring strength etc, and the production facilities for the couple of parts required.

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Cheers, Max ● TI: the "Yella Terra" ● Website: www.MadYakker.com ● YouTube: madyakkermax

Thanks Jim. Like the others who have problems, I will anxiously wait for Hobie to sort this out, confident that they will. Appreciate your words.

Thanks Jim,

It's good to hear that Hobie realizes that the rudder has some problems.

I'm anxiously awaiting to hear the solution.

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Jerry D.
St. Johns, Florida
2010 TI
2008 AI

Thank you, Jim for that assurance. I wish we could learn what the visible differences are between the good rudders and those that don't work well. Just the same, I'm confident that Hobie will have a solution and look forward to it.

Having never seen a TI without my problem (I examined the TI rudders at my dealer so I can't see any difference with mine), I'm still wondering how the functioning TI rudders manage to stay in their sockets without any down line tension under very windy conditions. I'm guessing that the "tongue" part of the stationary part of the rudder must be more exaggerated (lip not worn down) and angled more inward (smaller socket) so it sits tighter in the groove on the movable rudder blade - or the groove is deeper. Obviously, there is some level of tongue and groove tightness that would fit securely enough to keep the rudder locked down.

My TI is tied to the dock in the water, so not easy to photograph right now, but next time it is on the trailer, I want to post a close-up (with ruler) of the tongue, gap and groove portions of the rudder lock mechanism so others can compare mine with the good rudders. If mine is worn or filed down and/or the gap is wider or the groove is quite shallow compared to the TI's that work well on this forum, then perhaps new buyers can pre-screen the TI's before purchase to avoid the bad ones.

In the meantime, I needed some way to go sailing safely. The fall is coming when the winds pick up and now I feel tentatively more confident that my temporary bungee solution will allow me to sail safely when the wind is strong and the water cold. Without the bungee, I feared that the needed tension on the right steering line due to the tension on the rudder down line (to keep it down) would result in a steering line break and I would have to paddle/pedal in or try to steer with my oar and in the process risk hypothermia/fatigue.

Waiting patiently for the next windy day to test/fine tune the bungee temporary fix.

Bob

I bought a 'white' nylon 3/16" diameter (#8) bolt...1 1/2" long (1 1/4" would also fit...but the store only had 1" and 1 1/2" bolts) . I didn't want to have to have a pliers/wrench along to replace the bolt so I bought a nylon thumbscrew rather than a nylon nut. While the TI was on the trailer...I pulled the rudder down as tightly as possible before drilling through the first rudder bolt hole so that the rudder would be as tight as possible in the rudder clip when the nylon bolt was installed. A 3/16" drill bit fits the bolt hole...so if Hobie does eventually provide a fix...I can simply reinstall the factory stainless bolt and nut.
I found that I could tighten the thumbscrew quite securely without it breaking, but still able to remove the bolt when I need to, to put the TI back on the trailer. The 3/16" diameter is small enough that I believe it will act correctly as a shear bolt but still thick enough to withstand the outward pull of the rudder when speed is up.

I am sure that I am going to pop the nylon bolt when I forget and run onto a beach at some
point. So I bought a spare bolt and thumbscrew and keep it in the 'gear bucket' along
with the spare rudder pin.

I thought about using a 'bungee' strap as shown on a couple of the threads...but that would mean a compression effect on the rudder running from the rear of the rudder blade to the front. Matt Miller has warned us about not putting to much warpage on rudder when in
the stow position (don't put both bungee cords across the rudder while in storage). So
I assumed that if the little bungee storage straps could permanently warp the rudder blade
that a tight strap holding the rudder down could also warp it.
So the trade-off is: 1) use a nylon bolt/no rudder warp but no easy drop back if the rudder
hits something; or 2) use a bungee strap which pops the rudder back down when hit but
with a possibility of permanently warping the rudder.

Excellent discussion going on. Who would have guessed that TI owners were the most innovative engineers on the water?
I already own a series of twist and stow Hobie kayaks, and the only problems which surfaced were on the new TI. Perhaps it is the angle of line pulls, or shallow grooves, or a larger rudder (causing more stress on lines and side pressure while sailing). Regardless, I anxiously await a complete Hobie re-analysis and near term fix.
Thanks.