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Have you done any "expedition" trips on the AI?
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Author:  Chekika [ Wed Jan 18, 2017 3:12 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Geesus! Strips of truck inner tubes! I can buy these EPDM rubber straps for next to nothing at multiple places. I don't normally have truck tire inner tubes lying around. I'm sticking with the rubber straps. If they only last 2 yrs fine, easy to replace.

Thanks for your comments, Pete.

Keith

Author:  Chekika [ Wed Jan 18, 2017 3:21 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

External Rudder Lines

It has always bothered me that the rudder could become unresponsive to the tiller for a variety of reasons. One of the most common is simply that a rudder line slips loose from its rudder connection. It happened to me recently. Fortunately, it was shortly after launching and other than being blown into a dock, there were no serious consequences. Still, it is not something you want to happen when you are a few miles off shore in strong winds. Consequently, I rigged up some external rudder control lines. The bracket at the rudder also serves to clamp the internal lines more securely to the rudder. The setup is simple and shown in the following pictures.

Aluminum bracket for attachment at the rudder

Image


External rudder lines are attached near the rear seat on an open cleat.

Image


Keith

Author:  tonystott [ Wed Jan 18, 2017 8:09 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Keith, my setup is similar, with the following changes:

One side included a short length of bungee, so I can vary the tension trying to pull the rudder to one side (so I can stiffen up the rudder depending on weather conditions).
On the other side, I added a small pulley, so that the rudder line now has 2:1 leverage.

This means that I can steer (in emergencies should an internal rudder line fail), by holding the "control" line and steering against the bungee pull. In practice, it works fine, even with the resistance of the working standard rudder system.

Since this old photo was taken I replaced the carbon fibre extension arms with cut-down "L" sections from an old plastic chair leg :D
Image

Author:  Chekika [ Fri Jan 20, 2017 6:50 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Tony, your system is much more sophisticated than I remembered. Please explain what you mean by "stiffen up the rudder" and why it is needed? Why is the pulley needed (2:1 leverage)? Is it that difficult to hold the rudder in position? And, if it is, why don't you need a pulley on the starboard side?

I've never tried my simple system. I have no I idea if it even works! Got to try it next time out.

Keith

Author:  tonystott [ Fri Jan 20, 2017 9:47 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Chekika wrote:
Tony, your system is much more sophisticated than I remembered. Please explain what you mean by "stiffen up the rudder" and why it is needed? Why is the pulley needed (2:1 leverage)? Is it that difficult to hold the rudder in position? And, if it is, why don't you need a pulley on the starboard side?

I've never tried my simple system. I have no I idea if it even works! Got to try it next time out.

Keith

Keith, with your simple system, you need to use both hands to steer, as you need to uncleat both sides before you can move the rudder. I decided that in an emergency with broken rudder lines, I might need to keep one hand free for other things.

So on the starboard side, I have a short length of bungee cord. This is attached to a line going forward to a clam cleat next to my seat. I tension the bungee just enough to provide resistance on the port rudder line (obviously, the stronger the wind, the more resistance needs to be built in).

So to steer, I pull on the >port< rudder line, against the bungee tension. This means of course, that releasing the port line, the bungee pulls the rudder into full starboard, but it also means that I can work the rudder to best handle sailing through waves.

The 2:1 ratio is there so that in heavy weather (the time when any failure of the standard rudder is going to be most critical), I can still easily control the steering even with increased return tension built into the bungee.

The port line also has a cleat, so I can cleat it off if hand steering is not needed at the time.

I have tried my system in practice, and although it feels somewhat unnatural at first, steering soon becomes as easy as with the normal tiller. By the way, I added a small 1 inch plastic ball on the end of the port line, which fits nicely in the hand for comfortable steering.

Keith, your system is close to being perfect, but I thoroughly recommend adding the bungee and 2:1 tackle, to make it more effective.

Author:  PeteCress [ Sat Jan 21, 2017 7:11 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Chekika wrote:
I've never tried my simple system....
Has anybody tried a proper canoe steering paddle?

I'm thinking the straight blade, stronger shaft, and added area might make it more effective than my regular paddle (which is just a cut-down SUP paddle).

Author:  Chekika [ Sat Jan 21, 2017 7:23 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Pete, I've used a paddle once. Doesn't work well. Similar to a "trailing rudder." The sail easily overpowers the "paddle rudder," requiring that the sail be furled in large part.

Keith

Author:  Chekika [ Sat Jan 21, 2017 8:36 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

tonystott wrote:
Keith, with your simple system, you need to use both hands to steer, as you need to uncleat both sides before you can move the rudder. I decided that in an emergency with broken rudder lines, I might need to keep one hand free for other things.

I don't see why I would need both hands to steer. My lines are long enough that the rudder will turn to one side freely without the other line restraining it. It seems to me, if my boat is moving, I simply need to pull a rudder line in order to steer the boat in that direction. There will be pressure on the rudder that I will be working against. The opposite line is loose. Where it might require both hands would be if I were running directly before wind. Again, I've not used this system. Got to do that to see how it does actually work (or not!)

These external lines are for an emergency. Hopefully, I can get to safe harbor using the external rudder lines, get my boat out of the water, and get the rudder problem (internal lines) fixed.

Keith

Author:  bosab [ Sat Jan 21, 2017 5:27 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Keith can probably show you the pictures in this thread. Back 2011 I broke off the whole rudder. Not just the pin. Sheared the whole Original twist and stow clean off about 5 miles from Flamingo. From the back seat of my TI I paddle steered with my wide blade bend shaft canoe paddle. I am so happy I had it. It was effort tacking into the wind, peddling thru the tack and maintaining steerage. About half sail worked. Impossible to tight tack in the channel(headwind) going into the dock. After I realized no one was going to pull me in or steer me I rolled up the sail, peddled and laid back to keep the paddle biting. TI s do not go into the wind without a rudder at least with the mast up. I was very happy when I touched land after that one.

After hobie upgraded the rudder I was happy again and often practiced steering with the paddle while sailing on all points. If you have the right amount of sail out, trimmed right and the centerboard right, there is not much load on the rudder or paddle to go the direction you are heading. If you don't have the sail trimmed right, have too much out and maybe don't raise the centerboard a bit for off the wind travel the rudder forces increase and you have to keep the paddle in the water all the time.

Just a note I never ever changed a rudder pin on the boat the 5 years I had it. always ready to release the hold down and would use the paddle when approaching the shore.

Author:  kd5crs [ Sun Jan 22, 2017 10:47 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Can y'all provide some tips on the extra hole drilled into the rudder on each side? Did you pre-drill a small hole and just crank in the screw, or did you full on drill and tap the hole? Was it a self tapping screw or a regular wood screw? Did you find you need a neoprene or nylon washer between the screw and aluminum for corrosion?

Or anything else I don't know enough to ask. Thanks!

Author:  Chekika [ Sun Jan 22, 2017 2:05 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Bosab is right about breaking his whole twist-n-stow rudder off. I hated that rudder. But, where he says he was 5 miles from Flamingo, he was actually 11 miles. Well done, Bosab.

Keith

Author:  Chekika [ Sun Jan 22, 2017 3:30 pm ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Here is what was left of Bosab's Twist-n-Stow rudder after that trip in 2011.

Image

Did I say that, "I hated that rudder."

Keith

Author:  Chekika [ Mon Jan 23, 2017 3:33 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

kd5crs wrote:
Can y'all provide some tips on the extra hole drilled into the rudder on each side? Did you pre-drill a small hole and just crank in the screw, or did you full on drill and tap the hole? Was it a self tapping screw or a regular wood screw? Did you find you need a neoprene or nylon washer between the screw and aluminum for corrosion?

Or anything else I don't know enough to ask. Thanks!

kd5crs, I'm sorry, but I missed this post of yours. I simply drilled a new hole (the one closest to the rudder housing) and put an ordinary SS screw in there. The screw further from the housing is the original screw used to hold the internal rudder line. I do think my aluminum bracket holds the internal rudder line better than the original Hobie screw-washer arrangement.

Yes, the SS screw in contact with the aluminum is going to cause the aluminum to corrode. Your suggestion of a nylon washer is a good idea.

kd5crs, that is my problem...what are the proper questions?

Keith

Author:  Chekika [ Mon Jan 23, 2017 6:17 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

Nylatron vs Nylon Shear Pins

I’m not a materials engineer, but as far as I can determine, the shear strength of a Nylatron vs ordinary nylon is only about 5% higher for the Nylatron. The real difference in shear strength of the two aka-brace pins show below, is that the Nylatron pin (pin on right) has the threads filled in. I'm guessing that the Nylatron pin is about 20-25% stronger than the Hobie shear pin. That may just be enough to save someone from an insta-capsize.

Keith

Image

Author:  Chekika [ Mon Jan 23, 2017 7:31 am ]
Post subject:  Re: Have you done any "expedition" trips on the AI?

The 2017 WaterTribe Everglades Challenge will begin at 7 AM, Saturday, March 4, on East Beach of Ft Desoto Park near St Petersburg, FL. Here is a picture of last year's start.

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Keith

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