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PostPosted: Tue Sep 04, 2012 11:02 am 
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My second AI had the control lines so tight that i broke two pins during original assembly. We broke one on this boat underway yesterday. Is there an accepted method for detensioning the control cables to facilitate easier pin replacement?

Appologies if this has been covered already

Thanks!


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PostPosted: Tue Sep 04, 2012 11:39 am 
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Un-cleat the rudder hold down line and both lines should both be loose enough to remove/replace the rudder pin. Easy to forget in the excitement of a pin break.

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PostPosted: Tue Sep 04, 2012 12:17 pm 
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KayakingBob wrote:
Un-cleat the rudder hold down line and both lines should both be loose enough to remove/replace the rudder pin. Easy to forget in the excitement of a pin break.


thanks
You would think so, but they are super tight on this boat when uncleated.


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PostPosted: Tue Sep 04, 2012 1:28 pm 
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What model & year?

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PostPosted: Tue Sep 04, 2012 2:29 pm 
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narwhal:
There should not be much tension from the steering lines on the rudder pin. Also the rudder up/down lines are on bungy cords so they should not be left under tension (or they stretch out and become useless).

I have noticed on my TI that depending on the temperature of the hull, the entire boat grows and shrinks an alarming length. I know if I adjust the steering cables when the boat is very warm (like in the sun), once the boat cools down (like in the garage at night, or in the water) the cables are then very loose. As an Engineer I can explain.

(boring technical part)

The cooeficient of expansion for polyethelene is .000111" per degree per inch.
If the temp rises 75 degrees (example from 50f to 125f.... extreme example of sitting in the sun in your yard (summer), and sitting in your garage in november).
calculation
75 times .000111" = .008325" per inch expansion using a 75 deg rise.

18.5 ft x 12 = 222 (how many inches long the boat is)

.008325" x 222 = 1.848" ( the entire boat grows in length almost 2 inches when the temp of the hull rises 75 degrees).

What this means is if the steering lines we adjusted in the summer on a hot day, and you take the boat out into lake michigan, there will be 1 inch of slop in the control lines, that needs to be adjusted.
The cooeffieciency of expansion rate on the Ultra high density polyethene (spectra) lines is only 60 ( roughly half that of the PE hull), ie... half the length of the boat (length of control lines) times 2 (2 lines) works out to around 1 inch of play (roughly) with a 75 degree rise.

(end of boring technical part)

I usually end up adjusting my steering control lines every few weeks.
In my opinion there should be little to no tension (or very little) on the steering control cables. If they are very tight, and you adjusted the control lines in the cool, then put the boat in the sun, you could break the rudder pin, or control lines (one of those insermountable forces just like ice freezing).

You don't have to believe me, just measure the length of your boat with a tape measure in the garage, then sit it in the sun for a few minutes, it will grow over an inch and a half. So in the summer my boat is 18.8 iches, and in the winter it's 18.6 inches (lol).

The whole reason I found this expansion thing out is I have a solid aluminum bow sprit that mounts to the bow and is bolted to the front AKA braces (about 7 ft long) (which I made during the winter), . It didn't line up (too short) when I tried to mount it on a warm day in the summer (measured it three times and it was still too short LOL).

Hope this helps you.
Bob

References:
cooeficient expansion tables (http://www.engineeringtoolbox.com/linea ... -d_95.html)


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PostPosted: Thu Sep 06, 2012 1:40 pm 
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KayakingBob wrote:
What model & year?

2012 Adventure Isalnd


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PostPosted: Thu Sep 06, 2012 2:59 pm 
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Without the up and down lines cleated, there should be a little tension on the rudder lines, but not anywhere near so much as to make changing the rudder pin difficult. You may want to bring your boat to your Hobie dealer and ask them to check the internal lines and show you how they change a pin to see what the problem may be (crossed lines, knots hitting, too tight bungees??). Something doesn't sound right.

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PostPosted: Thu Sep 06, 2012 4:09 pm 
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Agreed. Something is not right


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PostPosted: Thu Sep 06, 2012 4:53 pm 
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On a slightly different tack (but still on-topic I guess), I have looked at how fiddly the split ring is, that is supposed to retain the rudder pin, and know without a shadow of doubt that I could not fit that ring without a set of dedicated split ring pliers (I am a diabetic and my fingers have lost some sensitivity, making very small tasks difficult). Let's not even begin to imagine doing this while at sea...

However, with very little work with a needle file, I could very slightly elongate the hole vertically (thus minimising any potential weakening of the pin) and secure it with a 2mm wide nylon zip-tie, locking it by sliding another onto it on the other side of the pin and snipping off the excess. This seems to me to be far more practical to do away from land, and I suspect just as effective as the split ring.

Any thoughts?

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PostPosted: Thu Sep 06, 2012 5:13 pm 
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Except for when transporting, I don't see the necessity of the ring, so I probably would not put it on if changing the pin on the water.

I've used SS cotter-pins on early AI rudder pins instead of using the supplied ring.

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PostPosted: Thu Sep 06, 2012 5:17 pm 
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Tonystott:
I have fat fingers and have had to replace a couple rudder pins while on the water also. It is a serious pain with no tools. When I got the new replacement pins I bent the end of the split ring with a pair of long nose pliers so can install next time with no tools ( in case it happens again.)
Kind of the same idea as yours.


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PostPosted: Mon Sep 10, 2012 6:49 am 
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Thanks for the replies. I was able to replace it without much difficulty. I must have been doing somethng wrong during the original installation when i broke two pins.

I would still not look forward to having to replace it in open water during rough conditions.

Thanks again!


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