Rudder Pin design

I tried Gflex on some Hobie PE samples. viewtopic.php?f=11&t=12550 Without substantial preparation (flaming the hull as per instructions) it didn't stick better than other epoxies I tried. I think any flexing or vibration would pop it lose, then you's have a mess on your hands. Some misleading advertising on their part IMO.

The only product I've found so far that actually bonds with unprepped PE is the 3M Scotchweld DP 8010, although their instructions do recommend sanding and cleaning. I wonder what Hobie used, or if they just pulled more plastic into that area in the molding process.

For the leak issue... hot melt glue.

We do battle with getting enough material back there and around the pin fixture. In molding these, it requires additional heat and more flow over an area to get the plastic to adhear. This is not simple when you mold hulls with as many built-in features as we do. There are a lot of areas in the hull that we have to consider.

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Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Thanks Mr Giant. I have a D top on my pin with line going over it. It is the original pin. I like going out in rough conditions on the Long Island Sound. Wind gusts over 20 mph and 3-3 1/2 ft waves. Far enough off shore where a pin failure wouldnt be fun. If Hobie makes a brass pin it might be worth the trade off. Im undecided.

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New to PCs and this forum stuff. Had an original Outback and Classic. sold them both for the A.I.. Love the boat and especially this site... (if I can figure out how to use it)

This is from another thread started by Yakaholic but which is pertanent on this thread:

My 209 AI came with slack between hull gudgeon, rudder box and pin diameter which caused a shimmering of the rudder blade through the water. This may well be as Matt stated in that thread caused by the shape of the plastic blade. This sets up a hammering vibration at the rudder attachments and which I believe is the root cause of some rudder pin failures. After just a few outings my pin showed definate signs of damage. Discussed way back in this thread. Anyway I shimmed up the system and not only has the shimmering gone but regular inspections of the same rudder pin show no further deteriation. Interestingly I found original system as supplied seemed to create a binding or sticking of the rudder system on light downwind runs but now with shimming that has also gone away. I would keep a close eye on your pin Yakaholic....Pirate

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Master of the galleon 'Pirates Lot'

I had noticed a little more play in the rudder housing, than the other 2 older Islands. It is where the housing is held in place with the pin. Everything seems to function just fine, but the impression it gave me was that it needed a slightly larger pin. It crossed my mind to look into sticking a stainless washer to reduce the play or shim something somewhere. But then decided I was being too critical and I should just leave it be.

Now you have me wondering - as loose stuff and parts with "slop" - gets me crazy.

It could be designed loose to make pin replacement easier.

My 2 older islands had the original pins - solid rod of plastic with cotter pins on the top & bottom. I wonder if swopping pins out would make a difference?

Do you have pics of what you did and what you used.

TIA

Yak, I simply shimmed up gap between hull appendage and the rudder box using a thin fibro washer so it had no where to move to. Then I pressed on a piece of plastic tubing onto the exposed part of the pin up tight against the rudder box so further reducing any chance of movement. Worked for me though in the future after I am out of warranty, I intend drilling out and bushing the rudder pin holes in the rudder box to 8mm, which is the diameter of the brass insert on my boat. I am thinking though that they may all be a little bit different from each other....Pirate

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Master of the galleon 'Pirates Lot'

Out of an abundance of caution I pulled my rudder pin on my May 2009 hull.
After 3 trips ~16 hours the pin looks perfect - no signs of any wear or deforming.
So, I'm not going to panic or worry overly much.

However.

After careful inspection it appears most of the the play is between the rudder pin and the brass insert. Boat up on stands, I deployed the rudder down and stood on the starboard side facing it. Grabbed bottom of rudder with one hand and top of the rudder with the other and moved it back and forth - in a port to starboard motion. Yes there is quite a bit of play. Mostly pin to brass insert. To verify, I removed the rudder assembly and just checked pin to brass insert tolerance with no rudder in the way. It looks like the pin is too small in diameter by a significant amount - more than one would think acceptable for such a location.

Yes there is also some play between ruddr box and the pin, which a larger pin would also correct.

I bet you could wrap the entire pin in teflon tape and it would still fit, but of course not be a solution. I tried another brand new pin of the same "D" head design and it was the same.
Wish I had an extra "original" pin to try which was solid plastic and used cotter pins top and bottom

Now, it would seem that a simple enough fix to the play I'm seeing is a slightly bigger (in diameter) rudder pin. Maybe the molding process is imperfect, the plastic pin shrunk some after manufacturing, or the brass insert got made with a slightly bigger hole.

It is also entirely possible that Hobie wants to make certain the rudder does not bind when turning left/right and has a generous tolerance, pehaps also to make sure pins don't get stuck and slide out easily to be replaced. The play is a combined effect of pin to box and pin to insert.

I'm not going to second guess Hobie, nor am I going to replace my rudder pin with some other material. I am simply posting my observation to provide feedback for users and engineers in the off chance some corrective measures are necessary.

In the meantime I marine greased the pin and put it back.
I suspect all will be fine because I don't do 25knt winds or 5foot swells.

Yak

If you want a D shaped head grind it down with a dremel. That's what I did with my SS job.

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Yak, for interest can you measure and post the diameter of the pin, brass insert and rudder box holes? As I recall and posted way back earlier on this thread, mine measured:
Pin 7.6mm, Brass Insert 8mm, and Rudder Box 8.4mm. As you can see my rudder box holes are significantly larger than the pin creating lots of play which in my opinion leading to vibration of the rudder blade as it moves through the water. Also there is vertical play betweeen hull fixture and rudder box which would magnify the problem of the plastic rudder assembly biting into the very much softer pins so causing a premature failure.
My thoughts are that different boats have different tolerances thus the reason why some boats experience multiple pin failures while others don't have any such problems. Seems like yours has slack only between brass bush and pin which would be far less damaging on the pin than my system.To reitereate the problem seems to be cured after the system is shimmed and tightened up......Pirate

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Master of the galleon 'Pirates Lot'

Pirate--what problem are you saying is cured? You've only broken one pin. It seems you don't have a lot of experience to make a conclusion. Maybe I am missing something?

Keith

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2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon

I have not read all of the posts. I need an update.

You started the thread. Pirate... 10% of the posts here in this subject are yours. Have you actually failed a pin yet? I read about a distorted one somewhere.

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Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Chekita the problem on my boat I was referring to was shimmering or vibration of the rudder blade not pin breakage. The above figures are correct and I was replying to a question by Yakaholic for his benefit. The problem of vibration of my system seems to be far better with my modifications, and my pin which began deteriating early on has not got any worse a photo of which is contained in this thread. Draw your own conclusions.

Matt, there are not many additions to this thread since you were last on board and may be in your interests to read the lot.
Incidentally it is irrelevant if I have or have not broken a pin. It is clearly a safety issue as the pin is very difficult to replace whilst on the water. This thread identifies that some boats are having unexplainable and multiple pin failures while others not. Further back in this thread you acknowledged this problem existed and committed Hobie to investigate and report.
Lastly I did not start this thread to be a thorn in your side but it remains an important issue and must be addressed with a viable solution forthcoming....Pirate

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Master of the galleon 'Pirates Lot'

just a note from my pin replacement to the old type and i have not had this pin fail after numerous trips. there is a distinct difference in the pin strength between old and new and i now have regained my lost confidence.

Astro, when you say "old type", are you referring to the original pin type; the one that is a solid plastic rod held in place with small cotterpins?

Are any of those still even available?

Wife has 2.5 years sailing on one of those original cotter pin types, and in that same time I only broke one of them, and only because I over tightened the righ/left rudder lines.

Hobie changed to the tapered pins because replacing the cotter pin type was a real chore - rudder lines were in the way.

yep one of those with the cotter pins in each end as you describe