Hobie Cat Forums

It is currently Thu Nov 20, 2014 2:47 pm

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 15 posts ] 
Author Message
PostPosted: Wed Feb 22, 2012 10:22 am 
Offline
Site Rank - Admiral

Joined: Tue Apr 13, 2010 10:07 pm
Posts: 170
The Etchell Worlds are being sailed off Sydney at present with some of the worlds best sailors involved. If you are interested in high quality racing this is for you - the technoligy available through "trac trac" is amazing check it out at http://www.etchellsworlds2012.org/worlds/.

While sailing to windward a few kms off Sydney yesterday in 10 -12knts south winds, out going tide, a bit bumpy I gave myself plenty of sea room from the cliffs knowing the weakness in the rudder system in these conditions, when the familiar "bang" was heard being GREY rudder pin No.3 breaking. I managed to replace the pin from the boat by folding 1 out rigger back to create more bouancy in the stern and managed the job quite easily. Being then down to only 1 more new spare I returned to the safety of the harbour. Matt I saved the broken pin for you and will send it to you. I was at the Big Day Out and had the Hobie boys look at my rudder system and was advised it was "normal" and OK.

The message to other AI sailors is that these boats are very limited in there ability to sail to windward in choppy conditions so BEWARE of putting yourself on a lee shore in heavy chop it may put you in grave danger. I refer to the 2010 model AI. The new rudder system may be better but I have my doubts because the pin material is the same the shear is still there and the rudder is much bigger to create more power in the shear motion I hope I'm wrong.

Take a look at the seas on the http://www.etchellsworlds2012.org/worlds/ during race 3 as these are the conditions to be avoided in a 2010 AI.

Safe Sailing


Top
 Profile  
 
PostPosted: Wed Feb 22, 2012 10:44 am 
Offline
Site Admin

Joined: Tue May 27, 2003 12:44 pm
Posts: 9222
Location: Oceanside, California
You are referring to your experience with rudder pin failure as a possible limitation. Certainly pedaling and sailing these boats gets them to weather better than most any sailboat... due to the performance of the drive system.

That is odd. Looking at the video ... not really rough conditions and certainly these boats are handling this and more without that many failures. Something odd is going on. How about your launch and landing conditions. Beach? Break? Stressing the pin during launches and landings. We have guys in much rougher conditions not failing pins as often. Are you really slamming the rudder sideways over repeated steep chop? That could cause significant shear load on the pin. Possibly ease up on the sheet or reef if it is that windy. Maybe allow the rudder to swing under the heavy side load pressure.

_________________
Matt Miller
Director of Parts and Accessory Sales
Hobie Cat USA


Top
 Profile  
 
PostPosted: Wed Feb 22, 2012 2:11 pm 
Offline
Site Rank - Old Salt

Joined: Tue May 18, 2010 2:31 pm
Posts: 2753
Location: Kailua 96734
Dave, good job with the on-water recovery. It takes large stones to hang back there in rough water, especially if you are by yourself at the time.

How close together were the 3 failures?

On the new hulls and TI's, the rudder pins/gudgeon are roughly twice as long now and the stresses are distributed better, in my opinion. There have been no reports of failure reported here in the islands that I know of. Rudders were reported snapping before the pins, and that tells you something. In fact, you are one of few to report a gray pin failure of any kind.

The couple of times I broke the old black pins, it was on a hard reach with a slightly trailing sea, which tended to twist the stern regularly. The rocking fatigued the plastic until one good side swell snapped it. Is this similar to the course you were on?

For those who are new to the forum, broken rudder pins were an everyday hazard a few years ago (with the old black models), but statistically speaking, something unusual must be happening to snap the new ones.

If it's a common occurrence for you in moderate conditions, there likely is a mechanical explanation like cavitation, grounding or misaligned rudder parts. You may consider carrying a steel pin along with plastic spares until you figure it out.

Fortunately, our rigs can still be pedaled, paddled or even sailed with a busted rudder, so there is still a margin of safety remaining.

_________________
"THE WIND IS YOUR FRIEND,.."


Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 6:38 am 
Offline
Site Rank - Admiral

Joined: Tue Apr 13, 2010 10:07 pm
Posts: 170
Matt
1.I launch from a concrete boat ramp in very protected waters so that's not an issue.
2. I pull away over large waves and don't slam the boat.
3. It was only blowing 10-12 knts and the boat was travelling easy although the sea were quite steep around the heads with an out going tide going against the wind.
4. I don't cleat the rudder down because it doesn't need it.
" Maybe allow the rudder to swing under the heavy side load pressure." What do you mean?
5. I agree the mirage drive is great.

I was thinking about taking the sharp machine edges around the gudgeons off to reduce the sizzor sheer ability. There is no unusual looseness in the rudder area. I have been in much rougher conditions without breaking a pin.

Nohuhu - I've broken 2 this year, the other was 8 months ago - all in similar conditions - to windward in 3'-5' steep chop. I'm thinking stronger pin or up date the hull. Thanks for your interest.


Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 9:31 am 
Offline
Hobie Tech / Moderator

Joined: Wed May 28, 2003 1:12 pm
Posts: 1023
davew wrote:
4. I don't cleat the rudder down because it doesn't need it.


I would guess this is the cause of your issue - really everyone needs to cleat the rudder down - I'll let other's chime in but that is my opinion... Why don't you cleat the rudder?


Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 10:03 am 
Offline
Site Rank - Old Salt

Joined: Tue Jun 19, 2007 6:14 pm
Posts: 1910
Location: South Florida
I broke 3 pins in about 4 yrs use of my 2007 AI. 2 of those pins broke within 1/4 mi of each other--one broke, put a new one in, and it broke immediately. Nothing special about the conditions or the pin color--at least 1 was gray. The 3 pins broke on port tack (wind coming over the left side of the boat.)

My wife's 2009 has never broken a pin.

My 2011 w/ new vertical rudder has not broken a pin.

I always cleat the rudder down hard.

Keith

_________________
I sail: Biscayne Bay, Everglades to Cape Romano, Ft Desoto, Cedar Key

"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


Last edited by Chekika on Thu Feb 23, 2012 12:09 pm, edited 1 time in total.

Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 10:38 am 
Offline
Site Admin

Joined: Tue May 27, 2003 12:44 pm
Posts: 9222
Location: Oceanside, California
If you don't cleat the rudder down with the twist and stow system, the rudder can / will push back and upon doing so... starts to twist. You likely experience issues turning right at times as well. This puts a side load on the rudder and makes it unbalanced. A agree with Jacques. This is a possible reason for the unusual number of failures you are having. The rudder moving aft causes more load on the whole steering system.

_________________
Matt Miller
Director of Parts and Accessory Sales
Hobie Cat USA


Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 1:04 pm 
Offline
Site Rank - Old Salt

Joined: Fri Dec 05, 2008 2:32 am
Posts: 1790
Location: Terrigal NSW, Australia
Dave, It's interesting that you find you don't need to cleat the rudder and you have all these pin breakages. If I didn't cleat the rudder, my boat would invariably round up in anything more than a light wind. I also never broke a pin. If you try cleating the rudder, as Matt suggests, and still get pin breakages, it might be due to some peculiarity in the geometry of your rudder. I have a new hull now, so you are welcome to have my old twist and stow setup if you want to try it on your boat.

_________________
Image


Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 1:47 pm 
Offline
Site Rank - Admiral

Joined: Tue Apr 13, 2010 10:07 pm
Posts: 170
Firstly thanks Chris for the offer and to all for advice I will take on board and hope the breakages end.

The reason I haven,t been cleating it down was that it stays in the designed groove without help, rarely it hits floating weed and kicks out of the groove and steering loss is obvious.

I can't wait to try it out in the worst conditions I can find, but not on a lee shore cliff. I'll keep you informed.


Top
 Profile  
 
PostPosted: Thu Feb 23, 2012 2:43 pm 
Offline
Site Rank - Old Salt

Joined: Tue May 18, 2010 2:31 pm
Posts: 2753
Location: Kailua 96734
Swapping rudders is a brilliant idea. (I too have one laying in storage).

On my old 2008 hull, I needed to cleat hard in 15-20 knot conditions similar to Daves. The rudder would always pop loose while surfing waves at 10-15knots speeds. And sometimes on fast downwind runs. It would usually reset by itself.

So far, the new straight rudder has not done this.

The reflected backwash Dave describes and warns about, is probably the harshest on the rudder. You can really feel the stresses as you negotiate past sea cliffs and the windward sides of offshore islands. Like sailing in a washing machine.

I totally agree with his words of caution there, and it reminds me to be smart and have a steering paddle ready to grab ...

_________________
"THE WIND IS YOUR FRIEND,.."


Top
 Profile  
 
PostPosted: Sun Feb 26, 2012 1:57 pm 
Offline
Site Rank - Admiral

Joined: Tue Apr 13, 2010 10:07 pm
Posts: 170
Went out Sat to see Etchells last heat - great racing.

I didn't break anything, seas were a little sloppy wind 10-12 while I was out so gentle conditions. I tightened up steering lines before going out and found them a bit stiff. Cleating the rudder down made little to no difference to steering feel so I will continue to experiment.

I recall reading that tight rudder down line results in broken rudder pins?


Top
 Profile  
 
PostPosted: Mon Feb 27, 2012 10:32 am 
Offline
Hobie Tech / Moderator

Joined: Wed May 28, 2003 1:12 pm
Posts: 1023
davew wrote:
I recall reading that tight rudder down line results in broken rudder pins?


I think it might the opposite - I could see that having the rudder not tighten 'down, could cause a failure.
I am not sure why you are tightening the steering lines - they just need to be snug, not tight - this will just make it harder to sweep the rudder handle left and right.

_________________
Jacques Bernier
http://www.hobiecat.com/
http://www.facebook.com/HobieCatCompany


Top
 Profile  
 
PostPosted: Mon Feb 27, 2012 10:37 am 
Offline
Site Rank - Admiral

Joined: Tue Apr 13, 2010 10:07 pm
Posts: 170
Snug is what they are.


Top
 Profile  
 
PostPosted: Mon Feb 27, 2012 11:26 am 
Offline
Hobie Tech / Moderator

Joined: Wed May 28, 2003 1:12 pm
Posts: 1023
Also another thing to check out is the point where the crank exits the hull and the handle is attached there is a brass insert it passes through (on newer boats anyway) if your boat has this brass insert you may need to lube it for better function - we use a marine grease in assembly now but on early boats we didn't and they have been known to get tight on occasion. (I am not sure your boat is of that vintage so just check that it isn't physically binding at that location too)

_________________
Jacques Bernier
http://www.hobiecat.com/
http://www.facebook.com/HobieCatCompany


Top
 Profile  
 
PostPosted: Mon Feb 27, 2012 10:05 pm 
Offline
Site Rank - Admiral

Joined: Tue Apr 13, 2010 10:07 pm
Posts: 170
Thanks JB I'll check it out.
Just came back from an easy harbour sail/peddle and all went well. When I use the hold down line and cleat it "firmly" the steering gets tighter - to the point I consider too tight! I will experiment with tension.
I appreciate your interest.
Cheers


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: Yahoo [Bot] and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group