Hobie Cat Forums

It is currently Sun Apr 20, 2014 4:10 pm

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 21 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re: Rudders
PostPosted: Wed Jan 27, 2010 4:59 am 
Offline
Site Rank - Deck Hand

Joined: Mon Jun 23, 2008 7:37 am
Posts: 12
Location: Western Australia
Ok So I will try to tuck the rudders under more. Although last time I did that I got lee helm all the time.
I do tend to run the rig a little too loose but dont have a loos guage to tell you what tension I actually run but the sidestays go loose on the leeward side when we are powered up so I know that is a problem. I also run minimum spreader rake and low diamond tension. I set it to the Mitch Booth tuning guide for crews 180kg as far as rake and tension go. I dont generally touch the diamonds and the mast is fairly straight it has about 40mm of prebend. I dont adjust anything from 5 to 25 knots just more cunningham and heavier thoughts. I tend to let the boat ease up in the gusts and bear away as it comes out of the gusts. I make it smooth minimal movements but it just loads the rudders too much. If I wait till both hulls are in the water to bear away it doesnt happen and I can bear away as violent as I like with one rudder out of the water but as soon as we are in the sweet spot where the hull is just kissing the water I get this cavitation. I dont lift the boards when I go upwind but this was going to be my next option.
I tried setting my boat up exacty the same as Taylors that he won our states with and that didnt make a lick of difference. The only thing that has made any difference is the mast rake when I bought the boat it was at the bottom gudgeon and it was hopeless there and I have changed it to the back of the hatch and now to the corner of the hull. I might need another boat to swap parts till we get it right.
I have emailed Taylor asking him for help awaiting a reply
Thanks once again for your help mark


Top
 Profile  
 
 Post subject: Re: Rudders
PostPosted: Sat Jan 30, 2010 2:54 am 
Offline
Site Rank - Deck Hand

Joined: Mon Jun 23, 2008 7:37 am
Posts: 12
Location: Western Australia
Ok there has been a slight developement. I have asked for dealer assistance and havent had any luck there. So I thought I am going to investagate this further. I noticed a deep gouge where the cheek of the casting been digging into the rudder. I thought this was normal untill I saw that there is 5mm gap. So I grabbed the blade and moved it to where it would touch and I have to move the rudder 5 degrees.
So I pulled the blade off and it is split in half. This explains everything. Wonder what sort of warrently hobie give on such items. It is obviously a manufacturing fault I am not expecting anything but was wondering.
Thanks Guys for all your help especially Mark.
I have an old style set which I will give a run and see what happens


Top
 Profile  
 
 Post subject: Re: Rudders
PostPosted: Sat Jan 30, 2010 9:59 am 
Offline
Site Rank - Old Salt

Joined: Thu Nov 13, 2003 10:00 am
Posts: 383
Location: Long Beach, CA
That sounds like it is the case of your concerns. Hope it is...now get back out and sail!


Top
 Profile  
 
 Post subject: Re: Rudders
PostPosted: Sun Jan 31, 2010 7:47 pm 
Offline
Site Rank - Deck Hand

Joined: Sat May 23, 2009 4:13 am
Posts: 6
Location: Victoria, Australia
Good to hear you found something.
Keep us posted on the change to the other rudders

Mark


Top
 Profile  
 
 Post subject: Re: Rudders
PostPosted: Wed Feb 17, 2010 5:52 am 
Offline
Site Rank - Deck Hand

Joined: Mon Jun 23, 2008 7:37 am
Posts: 12
Location: Western Australia
Hey People
Thanks for your assistance. I took it out on the weekend. I assumed that it was going to be fixed so I changed the rig substantially to better settings that I got from another top Tiger sailor.
The boat went like a dream. I had more boat speed than an Infusion and it did everything it was meant to. I have even got gust response now which I thought was lost forever. I did loose the rudders twice but both time it co-incided with nose dive so I would assume thats normal and we took a step back and it never happened again. I am now happier with my Tiger and wont burn it. I was very surprised that I was quicker than the Infusion it was flat water and about 20 kts. They still beat us but we have pathetic boat handeling skills at the moment so the distance between us would have been much less if we had been on the ball a bit more. we were too exstatic about being able to steer with 2 on trap and not flying forward every gust when the brakes came on.
Thanks again
Bevo


Top
 Profile  
 
 Post subject: Re: Rudders
PostPosted: Fri Feb 19, 2010 9:22 pm 
Offline
Site Rank - Old Salt

Joined: Sat Jul 02, 2005 9:47 pm
Posts: 577
Location: San Diego
Try towing the rudders in. You stated: "I now have a fairly neutral helm upwind but once double trapped the windward rudder stalls on re-entry after flying a hull. " Assuming the foil is ok as you also say it is, there is low pressure on the windward side of the windward rudder. As the rudder hits the water, you see this pressure imbalence as a "stall" or a pocket of air on the windward side of the blade. The windward rudder should be neutral so tow the rudder in significantly (1/4" or so) and this "stall" will go away. I sail a H-20 heavy and have seen similar tiller load/ruddder balance issues not related to rake but tow.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 21 posts ]  Go to page Previous  1, 2

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 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