F35 CK- rudder

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Shae77
Posts: 11
Joined: Wed Aug 20, 2014 4:55 pm

F35 CK- rudder

Post by Shae77 »

Hi,

I have the original barn door rudder. Thinking to shorten it to reduce the weather helm, as written on some of the previous threads on this forum.

Is there anyone here that has the dimensions of a reduced rudder for a Cat Ketch F35?
UK F35- Cat Ketch
S/Y India
Limhman Sweden

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Castaway
Posts: 246
Joined: Sat Dec 13, 2008 8:40 pm
Location: Lerwick, Shetland Isles

Re: F35 CK- rudder

Post by Castaway »

Very brave! I reckon the response to the full sized rudder is only average, and shortening it will make that worse unless you deepen it, too. Of course, if you did that, you could extend the lower part forward to give some balance, which would be nice. However, a deeper rudder would prevent you from taking the ground with the centre-board raised; not too great a problem in the Baltic, but tidal waters will be less accessible.

I have found sail trim to be the key to managing weather helm, though a certain minimum seems unavoidable. I can only use my Autohelm 4000 in light airs or running, otherwise I need the power of the servo-pendulum wind vane to keep on course without hand steering.

I've never seen any alternative rudder plans for the F35 CK (F33 in USA).

Good luck, and let us know how it works out.

Regards,
Gerald
Gerald Freshwater,
s/y 'Castaway', (UK F35 cat ketch, centreboard, 1987)
Lerwick Boating Club
Shetland Isles, Scotland

Goose13
Posts: 77
Joined: Tue Aug 19, 2014 7:18 pm

Re: F35 CK- rudder

Post by Goose13 »

Sail trim, very easy fix!!!
Doug and Marie
Millennnium Falcon F33 CK cb #4
1980 wish bone booms Electric Drive

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Peter
Posts: 22
Joined: Wed Sep 16, 2009 4:12 am
Location: Bremen, Germany, UK F35 CB Cat Ketch 'Avante'

Re: F35 CK- rudder

Post by Peter »

On my first Fairways F35 in 1995 the PO had cut off the rudders trailing edge by about 20 cm/8 in. He then used the cut off part as a tim tab to be steered by the motor of his Autohelm wheel pilot as this was not able to handle the forces of the barn door rudder in any wind. According to the PO this worked ok.
When I bought the boat in the Carribean I did not trust it to bring me back safe cross the Atlantic to Europe. So I got rid of the trim tab and installed a Windpilot Pacific instead and this worked very well. Never had any steering problems with the shortened rudder even in a F10 wind with steep following seas on our way from Bermuda to the Acores.

Regards,
Peter

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Castaway
Posts: 246
Joined: Sat Dec 13, 2008 8:40 pm
Location: Lerwick, Shetland Isles

Re: F35 CK- rudder

Post by Castaway »

Peter; interested to hear your experience. We have a Windpilot on Castaway, which works very well. The PO had pin attached so that he could remove the wind vane and connect a 'push-pull' Tillerpilot, getting the power of the servo rudder and the compass course of the Tillerpilot. I found it fiddly and confusing to set up – we had usually arrived by the time I had it working correctly.
Gerald Freshwater,
s/y 'Castaway', (UK F35 cat ketch, centreboard, 1987)
Lerwick Boating Club
Shetland Isles, Scotland

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