Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Sailboats
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-06-2008, 05:33 PM
fercammo fercammo is offline
 
Join Date: May 2008
Rep: 10 Posts: 4
Location: mexico
how do i make a kick-up rudder for my snipe

i have a snipe sailboat from the seventies, i want to build a kick up rudder for this sailboat, does any body knows how to do it?, does any body has a pattern?
thank you
fernando
Reply With Quote
  #2  
Old 05-06-2008, 06:00 PM
Raggi_Thor's Avatar
Raggi_Thor Raggi_Thor is offline
Nav.arch/Designer/Builder
 
Join Date: Jan 2004
Rep: 696 Posts: 2,457
Location: Trondheim, NORWAY
Very basicly you have a rudder blade pivoting on a bolt between to covering plates, often in plywood.

From http://marina.fortunecity.com/breakw...0715/index.htm :
Attached Thumbnails
how do i make a kick-up rudder for my snipe-rudder1.gif  
__________________
Regards, Kvedja, mvh,
Ragnar Thor Mikkelsen
www.MBOATS.no
Reply With Quote
  #3  
Old 05-06-2008, 09:11 PM
alan white's Avatar
alan white alan white is online now
Senior Member
 
Join Date: Mar 2007
Rep: 1168 Posts: 3,270
Location: maine
Quote:
Originally Posted by fercammo View Post
i have a snipe sailboat from the seventies, i want to build a kick up rudder for this sailboat, does any body knows how to do it?, does any body has a pattern?
thank you
fernando
To make a rudder for the Snipe, see if you can Google the class association. They might help you to get a drawing of the correct original rudder.
Raggi shows how the mechanism is arranged.
I've built a few rudders for boats without any idea what dimension or shape they should have been and all of those boats sailed well. You can easily get a drawing of a Snipe rudder and come close to scaling it from the drawing.
If you need to know how to make one, 3/4" (18-19mm) plywood for the blade and head stock, and 3/4" plywood for the cheeks. The cheeks can go all the way up the head stock and the tiller slot can be an interruption in the head stock with the cheeks to each side of the tiller slot. Or you can have the tiller be fitted around the head stock with the cheek pieces cut off just below the tiller.

Alan
Reply With Quote
  #4  
Old 09-23-2011, 08:42 AM
CutOnce CutOnce is offline
Senior Member
 
Join Date: Jul 2010
Rep: 205 Posts: 426
Location: Water's Edge
Quote:
Originally Posted by alan white View Post
To make a rudder for the Snipe, see if you can Google the class association. They might help you to get a drawing of the correct original rudder.
Raggi shows how the mechanism is arranged.
I've built a few rudders for boats without any idea what dimension or shape they should have been and all of those boats sailed well. You can easily get a drawing of a Snipe rudder and come close to scaling it from the drawing.
If you need to know how to make one, 3/4" (18-19mm) plywood for the blade and head stock, and 3/4" plywood for the cheeks. The cheeks can go all the way up the head stock and the tiller slot can be an interruption in the head stock with the cheeks to each side of the tiller slot. Or you can have the tiller be fitted around the head stock with the cheek pieces cut off just below the tiller.

Alan
I have an older Snipe, and the rudder is not a trivial conversion to kick up, due to it's noteworthy angle to the stern. It's not the same as a rudder with a vertical stern and normal pintles and gudgeons.

From a quick look, the rudder headstock will have to be increased in size a fair bit to retain the same strength and ability to resist twist under load. The solid integrated headstock/rudder blade in the OEM part is narrower than a kick up part would be at the same strength. The actual rudder blade is vertical, with about a 30 degree (guesstimate) turn at the headstock to match the stern profile.

Since rudder size, shape and balance is more important in dinghies for normal sailing, you can't change things radically without the potential for creating handling issues. Besides, once you move too far off the class sanctioned and measured rules, it isn't a Snipe anymore. The rudder loading is off axis to the pintle/gudgeon pair already on the Snipe.

I'd build/buy a proper used Snipe rudder and be done with it. This way you won't screw up the resale value, the ability for future folks to race in class races and it will handle as it is supposed to. Some things are worth fooling around with, and some things aren't. The real trick is to know which ones are worth your time.

--
CutOnce
Reply With Quote
  #5  
Old 09-23-2011, 12:21 PM
alan white's Avatar
alan white alan white is online now
Senior Member
 
Join Date: Mar 2007
Rep: 1168 Posts: 3,270
Location: maine
The rudder design shouldn't seriously devalue the boat since it can be easily replaced by the buyer one day at the cost of a genuine rudder.
Without an example to copy, it's true that any kick-up rudder has to be engineered to perform well.
As a general rule, the blade itself should be exactly like the original's (so the water can't tell which rudder, kick-up or non is being used), and there should be enough play to allow easy pivoting without binding but also tight enough to limit sideways wiggle to a minimum. It's handy to have a pennant to raise the blade and a cleat on the rudder cheek (or led up the tiller) to secure it. The blade must have a down-haul pennant too unless ithe blade is lead weighted. The downhaul locks the blade down so a bungee works well to allow the blade to spring up easily upon grounding. Also, the blade should have a raised position that clears the waterline of the hull to reduce drag and to reduce grounding damage.
I've built lots of rudders to my own design in the days before the internet made finding designs easier. None had problems so I guess the dimensions and profile were close enough. To some, this would not be a solution but some are capable of some seat-of-the-pants engineering. However, it's hard to tell who is and isn't capable of the job.
Reply With Quote
  #6  
Old 09-24-2011, 02:51 AM
PAR's Avatar
PAR PAR is offline
Yacht Designer & Builder
 
Join Date: Nov 2003
Rep: 2891 Posts: 8,798
Location: Eustis, FL
Gonzo's memory is better then mine on this little boat, but I think the stock rudder is a hardwood laminate, not plywood. The solid wood laminate makes much more sense from a loading and durability point of view.

A kickup assembly is a fairly easy thing to engineer on the fly. A U shaped rudder head that captures the upper portion of the blade, of course the blade, a pivot bolt and tiller. You'll want a down haul, fitted into a auto release cleat, which typically runs up behind the pintle bracket arms or many use a simple bungee cord, which serves the same purpose.

As to it's position and relationship with the boat, it's transom rake, etc., well this is all meaningless banter. A snipe is easily balanced with the skipper's butt. Moving the rudder the insignificant amounts necessary to use a kickup feature, is frankly meaningless in the balance of a dinghy, where a good fart will upset sail trim.

Fernando, if you send me an email, (click on my name) I can send you a stock kickup rudder drawing for a well raked transom, which can serve as a guide to making one for yourself. It's super simple, requires very little wood and works well.
Reply With Quote
  #7  
Old 09-26-2011, 09:12 AM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 1397 Posts: 7,216
Location: Milwaukee, WI
My memory is better because I still sail them . There were many that used kick up rudders for shallow water, but were not allowed to race in formal competition. The shape is the same but the blade is metal between two 3/4" wood cheeks. A bungee cord holds the blade in place, or a pin.
__________________
Gonzo
Reply With Quote
  #8  
Old 10-21-2011, 05:39 PM
Larry Sabiston Larry Sabiston is offline
 
Join Date: Oct 2011
Rep: 10 Posts: 1
Location: Atlanta, GA
Fercammo, Thought I was the only person trying to build a kick-away rudder for an "older" snipe. I am going to add sailing in salt water with lots of tide fluctuation and sand bars. I have modeled a modified swing keel and a kick-away rudder. Plan to make the rudder from oak at this point. Suggest you look at a kick-away design on idasailor.com. Very techno (and expensive), but good good approach to the problems of running aground. I'm thinking about copying it for my Snipe.
Reply With Quote
  #9  
Old 10-22-2011, 07:49 AM
gonzo's Avatar
gonzo gonzo is offline
Senior Member
 
Join Date: Aug 2002
Rep: 1397 Posts: 7,216
Location: Milwaukee, WI
The original plans for the Snipe included a swing centerboard option.
__________________
Gonzo
Reply With Quote
  #10  
Old 10-24-2011, 12:51 PM
fercammo fercammo is offline
 
Join Date: May 2008
Rep: 10 Posts: 4
Location: mexico
kick-up rudder

Quote:
Originally Posted by Larry Sabiston View Post
Fercammo, Thought I was the only person trying to build a kick-away rudder for an "older" snipe. I am going to add sailing in salt water with lots of tide fluctuation and sand bars. I have modeled a modified swing keel and a kick-away rudder. Plan to make the rudder from oak at this point. Suggest you look at a kick-away design on idasailor.com. Very techno (and expensive), but good good approach to the problems of running aground. I'm thinking about copying it for my Snipe.
Larry: I already built a kick-up rudder with an old windsurfer centerboard and two cheeks of aluminum, it works really well and is cheap. i can send you pictures and measurements if you want.
I would love to have a swing centerboard, if you have any ideas please let me know.
Fernando
Reply With Quote
  #11  
Old 10-26-2011, 02:04 PM
CutOnce CutOnce is offline
Senior Member
 
Join Date: Jul 2010
Rep: 205 Posts: 426
Location: Water's Edge
Quote:
Originally Posted by gonzo View Post
The original plans for the Snipe included a swing centerboard option.
I've sailed Snipes for years, been a member of the class association and have never heard of this. I still own an elderly Snipe - a 1974 Ontario boat with steel daggerboard and one piece mahogany rudder.

I've searched the SCIRA site and googled for a Snipe swing up centerboard with no results except your post.

I'd really appreciate a link to this info - it would be news to me. I've been wrong more times that I can count, so I'm open to new info.

The class rules are very clear - modifying the board(s) in any way , other than the old style steel (not competitive, but grandfathered in to keep the old guard happy) - and the new aluminum boards are allowed - in the old rounded front style (steel) and the new trapezoid shape (aluminum) plate metal. There is a one inch bevel allowed on the forward and trailing edges,

Anything else is not a Snipe as far as the class association is concerned.

--
CutOnce
Reply With Quote
  #12  
Old 10-26-2011, 03:10 PM
Doug Lord's Avatar
Doug Lord Doug Lord is offline
Flight Ready
 
Join Date: May 2009
Rep: 838 Posts: 5,123
Location: Cocoa Beach, Florida
Quote:
Originally Posted by CutOnce View Post
I've sailed Snipes for years, been a member of the class association and have never heard of this. I still own an elderly Snipe - a 1974 Ontario boat with steel daggerboard and one piece mahogany rudder.

I've searched the SCIRA site and googled for a Snipe swing up centerboard with no results except your post.

I'd really appreciate a link to this info - it would be news to me. I've been wrong more times that I can count, so I'm open to new info.

The class rules are very clear - modifying the board(s) in any way , other than the old style steel (not competitive, but grandfathered in to keep the old guard happy) - and the new aluminum boards are allowed - in the old rounded front style (steel) and the new trapezoid shape (aluminum) plate metal. There is a one inch bevel allowed on the forward and trailing edges,

Anything else is not a Snipe as far as the class association is concerned.

--
CutOnce
====================

I've heard of centerboards on old Snipes-and found this:

http://forum.woodenboat.com/archive/...p/t-13135.html johnw 10/5/2005

"Some Snipes were built with centerboards instead of daggerboards, I think as recently as the 1940s. This is no longer class legal, but if you're a daysailer, does this matter? If I weren't racing the boat, I might have built a centerboard or given it a wide enough slot that I could use 3/4 in plywood for the daggerboard."
__________________
yes, it is a revolution
---"So (yet) another new world begins."
Andrew Hurst, editor of Seahorse magazine, August,2011
Reply With Quote
  #13  
Old 10-26-2011, 05:08 PM
CutOnce CutOnce is offline
Senior Member
 
Join Date: Jul 2010
Rep: 205 Posts: 426
Location: Water's Edge
Quote:
Originally Posted by Doug Lord View Post
====================

I've heard of centerboards on old Snipes-and found this:

http://forum.woodenboat.com/archive/...p/t-13135.html johnw 10/5/2005

"Some Snipes were built with centerboards instead of daggerboards, I think as recently as the 1940s. This is no longer class legal, but if you're a daysailer, does this matter? If I weren't racing the boat, I might have built a centerboard or given it a wide enough slot that I could use 3/4 in plywood for the daggerboard."
Interesting. Historically a portion of American sailors have referred to anything without a fixed keel as a centerboard dinghy - not understanding or caring about boats without a fixed keel. As well, some of these people may have considered the large planform radius on the leading edge of the (older style) Snipe daggerboard (picture attached) as "kick-up".

--
CutOnce
Attached Thumbnails
how do i make a kick-up rudder for my snipe-p3060409.jpg  
Reply With Quote
  #14  
Old 10-28-2011, 07:51 AM
kettyperrien kettyperrien is offline
 
Join Date: Oct 2011
Rep: 10 Posts: 4
Location: USA
bro,
basically you have rudder pivoting on a bolt between covering the plates.often in plywood(metal).
__________________
[url=http://www.martiniguide.net/]martini recipe[/url]
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for Kick-Up rudder idea/designs. LP Sailboats 16 04-16-2008 07:43 AM
Best Type of Wood to Make a Rudder?? TheSound Wooden Boat Building and Restoration 10 09-25-2006 09:47 PM
How to build a Kick-Up Centerboard and Rudder Free Pirate Boatbuilding 10 07-17-2005 08:49 PM
Can I make Centerboard and Rudder like this? dougworm Fiberglass and Composite Boat Building 5 12-09-2004 10:55 AM
Kick-up Rudder Lew Morris Sailboats 4 11-12-2002 07:47 PM


All times are GMT -5. The time now is 03:32 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net