Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
A hive of inactivity

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.

user:
pass:
register,


                                               

The Softly Bending Kayak

No rudder; it just bends.
  (+7, -3)
(+7, -3)
  [vote for,
against]

Foot pedals are affixed to levers that bend the hull of this flexible, foldable kayak, to the port and the starboard, allowing for directionality change without extra moving parts.
mylodon, Apr 27 2008

A Kayak http://www.guillemo...es/PetrelLaunch.jpg
This is a kayak [vincevincevince, Apr 28 2008]

The argument For flexibility. http://www.guillemo...eBaidarka/index.htm
[2 fries shy of a happy meal, Apr 29 2008]

[link]






       Compare and contrast: //foot pedals... levers// vs. //without extra moving parts//. Could one explain why differential rowing is not good enough?
vincevincevince, Apr 27 2008
  

       Most kayaks already have foot pedals, plus a fragile 2-3 part rudder and lines, plus another line to flip the rudder up and out of the way if you are approaching shallow water, or are going up on the beach, or are throwing it up on some rocks.
mylodon, Apr 27 2008
  

       What they don't have are magical bending watertight magic bends.   

       What good kayaks have is a hull that steers from leaning.
baconbrain, Apr 27 2008
  

       Hypalon is watertight magic bending. Aluminum tubing is likewise magic bending.
mylodon, Apr 27 2008
  

       Rubber joint should work too. It's still pointless.
james_what, Apr 27 2008
  

       It happens that I have a design that could be adapted to make this happen. I know a bit of what's needed here, and I'm not seeing it in the description. This is just a WIBNI.   

       It also happens that I used to make sea kayaks with folding rudders. The rudders are a pain to build, and I certainly wouldn't own one.   

       I've seen folding kayaks, and plastic kayakoid hulls with a hinge in the middle, and I don't see this as an adequate idea. It's a good idea, if it could be built, but I'd say it's been wished for before. And without a bit of how to make it happen, it's not a good Halfbakery idea.   

       To explain my objection, let me ask questions based on the fact that one side of the boat has to get shorter than the other. Where does the Hypalon fold, won't that folding make drag, what keeps the fabric from pinching, where does the aluminum go--does it telescope or hinge--and what happens when a big wave hits the boat and tries to bend it? [-]
baconbrain, Apr 27 2008
  

       Ok, those are good points.   

       I have a 16'6" Hypalon folding kayak, and it is somewhat flexible, as they all are. It is internally 'tensioned' to fit against the skin but also is somewhat internally loose since the internal tension leaves about 2-3" of telescoping action with the side longerons. The cockpit is surrounded by a aluminum tube which --sortof -- hinges with the top central longeron.   

       If that hinge in front of me was strengthened and made a single-axis joint, and I had two levers at my feet, say for simplicity, a T-shaped lever where pressing on one of the top arms presses the bottom of the T against either side of the tip of the nose and distorts the geometry of the boat, it would allow for some kind of degree of turning action. God knows if you put the boat together sloppy it wants to do this kind of turning without any help.   

       My boat would flex as is, what small drag is caused by the rippling hypalon would probably only help the turn; it'd only be when you really stomped on the footpedals that the geometry would distort so much as to bunch up a lot of fabric.   

       I don't even think there needs to be a ton of geometry change required, just enough to tweak your heading. Once you've found (and I'll assume you are a Canadian for this discussion) a baby seal afloat on a drift of ice, and need to rapidly change course to bat it over the head, you can use differential paddling techniques, as proposed above.   

       Also, I don't see a problem with a big wave bending the boat. It wouldn't be too loose. If you were coming into a wave at 45 degrees, you would have to pay attention and tweak the nose over to head into the wave, else you'd be more easily be pushed broadside.   

       But yeah, I didn't put a lot of details in there, however I'd be quite happy to affix a pivot to a rib, put in a lever, strap a bunch of flimsy joints up with duct tape, and give it a try as is.
mylodon, Apr 28 2008
  

       Many people get confused about kayak's and canoes and find it difficult to distinguish between them. However, it's quite a simple task to tell the difference. A kayak is a small, narrow rowboat with a one or two person crew whereas a canoe is a large, African mammal of the antelope family. (Farewell Humphrey Littleton, you will be missed!).
DrBob, Apr 28 2008
  

       //most kayaks already have foot pedals...// Could you refer to the link of what I know as 'kayak' and explain where the pedals, rudder, and lines are?
vincevincevince, Apr 28 2008
  

       //explain where the pedals, rudder, and lines are//
Well, the pedals are just forward of the feet (the clue is in the prefix "ped-") and the rudder is aft of the cockpit, at what we nautical types like to call the "stern".
Not, I confess, as frequently seen as they used to be.
coprocephalous, Apr 28 2008
  

       //why differential rowing is not good enough?//   

       Because it just sucks. I hate differential rowing.
nomocrow, Apr 28 2008
  

       //I hate differential rowing//
But much easier than integral rowing.
coprocephalous, Apr 28 2008
  

       Would bending the kayak actually steer it? I confess to a good deal of ignorance in the matter, but it seems to me that a crooked stick doesn't necessarily float in the direction of its bend. With a rudder attached I think I understand how this would work, but otherwise don't you just have a bent log?
Noexit, Apr 28 2008
  

       I'm pretty sure that if you paddle of the outside arc of a bent kayak, you would turn faster than just paddling on one side of a straight one.
nomocrow, Apr 28 2008
  

       "Kayak" and "canoe" can be confused. An Eskimo kayak is a fully enclosed, decked-over small boat, propelled by a seated person with a double-ended paddle. In England, that is sometimes called a "canoe". The term "Canadian canoe" is used to mean what Americans call a canoe, a small open boat propelled by two (theoretically) kneeling persons with single-ended paddles, facing forward. But American canoes almost all have seats, higher up than a kayak's, and sit-on-top kayaks are popular . . ..   

       A bending kayak would steer a fair treat. Most small boats, if leaned over far, have a bend that can be used for steering. (When I stand in my canoe to pole it upstream, I have to pay attention to shifting my weight, as a bad lean will steer it out from under me quite quickly--oddly, the lean works opposite of a bike, so it's a non-instinctive pain.)   

       [mylodon], you have me convinced, and have shown your work. I hadn't thought about the folding material helping the turn, slight though the folding would be. Thanks for the explain, and good luck with it. [+]
baconbrain, Apr 28 2008
  

       //I'm pretty sure that if you paddle of the outside arc of a bent kayak, you would turn faster than just paddling on one side of a straight one.//   

       How's that any different from the normal way one steers a kayak? I guess I fail to understand why this is better. A sharper turn? That I could get, if it's the point.
Noexit, Apr 28 2008
  

       As a kayaker, I fishboned this because:   

       º Kayak rudders are not flimsy are are extremely effective   

       º Kayak rudders add to stability   

       º Kayaks need rigidity in rough seas   

       º The unequal pressure on the hull would cause severe stability problems (imagine a car with understeer on ice)
Klaatu, Apr 28 2008
  

       Agree with others that the rigidity of the kayak is important to its normal and safe functioning. Perhaps a moveable nose cone arrangement, a la Concorde but moving laterally rather than vertically, would enable the pedal-controlled steering you seek and enable you to get rid of those nonsense folding rudders, but still preserve the overall rigidity.
ConsulFlaminicus, Apr 29 2008
  

       Rigidity schmidgidity. I want one that wiggles through the water like a snake.
nomocrow, Apr 29 2008
  

       I was going to suggest the nose but [ConsulFlaminicus] beat me to it. Perhaps it could have a slight tail aswell that lies close to the surface.
marklar, Apr 29 2008
  

       A paddling aquaintance of mine accidentally baked this one some years ago; he "rescued" a canoe that had been broken across a rock on a popular whitewater river here in Maine. The hull was broken directly across the beam, so after completing the run in his own boat, he hitched back up to the put-in, bushwhacked into where the broken canoe was, and patched it with the handyman's secret weaon, then paddled it down the rest of the way to the take-out. He said that the taped crack acted like a hinge, allowing the boat to bend and flex neatly around the rocks. He has since commented that if it hadn't been for the near-constant repair it required, he might have left it that way.
Alterother, May 06 2008
  
      
[annotate]
  


 

back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle