Pedal Powered Boats

Discussion in 'Boat Design' started by Guest625101138, Jul 14, 2008.

  1. Scheny
    Joined: Feb 2012
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    Location: Vienna/Austria

    Scheny Junior Member

    Ok, drag calculation is ready. It is calculated using water only, so values should be way lower in reality.

    But for 2.6m, the drag seems not so bad to me.

    @I57: I use a HTD 5M belt 15mm with a twist. Currently my living room and kitchen are renovated and the boat has to wait for a few more weeks.

    @Rick: Can you send me a FreeShip 2.6 model of one boat with a speed and drag value, so I can run this in CFD and compare how accurate the program is with fluid only calculation?
     

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  2. Luposian
    Joined: Jun 2012
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    Location: Sierra Vista, AZ

    Luposian Junior Member

    Pedal powered boating...

    I just had my first experience, in a pedal boat. Actually, my first experience being in ANY boat, I was in complete control of! And, as I pedaled and steered, it got me to thinking... "How could this boat be made better?"

    The pedaling action seemed a little primitive and "clunky". I could see how there was no complete support, so that, over time, two people pedalling could eventually wear out the bearings, over-stress the plastic, and cause leaking (which was already happening). The rudder steering also seemed rather difficult (hard to turn), though the left/right "steering stick" seemed quite natural for control logic.

    I have seen forward/reverse steering sticks and, while they offer more leverage (your bicep gets involved instead of just your forearm), they seem very awkward, steering logic-wise.

    I've gotten a picture from a eBay seller that shows the underside of one of these pedal boats, so now I have a good idea how the hull is fashioned. Could this be improved? I can also see the rudder/rod linkage (poorly implemented, I think).

    I've gotten to thinking that maybe steering could be more efficient and the pedaling mechanism made more stable (higher quality design), so that the plastic (or whatever hull material) and bearings almost NEVER wear out.

    Hopefully, this could be done without making these types of boats much more expensive than they already are, yet far more reliable and easier to pedal/control.

    I was planning on buying a cheap pedal boat on eBay, to use as a template, for improvement (in designing a better one), but my wife refuses to let me buy one, when our finances are still so tight...
     
  3. Scheny
    Joined: Feb 2012
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    Location: Vienna/Austria

    Scheny Junior Member

    @Luposian:
    I am sorry to say that your wife is right. You will not buy a cheap Jeep if you want to build a Ferrari with a few tuning parts. These rental boats are built in such way, that part count is minimized and parts are simple.

    The rudder requires strength because it is not "balanced", but you can`t balance a flat plate, as it will not bear the forces. The sideforces are here limited by the strength in your arm, as waterflow of the unbalanced rudder tries to push it back. The bearing is made out of a simple block of Delrin. This is easy and o produce and costs nothing. The little bit of leakage doesn`t harm and is on the other hand wanted as a lubricant. The hull is designed for maximum buyoancy and that it can be made with only two pieces. The bow has to be the opposite of sharp, so that it does less harm in case of a collision or hard docking. Sharp edges are prone to breaking first.

    If you want an efficient boat, you will have to build it on your own like the rest of us here in this thread. Sorry.

    Maybe you can write your requirements, then we can help you.
     
  4. portacruise
    Joined: Jun 2009
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    Location: USA

    portacruise Senior Member

    Scheny:

    This is a boat for NON boaters, which is one of the largest markets for HPB!

    http://www.boatdesign.net/forums/boat-design/electric-assist-43432.html

    Post #10, #11.

    Porta



     
  5. tinhorn
    Joined: Jan 2008
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    Location: Massachusetts South Shore.

    tinhorn Senior Member

    Lotsa ways. Scroll to the bottom of this page: http://www.svensons.com/boat/ . Google "human power boat patents". Think only pure thoughts and you may be rewarded by stumbling across an out-of-production pedal boat for big boys. I can't think of many things that have been more enjoyable while clothed than pedaling the river near my house.
     

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  6. h20m@n
    Joined: Jul 2012
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    Location: kent UK

    h20m@n New Member

    I have long been a bike rider living by water, i have always wanted to combine the two. paddling is great and all, but i already have the engine for pedals.

    i love this design for the simplicity of the drive:http://www.profimedia.si/picture/32nd-international-waterbike-regatta-preparations/0093271553/


    i would like try building a solo version of this boat. as a novice boat builder i am unsure of a few things.

    1.the prop shaft will have to leave the sprocket at an angle so that it can exit the hull in the water. what kind of joint here would allow rotation at an angle?

    2.how would you support the rotating shaft within the hull? what kind of bearing is practical here?

    3. how do you seal the exit of the propshaft? a stuffing box looks like it would cause too much friction int his low power drive.


    any ideas/info would be much apreciated!
     
  7. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    There probably is an answer in the 1623 posts before yours in this thread.
    Have fun.

     
  8. Scheny
    Joined: Feb 2012
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    Location: Vienna/Austria

    Scheny Junior Member

    @h20m@n: To make it short:

    You need only about 10-15 degrees angle. With that construction you can simply twist the chain. So only mount the smaller gear in the angle you would like. For a shaft going through the hull I would recommend a stainless steel rod for simplicity. Maybe 8mm. Use a simple ball bearing on both ends. For sealing, take a piece of plastic and make a bore with exactly 8mm. That will be enough.

    For good sealing, use Teflon, but Delrin will be more easily available. Delrin has "self lubricating" capabilities, which means it feels like it is bathed in oil. If the bore is precise, it will seal enough and run smooth without too much additional drag.

    If you feel uncomfortable using a steel ball bearing at the stern, there is a company selling affordable ball bearings in Delrin with ceramic balls.

    If you need more info, it is really worth reading through the last 1700 postings.
     
  9. TexPoll66
    Joined: Jul 2012
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    Location: Sydney

    TexPoll66 New Member

    Cadence - conversion to Milltrack "square taper"

    Possible?
     
  10. portacruise
    Joined: Jun 2009
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    Location: USA

    portacruise Senior Member

    h20:

    Check out the pics for the sidewinder on this site, could be helpful, with some modifications to your configuration:

    http://www.recumbents.com/wisil/hpb/boat.htm

    Porta




     
  11. I57
    Joined: Feb 2008
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    Location: Melbourne, Australia

    I57 Senior Member

    h20
    The sidewinder is a simple way of doing a pedal drive system on a boat, that is if you want to have a crick in your neck. I'm probaly biased here but the simplest and least messy way is to use Ricks layout that he has on his V series of boats. A bike crank with chain running to a 90 deg gearbox then a flexible shaft running down the side, no holes in the hull. The shaft can be either 8mm spring steel or 10mm aluminium, the prop size would depend on the gear ratio and amount of power you can produce. With the setup I have it is a 7.4X ratio, every turn of the crank gives 7.4 turns at the prop. The boat is 5m long with a 300mm beam and two 2.4m outriggers, another advantage is the shaft can be lifted out of the water and the boat sit flat on the beach.

    Ian
     

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  12. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Ian,

    How much does your new boat weight? Very nice looking by the way. Did you build it with Rick's graphite panel construction?

    Did Rick ever make the magnetic drive that was talked about some time ago?

    Marc
     
  13. I57
    Joined: Feb 2008
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    Location: Melbourne, Australia

    I57 Senior Member

    Marc
    Boat weighs 27.5kg, including outriggers. Its Ricks V15 design, constuction is of 3mm plywood skin and frames using fibreglass for holding it together.
    Rick did make a 90 deg gearbox using magnets instead of gears, was heavy and slipped a bit under high load.

    Ian
     
  14. Dennis A
    Joined: Aug 2009
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    Location: Amersham bucks uk

    Dennis A Junior Member

    Waveless Concept

    I am always searching for the perfect pedal boat which should be fairly fast,manuverable, light and easy to transport. I have been studying the Open Waterbike Waveless Zero Concept.
    This initially appears to be full of new ideas but is in reality is a small pedal boat application of a displacement glider, that are normally motor driven boats around 10 m long.
    The Waveless bike claims a cruising speed of 12 km/h with a maximum speed of 14 km/h. These speeds if correct would be very attractive for a boat of only 2.6 m in length.
    With the upper hull section similar to a planing hull, at maximum speed would this boat glide on the water surface.
    The short boat length would help achieve planing but can this concept achieve the impossible.
    Dennis
     

  15. I57
    Joined: Feb 2008
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    Location: Melbourne, Australia

    I57 Senior Member

    Dennis
    The boat Scheny proposes is an interesting concept. As I've said earlier its a small boat that would not be hard to build. Make it and put it to the test, its the only way to know if it will work or not.

    Ian
     
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