Pedal Powered Boats

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

  1. cthippo
    Joined: Sep 2010
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    Location: Bellingham WA

    cthippo Senior Member

    I know I'm coming into this a bit late, but I had an idea the other day for a human powered boat and I was wondering if anyone was looking into it.

    I was envisioning one of those twin hull rowboats converted to a paddle-wheel design with the paddle between the hulls. Tonight I was considering the relative advantages and disadvantages of the paddle-wheel design and remembered another kind of pump I have seen.

    Are you familiar with a Tesla Turbine? It consists of a series of plates spaced very close together rotating on a common shaft, something like the platters on a hard drive. The discs are spaces about twice the boundary layer thickness apart and so the adhesion of the water at the boundary layers drags the water along with the plates. There are several designs, one of the more common of which being a center fed centrifugal one. Tesla turbines can be extremely efficient, but work best over a narrow range of operating parameters.

    For a human powered boat which will have a relatively limited RPM range at the shaft and a fixed fluid viscosity, it seems like this may be a viable system.
     
  2. I57
    Joined: Feb 2008
    Posts: 172
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    Location: Melbourne, Australia

    I57 Senior Member

    Dipping Rudders

    Dennis A
    Sorry about the delay in replying, been travelling and back in internet range. The dipping rudders are at a fixed angle, I need to adjust mine as boat is slow at turning. Catch is if angle is greater it gives better turning but slows the boat more when trying to go straight. Am going to fit a small trim tab for straight running and angle the dipping rudders more.

    Ian
     
  3. chilihead98
    Joined: May 2009
    Posts: 8
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    Location: California, USA

    chilihead98 Junior Member

    Cool! :cool:

    Fins are fun.

    Tom McGuinness
    Pacific Tailboats
     
  4. spidennis
    Joined: Feb 2007
    Posts: 519
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    Location: south padre island, texas

    spidennis Chief Sawdust Sweeper

    Tom,
    So just what is Pacific Tailboats up to ?
    I checked the website .....
    looks like it needs updating,
    the "news" is from 2006?
    Tell us more!
     
  5. chilihead98
    Joined: May 2009
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    Location: California, USA

    chilihead98 Junior Member

    Things are pretty much in a state of "suspended animation". I've completely redesigned the tailboat for commercial production...it's now much more attractive than the prototype. Our US patent for the boat issued in 2006. In early 2007, I took delivery of metal parts for approx 100 boats. A new sit-on-top hull has been designed and prototyped at full scale. For improved manoeuverability, the new hull does not have the integral skeg present in the stock Necky prototype hull. It also has plenty of rocker plus a retractable dagger board ahead of the drivers seat...which provides a point of focused lateral resistance like the dorsal fin on a shark, thereby minimizing side slip during turns. I've researched fin materials and suppliers but haven't pulled the trigger yet. I've also not had any shop space to work on the project during what little spare time I've had...this is the biggest hold-up.

    In late 2005, I started working on a large project for Chevron and ever since have been busy as a pair of jumper cables at an Alabama wedding. LOL!! It's been frustrating not to be able to make much progress on the product since late 2006. However, I can assure you the project is neither forgotten nor abandoned. :)

    I'd be interested in licensing the design and/or teaming with another builder to complete the project.

    Kind regards,

    Tom
     
  6. I57
    Joined: Feb 2008
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    Location: Melbourne, Australia

    I57 Senior Member

    Tailboat

    Chilihead98
    I am thinking of fitting a fin drive to the hull of my first pedal boat. It is 5m long, 500mm beam and is a sit in boat. The stability is marginal and I have used stabilisers for it. With a fin drive I could sit much lower in the seat and maybe not use stabilisers. What size fin would you need and what sort of speed can you expect out of it.

    Ian
     
  7. chilihead98
    Joined: May 2009
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    Location: California, USA

    chilihead98 Junior Member

    Ian,

    I expect you should be able to achieve displacement hull speed.

    The stock Necky hull used for the prototype had a beam of approx 35 inches and was 13 ft long....rather barge-like, but could still cruise along a 4.0 mph...which was faster than two adults would normally paddle the same hull. A narrower and longer hull will undoubtedly go faster.

    The hull should be designed to suit your mission objective. If you want straight-ahead speed, then long and narrow is the way to go. However, if you want enhanced maneuverability, then a different hull design is called for. One of the most enjoyable characteristics of the tailboat is it's maneuverability, including the ability to go in forward or reverse directions and tucking in and out of inlets along the shoreline. Most kayaks don't like to turn. Unlike the Hobie Mirage, you never need to paddle the tailboat.

    Sorry...but I can't divulge much about fin sizing or drive kinematics. Well, I could, but I'd have to shoot you. ;) There's a number of subtleties about how the propulsion fin operates due to the unsteady aerodynamic behavior of oscillating foils.

    Regards,

    Tom
     
  8. I57
    Joined: Feb 2008
    Posts: 172
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    Location: Melbourne, Australia

    I57 Senior Member

    Tailboat

    Tom
    I have moved on to a faster better peddle boat and have been thinking of ways of using the hull of my original boat. It has been sitting in the backyard gathering dirt and leaves. The tailboat concept seems a good concept and would not take a lot to fit the drive.
    The purpose of this forum is to share ideas and concepts, not to say I can't divulge things. If you are worried about people taking your ideas then why go on this forum?

    Ian
     
  9. chilihead98
    Joined: May 2009
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    Location: California, USA

    chilihead98 Junior Member

    Ian,

    Most people on the BoatDesign website are engaged in the boating business, as am I. I'm here to keep my pulse on the pedal power industry.

    Hobbyists commonly share their ideas openly with other hobbyists. Businessmen generally protect their intellectual property. I'm generally willing to provide qualitative information on how the boat operates. I hope this helps explain where I'm coming from.

    Kind regards,

    Tom
     
  10. I57
    Joined: Feb 2008
    Posts: 172
    Likes: 6, Points: 0, Legacy Rep: 62
    Location: Melbourne, Australia

    I57 Senior Member

    Tailboat

    Tom
    I would say most people on the pedal boat forum are amateur enthusiasts like myself who design and build their own boats. It is a process of trial and error and by discussing your progress or lack of it the forum helps. I don’t have a problem with a business going on to keep their finger on the pulse. No doubt a lot of us amateurs who put our original ideas on the forum do so knowing others will be using those ideas.
    Don’t worry, I will not be stealing any of your intellectual property or using it.

    Ian
     
  11. chilihead98
    Joined: May 2009
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    Location: California, USA

    chilihead98 Junior Member

    Ian,

    The BoatDesign website is what it is. There are a lot of professional naval architects, engineers, and other marine industry professionals on it. And boats being a lot of fun to sail and build, there are also a lot of hobbyists. We're all free to use it as we wish. And, with luck, the dialogue and give & take benefits all of us.

    I encourage people to ask questions. If you think you would get more info on fin propulsion out of Hobie, by all means, feel free to direct your questions to them. ;)

    Kind regards,

    Tom
     
  12. zipboater
    Joined: Nov 2010
    Posts: 11
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    Location: Mandeville, Louisiana

    zipboater Junior Member

    New Pedal Drive Concept

    I am developing a pedal drive concept which I hope to produce commercially.
    By using some very old mechanical principals and modern materials I have created a propeller drive that yields almost six times the prop speed (at zero load) of the conventional technology. I am about three weeks away from completion of the prototype. There are a several advantages this drive will have, if it works. :idea:
     
  13. spidennis
    Joined: Feb 2007
    Posts: 519
    Likes: 11, Points: 0, Legacy Rep: 124
    Location: south padre island, texas

    spidennis Chief Sawdust Sweeper

    ok, that's just teasing us !
     
  14. NoEyeDeer
    Joined: Jun 2010
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    Location: Australia

    NoEyeDeer Senior Member

    Six times the prop speed at zero load is a meaningless statement on its own. For a start, the prop speed is simply a matter of gearing. You can get any prop speed you like. To be relevant you would have to include other information such as diameter, pitch, and what thrust it can produce when powered by the average human.
     

  15. zipboater
    Joined: Nov 2010
    Posts: 11
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    Location: Mandeville, Louisiana

    zipboater Junior Member

    New Pedal Drive Design

    The design I have doesn't use conventional gears. I haven't filed a provisional or regular patent application but I have dated and witnessed the prior art and a cursory search has not turned up any conflicting patents so far. Many inventors are paranoid of someone stealing their idea before they can "cash in". The fact is, it takes as much effort and money to steal and develop a patentable idea as it does to execute the process in an honest manner.
    I am currently Frankensteining my drive system into a small monohull for testing. I am using an old 13'6" fiberglass AMF Dolphin sailing hull which I have pared down a little to reduce weight. The prototype drive unit is comprised of a 10:1 pedal drive which turns a small aluminum disc (the power take-off). This allows me to power two counter rotating shafts. I am starting with (2) 3-blade props, 7.75" x 12" pitch. To many of you experts out there, this is probably akin to powering a log with an egg beater.You're probably right. We'll see.
    The power take off wheel is 1/4" thick marine aluminum. I am using urethane wheels affixed at (and tracking along) the perimeter edge on opposite sides of the power take off wheel to drive the 5/16" shafts. I am using belts and pulleys to deflect the shafts 9" to port and 9" to starboard. With this prototype I hope to have a cool fishing boat. If this works or shows promise, the next embodiment will be for the purpose of balancing utility and performance. My goal is to produce the second fastest pedal drive boat in the world. One advantage this design will have is that it will allow for a much shallower operating depth. I live in the Lousiana marsh lands so for me that's a necessity.
     
    Last edited: Nov 30, 2010
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