Conveyor belt propulsion brainstorm

Discussion in 'Hybrid' started by putz, Jun 26, 2007.

  1. putz
    Joined: Jun 2007
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    putz Junior Member

    So I'm new on this site and what a vast amount of info. I was thinking about a high speed paddle boat which then led to the conveyor idea.

    What I'm thinking right now is to build a canal in the bottom of the hull. Mount 1 pulley towards the bow, one at the stern. The engine could be mounted at either wheel, so it could run the belt from the bow.

    For the belt, I'm uncertain and open to ideas. Since it will get wet, metal will rust, a synthetic belt will slip, so....

    Also, with the conveyor belt idea. I was thinking of making crescent shaped fins.

    At any one time there would be several cups/fins/whatever in the water at any given time pulling the boat forward. Also angling the front upwards would pull the boat upwards to the top of the water.

    So if this were a feasible idea, then comes in the amount of energy loss.

    Anyone have any info on something like this? Thanks.
  2. PAR
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    PAR Yacht Designer/Builder

    Paddle drive, wheel or belt is not particularly efficient, not to mention the few dozen interesting engineering problems you'd have to contend with. I know of no available information for a drive like this, though study and research by you, into general yacht design and propulsion systems would be warranted. With a firm grasp of the concepts and principles, you may begin to develop solutions, to the numerous engineering issues, in a system such as you describe.
  3. charmc
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    charmc Senior Member

    You can search in google images or you tube for images of snowmobiles travelling on water; there are plenty. You'll note that the ridged belt is very inefficient in water, so the speed falls off drastically. You can make a belt with larger fins/blades; now you are more like a paddle wheel.

    The screw propellor was adapted because it was proven after many sea trials, match races, and pulling matches to transfer power more efficiently than the paddle wheel. Any belt assembly with its drive and tracking sheaves will have more size and mass than a prop and shaft.

    Might be fun to experiment with, but if you're serious about better propulsion, a better question would be, "How could I improve on existing methods of propulsion?" rather than "How can I make a conveyor belt boat?"

    There is a vast amount of info here on propulsion methods, and lots of information on the Web and in texts on propulsion. Check out cycloidal drives and VSP (Voight Schneider Propellor) for a modern version of paddle drive. Might be interesting, although it's not designed for speed.
  4. putz
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    putz Junior Member

    I wasn't sure how the paddle wheel compared with the screw propeller. The biggest drawback I saw on the wheel concept was that most of it was out of the water, maybe 2/3 or more. That's a lot of weight compared with the amount of water it's pushing. If the wheel was stretched out to 2 straight lines with 2 curved ends, you have a lot of area of water being affected. Half of it would be moving water.

    So if the fin part in the water was 6" high, 24" wide, that would be 1 square foot of water it's affecting. If there were 1 fin every 12" on an 8' stretch, you have 8 sqft of water to thrust against at all times.

    I was thinking of using a fabric/plastic lightweight water resistant material to make the fins. Hard to describe but I have a design that somewhat resembles waves. Obviously will need some hard material to hold the crest of the material wave open.

    This is just to push a stitch and glue so I wasn't sure if it was feasible since it's so lightweight.

    I think the snow mobile is too heavy for it's size, it's not buoyant to begin so it would probably push a boat much better.
  5. jehardiman
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    jehardiman Senior Member

    There are some advantages and problems with this type of propulsion system. Google up Dr Patrick Poole. He wrote a paper on this type of propulsion system for one of the HPV was an IEEE (one of the events sponsers) paper as I recall.
  6. yipster
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    yipster designer

    and here some more links
  7. Guest625101138

    Guest625101138 Previous Member

  8. jehardiman
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    jehardiman Senior Member

    Cool article. I'm willing to bet the snomobile track has less slip than the waterbike at the loading necessary to propel it. That's what Dr Poole's papers need to keep the loading down just like a scull oar.
    Last edited: Jun 26, 2007
  9. alexlebrit
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    alexlebrit Senior Member

    I wonder how this type of thing would work on lower speed Human powered boats. I know Rick's mentioned to me before about paddle wheel designs, I could see this as being similar.

    Oh and the maker's site for the Amphib Rick posted is and here's an article about it too
  10. inventing_man
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    inventing_man Junior Member

    Now thats just plain cool! The only draw back.... price ! I havn't contacted them but I'm willing to bet its close to a 25 g rig .
  11. gcarmich
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    gcarmich New Member

    Can't find Dr Patrick Poole's Paper propulsion

    Does someone have the link to Dr Patrick Poole paper from the HPV event? I can't find it on Google.
  12. gonzo
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    gonzo Senior Member

    The only drawback is that the snowmobile sinks as soon as the speed drops.
  13. Mr Efficiency
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    Mr Efficiency Senior Member

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    FAST FRED Senior Member

    At any one time there would be several cups/fins/whatever in the water at any given time pulling the boat forward.

    Had a friend who built a belt from anm old fire hose and small ply paddles.

    He use it in a high tide flow area to spin a smallish generator.

    The length required was more than the water depth where he anchored , so he had too many problems.

    But it did work, "Free Energy !!!"

  15. Stumble
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    Stumble Senior Member

    I assume they chose the closest matching machines possible, but those two really are so far apart it's silly to compare them. The snowmobile had a HP/weight of .37hp/lb while the jet ski is .24hp/lb. The jet ski has about 64% the HP of the snowmobile, no wonder it's slower.

    Add in the larger contact patch because it has to float all the time and there really isnt much of a comparison here.
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