4 Wheel Drive Boat - looking for builder

Discussion in 'Boat Design' started by PlaningWheel, Nov 26, 2010.

  1. daiquiri
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    I bet Leonardo Da Vinci would have loved to try that one.
     
  2. JosephT
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    JosephT Senior Member

  3. yodani
    Joined: Nov 2010
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    yodani Senior Member

    That is going to be a tough job making that work I mean... We have here in the Danube Delta some floating tractors called Sega and they where build in the 70's for reed cutting. Those are similar in design with this machine and had hydraulic motors on each wheel to make it steer and advance in the water.

    Your design is flawed the way it is as you will not be able to steer it and the moment one of the wheels catches something the whole thing is going to stop no mater how many belts you put on it.

    Putting it in reverse will damage the paddles if boat gets stuck. If you want to use it only in open water that's going to be ok but as soon as you enter the vegetation those paddles will fill up with it.

    As a toy it might work... but to put your money in it and hope to sell lots of them...

    Anyway good luck and I can't wait to see it on youtube just like that screw tractor above... ingenious idea but never made it ask yourself why?
     
  4. cameron.d.mm
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    cameron.d.mm Junior Member

  5. portacruise
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    portacruise Senior Member

  6. PlaningWheel
    Joined: Nov 2010
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    PlaningWheel Junior Member

    To JosephT

    The best of these were built by Chrysler for the U.S. army.
    Lots of rotating surface area. One of the uses is to trench and drain swampy areas.

    [​IMG]
     
  7. PlaningWheel
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    PlaningWheel Junior Member

    To Portacruise

    http://www.foils.org/yourown.htm

    I’ve actually drawn this boat? Didn’t think someone would actually build one. The forward speed would not be very impressive. In an aircraft the ability to hover is very useful however on the water you can simply cut the engine!
     
  8. PlaningWheel
    Joined: Nov 2010
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    PlaningWheel Junior Member

    This is only a model to prove the principal.
    It can only go in a straight line and I’m aware of that.
    For steering there are two choices.
    Caterpillar drive or my preference front wheel drive steering.
    When you turn the wheel on your car the front tire introduces a side force and works best if you’re not braking or accelerating. However if you had studded tires you could power through the turn by biting into the asphalt. A “Planing Wheel” does bite into the water and will power through a turn.

    I define efficiency based on the lift to drag ratio.

    A planing hull max’s out at about 5:1.
    A hydrofoil (under cavitation speed) is about 6.5:1.
    A hovercraft can get up to 10:1.
    I hope to be in the 20:1 range or better.
     
  9. portacruise
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    portacruise Senior Member

    Why do you say the forward speed would not be impressive? This should have the ability to go at least as fast as any present planing displacement hull (probably much faster) and use much LESS energy in doing so. This is because of the complete lack of planing hull friction whatsoever. The rotors are INCLINED, not sitting flat to the water in this design so it will not hover under power in this configuration. If you want to hover with the hydrocopter, you simply cut the engine and the backup pontoons keep the thing afloat. There was also mention somewhere in my readings that it could travel over shallows and even land if the rotors are stiff enough, but it would be a stiff ride unless a suspension was rigged up. Help me to see what am I missing here that you can see?

    Porta
     
  10. PlaningWheel
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    PlaningWheel Junior Member

    To Portacruise

    Ok.

    If you could over-swivel your outboard motor so it’s mostly pointed down it would not be efficient but you would still move forward. If you put 4 motors around your boat you could lift the boat and move forward but would you consider this the most efficient way to utilize the power available?

    If you look at helicopter principals (in particular why the angle of attack of the blades has to be continually adjusted) you can see some of the problems involved.

    Tip speed is the real limiting factor. A fixed hydrofoil blade has a top speed of 40+ knots? before it starts cavitating. So if you spin up these blades to the point where the blade tips are doing 40 knots; any added velocity (moving forward) will start to cause cavitation on the forward swinging blades; before you’ve really gone anywhere.

    As far as skin friction goes the spinning blades are producing a very large amount compared to the "speed made good".
     
  11. portacruise
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    portacruise Senior Member

    Thanks,

    Porta
     
  12. rasorinc
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    rasorinc Senior Member

  13. Submarine Tom

    Submarine Tom Previous Member

    Will you pivot each front wheel complete with fancy steering geometry to match or simply articulate the whole vehicle about the centre?

    -Tom
     
  14. rambat
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    rambat Member at large


  15. PlaningWheel
    Joined: Nov 2010
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    PlaningWheel Junior Member

    To Rambat

    I meant caterpillar steering not caterpillar drive. Patents for these types of vehicles date way back. It’s all about efficiency.
    From his own website he claims a top speed of 39 mph I would expect to do considerably more with the available HP.
     
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