Quick EXP S/P Thruster.

Discussion in 'Surface Drives' started by tom kane, Nov 2, 2013.

  1. tom kane
    Joined: Nov 2003
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Props can come in many designs but how about a simple wire grinding cleaning wheel for a surface drive or paddle wheel. Moves a lot of water pretty smart
    easy to make, better than a pelton wheel.No cavitation problems or sheet
    cavitation worries.
    Water is discharged depending on rotation and does not stick to the wheel. No problems with hitting something and it can be shielded. Any size and diameter.
    Yes but will it be efficient,who cares if it is safe and reliable and does the job.
     

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  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    So, you just had to stick your drill mounted wire wheel in the sink. I would think a lot of drag associated with this, but on a relatively slow speed craft . . . How much surface area do you think there is, once you count up all the strands engaged? Ventilation would be a problem at high speed. I would think efficiency would be lower than other types of impellers.
     
  3. tom kane
    Joined: Nov 2003
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Nothing will work without friction and drag to get reaction. You can choose your surface area. ventilation would be an advantage like a ventilated surface prop.Why would you think efficiency would be lower unless you tried the principle (or did some calculations) and made some comparisons with conventional practice.
     
  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I'm just assuming about efficiency loses, based on the size and shape of the "paddles", within the wheel. It may very well be proved, that a turbulent wall of water forms between the strands, acting like bigger paddles, but some testing would be in order to confirm what it actually does.
     
  5. tom kane
    Joined: Nov 2003
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Quick EXP S/P Thruster

    The wire wheel (brass wire) puts up a very clean rooster tail of water to the rear and all the water leaves the wheel not like a cupped paddle wheel. There are a lot of different materials (like plastic) that can be used instead of wire strands (which is crippled not straight).
    I mounted one of my old outboard collection on a transom (sideways and steerable) fitted with a paddle (pelton wheel) and also a discarded 10x3 in buffing wheel it worked better than the pelton wheel. Practical tests are cheaper and quicker than some geek pondering calculations for months making computer models and leaving out some important information.
     

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    Last edited: Nov 2, 2013
  6. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I have a trolling motor this would be easy enough to rig up. I do a base line on the sharpie with a standard prop, then rig a simple 90 degree mount with the wire wheel, maybe of various sizes, to get the RPM right. Maybe in the next few weeks if I can remember it.
     

  7. tom kane
    Joined: Nov 2003
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    My motor was battery electric start (20 HP) built in fly wheel started and ran in both rotations with 2 to1 reduction lower case so the wire wheel could only be run about 1400 RPM. A purpose built drive with 6 speed auto should be interesting.Perhaps even an auto back end with 2 drive wheels.
     
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