low rpm propeller

Discussion in 'Props' started by Rodrigo Alves, Jan 11, 2023.

  1. Rodrigo Alves
    Joined: Jan 2023
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    Location: Sao Paulo - Brasil

    Rodrigo Alves New Member

    Hello friends, I have a project for a small pedal boat. After a lot of research, I still haven't decided which propeller to use. It will be for low rotation: one turn on the pedal corresponds to 25 turns of the shaft where the propeller will be installed. I watched a video of a German who, after some research, used a model airplane propeller and it worked fine. What do they tell me? Thanks
     
  2. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    A model airplane prop is fairly small in diameter and cannot really be "slow rotating" if it is to generate any significant thrust. As a typical moderate cyclist cadence is 40-60 rpm, that means your prop is turning 1000-1500 rpm....not slow. A "slow rotation" HPV propeller for water vehicles is 0.9m in diameter and turning about 180 rpm.
     
    DogCavalry likes this.
  3. Rodrigo Alves
    Joined: Jan 2023
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    Location: Sao Paulo - Brasil

    Rodrigo Alves New Member

    Entendi! muito obrigado vou fazer testes e vou postando aqui
     
  4. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    Translated:
    "I understood! Thank you very much, I will test it and post it here."

    6 or 7 to one usually works better for HPV prop / pedal ratios.
    A large diameter model airplane prop with matching pitch (0.6m x 0.6m) may prove helpful.
    Adjustable pitch props are available (Germany).
     
  5. portacruise
    Joined: Jun 2009
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    Location: USA

    portacruise Senior Member


  6. Rodrigo Alves
    Joined: Jan 2023
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    Location: Sao Paulo - Brasil

    Rodrigo Alves New Member

    Thanks
     
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