Pedal Powered Boats

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

  1. Guest625101138

    Guest625101138 Previous Member

    Something like that 4HP racer will be my first solar boat. It is not intended for racing on the Murray. The stern was to take an outboard.

    Actually flat sterns cause squat not lift. They work on a planing hull by initially sinking the stern to get the bow-up trim for better lift in the mid sections.
  2. Guest625101138

    Guest625101138 Previous Member

    Greg K has been making steady progress up the inside passage of Vancouver Island on a shakedown trip. It has been interesting monitoring his track on his web site:
    There are 10 minute updates on the track and you can display the last two hours on the large map by clicking on the appropriate command button.

    He has had some interesting experience with the tidal flow trying to make the best of it when it is with him and hugging the shore to minimise impact when it is against him.
  3. Dennis A
    Joined: Aug 2009
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    Location: Amersham bucks uk

    Dennis A Junior Member

    Folding Weed Free Prop.

    Finished at last, this has a 406 dia. with a 610 pitch. the pivot slot is 6.5 wide and I had to open out the rest of the slot to 9.5 so that the twist of the blades would not jam up when folded.


    Attached Files:

    1 person likes this.
  4. portacruise
    Joined: Jun 2009
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    portacruise Senior Member

    Looks like really good work, thanks for the pictures, Ian. I can see how the blades remain partially deployed to get a bite into the water and swing out for an even balance. My RC props folded back much further than that, so the blades almost touched behind and sometimes wouldn't deploy evenly. But I am rigging a restrictor that should fix. Since the RC blades are much lighter, I may have to put a pinch of lead on the ends to increase the centripetal force...


  5. Guest625101138

    Guest625101138 Previous Member

    Looks good. It is a little simpler than mine having the single pivot.

    When will you be testing it.
  6. spidennis
    Joined: Feb 2007
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    Location: south padre island, texas

    spidennis Chief Sawdust Sweeper


    that is a thing of beauty, sheer artwork!
  7. I57
    Joined: Feb 2008
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    Location: Melbourne, Australia

    I57 Senior Member

    Pedal the Ocean

    Just read Greg K's trip report, 314km in 2.5 days is impressive. It would be an interesting to compare with the two guys who paddled across the Tasman in their double kayak. With them both had to be paddling to make progress and they were exposed to the elements. Greg and his mate stayed inside and just kept going, one on and one off never stopping.

  8. portacruise
    Joined: Jun 2009
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    Location: USA

    portacruise Senior Member

    folding prop

    Did a little more testing on my folding RC prop, solving the uneven prop blade deployment. The good news is that the the prop is much more rugged than I thought it would be, absorbing bottom hits without any apparent damage. Also, there is no tangling whatsoever in the prop blades themselves once power is stopped as everything drops off the blades in the folded position. Having to stop and clean fixed blades was sometimes a time consuming issue with fixed blades.

    The downside is that the flex shaft itself gathers and funnels weed strands downward to the prop spinner area where these weeds bunch up and cling to the shaft. Even powering the shaft in reverse does not clear weeds from the shaft unless it is done immediately before any kind of considerable buildup. Sensing early accumulation is almost impossible with a motor, but might be possible when pedalling. So I couldn't get much improvement on completely weed free performance. Powering the shaft in reverse loosens the accumulated clump on the shaft itself, but does not fling it clear like when it is on the fixed blades. Some removal by hand is still required, although it does go faster than when tangled in the fixed blades themselves.

    Hope this helps.


  9. Guest625101138

    Guest625101138 Previous Member

    Lot 41 was a dog of a boat. I reviewed the design after their initial testing and did performance estimates for a change they made after initial testing. With two paddling it can achieve the speed Greg gets by himself carrying a passenger or food for an ocean crossing.

    The hydrodynamic drag was only part of the problem. The bluff cabin presented huge windage from the forward direction so was good for sailing them backwards.

    The aim with Within was to have a boat that could make way in extreme conditions. He should be able to make progress in 60kt winds. Not fast but enough to get away from a dangerous shoreline.

    As it is the CTD guys made it across the Tasman and Greg has yet to do something of similar magnitude.

    Attached Files:

  10. Guest625101138

    Guest625101138 Previous Member

    Have you got any pictures of what you are using or links to where you got the prop?
  11. portacruise
    Joined: Jun 2009
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    portacruise Senior Member

    RC prop

    Rick, hope this link works:

    This is not really a very rugged prop, but the price was right, it was in stock and delivery was fast. I didn't want to waste money on a concept which might not work in springing for a higher quality to start with. I will try to get a picture of the shaft setup to your website and some links for better candidates in a few days.


  12. portacruise
    Joined: Jun 2009
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    Location: USA

    portacruise Senior Member

    Rc prop #2

    Oops, Try this one, specify 2 blade and folding then scroll down to 10X8 $19.99 USA. Hope this one works.

  13. Guest625101138

    Guest625101138 Previous Member

    I have attached a pic of the prop so others do not need to search for it.

    How much force do you think you could safely apply to the cone with the blades supported within 1" of the tips?

    There is also a 16.5X15 blade set that is getting closer to what would be useful on a pedal boat:

    Attached Files:

  14. Tomboi
    Joined: Feb 2010
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    Location: Oregon Coast

    Tomboi All tied up

    I've seen websites with the peddle kayaks, but don't know anyone who has one. I thought it would be neat to alternate between paddle/peddle, but doesn't the setup very much limit what the kayak can do?

  15. Guest625101138

    Guest625101138 Previous Member

    Hobie show people paddling and pedalling at the same time but it is a waste of effort. People who try it soon work this out.

    A recumbent seating position is very comfortable for long distance. It is much easier on the body than paddling, rowing or upright cycling. The pressure is spread between back and buttocks. Trying to paddle at the same time is awkward and energy sapping.

    If you want to try a nice pedal boat you could chase up Mike Lampi. He lives in Seattle so not too far from you:
    You should probably sit down before you ask the price of a Cadence though.

    One nice feature of powering with pedals is that the hands are free to eat, read, photograph, fish or whatever.

    If the pedal boat is well engineered it will just be a little heavier than a kayak but, operationally, it does not need to be much different. It takes some design effort to overcome issues with prop fouling if there is weed but there are ways to achieve this. The top speed of a pedal boat is quite a lot higher than a paddled boat for any individual and the sustainable speed is a little better with pedal power.
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