Pedal Powered Boats

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

  1. Guest625101138

    Guest625101138 Previous Member

    Mike
    I would like the hst file from one of your races if you have it. I have been loading into Excel for analysis. I can do that with your data.

    I will leave the running data for now. I think the GPS is set up for a bike so does not do all that well for running.

    I went through one of your recent blogs showing a blue decked, black hull that you said used a Hobie flapper drive. I would be interested in any information you have on the boat. I saw that it finished well behind you and I was wondering if the boat met the builder's expectations. Hobie have done a tremendous job on over-selling the efficiency of their drive and I expect buyers would be disappointed when put alongside more efficient systems.
     
  2. Guest625101138

    Guest625101138 Previous Member

    Mike
    This is from the Hydrocycle web site:
    http://www.hydrocycles.com/pedalos.php
    The Pedalos is spoken of as going into production. It is also claimed to be the fastest production PPB as Beppe pointed out.
     
  3. MLampi
    Joined: Aug 2008
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    Location: Bellevue, WA

    MLampi Junior Member

    Perhaps I'm being picky, but if there is only a single one of these boats in existence, and the maker has not made more than one, then I claim that the thing is not truly a "production" boat.

    Michael Lampi
     
  4. MLampi
    Joined: Aug 2008
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    Location: Bellevue, WA

    MLampi Junior Member

    I've looked through the SportTracks and the Garmin Training Center (GTC) programs and neither appear to offer hst file output. The GTC has tcx files only. Are those what you want?

    As far as I can tell the GPS has three main modes: running, cycling and other. The running mode seems reasonably accurate, but I guess your mileage may vary (pun intended).

    I never saw that blue/black Mirage driven boat since that race in February. There have been a number of races in areas to the north of that venue since then, as well as quite far to the south and southwest, but that boat never appeared again.

    In about two weeks there will be a fairly major race not far from downtown Seattle that crosses Puget Sound that has historically been a popular one for unique boats to appear in. Perhaps it will show up again.

    Michael Lampi
     
  5. beppe
    Joined: Jul 2008
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    Location: Udine, Italy

    beppe Junior Member

    Hobie Mirage, a great opportunity...

    here
    you can find a nice explaination about why the performance of the Mirage drive is superior to that of a propeller drive system,

    http://www.hobiecat.com/kayaking/miragedrive.html

    but no hard data... ;-) hehe

    I believe that the success of the Mirage is not a threat, but a great opportunity for PPBs... it creates a potential market for higher efficiency PPBs as you point out.
    A different way of thinking is needed to exploit this opportunity, possibly embracing a more collaborative view; the Open Waterbike Project is of course just an attempt to do that...
    The future belongs to those who can imagine it...

    Beppe
     
  6. Guest625101138

    Guest625101138 Previous Member

    Beppe
    I have hard data. At energetic continuous effort the flappers achieve around 35% efficiency. For a full effort sprint the efficiency lifts to just over 50%.

    The site you point to is just marketing hype - it is drivel from any engineering perspective.

    Some interesting comparisons here for full effort 100m sprints:
    http://www.humanpoweredboats.com/HydroFest/2001/HydroFest2001Results.htm
    Considering power is roughly a cube function of speed you can imagine the sort of engine needed to get a Hobie from 10kph to the 18kph achieved with the WaveBike.

    Like I say Hobie have done a great marketing job and reasonable engineering on the flapper system but all statements about efficiency are nonsense.
     
  7. Guest625101138

    Guest625101138 Previous Member

    Mike
    The hst file is a history file you export. So it is on the file menu. If you have kept all your data it will be very large. However I think you can just export one session.
     
  8. beppe
    Joined: Jul 2008
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    Location: Udine, Italy

    beppe Junior Member

    mirage vs. wavebike

    Rick, I have no hard data about the Mirage, but I believe you are right.
    Though, I believe we should focus on long distance performance, not on sprint peaks. Say 10 to 14 KpH, this is enough...
    I exchanged a few emails with George Tatum at the beginning of the Wavebike endeavour, the boat was innovative (even if the concept had been tried years before at Oxford University, if I remember well) and George was very focused and enthusiastic. I was working on a more traditional concept at the time, we talked about the possibility of importing Wavebikes to Europe.
    We all know the following story of that beautiful innovative PPB.
    The Mirage, on the other hand, is successful, but we suspect we can do better. Should we try the same George (and many others, remember the Sea Saber?) tried?
    I'd say a different approach is needed here. If it will be The Open Waterbike' I can't say for sure, I certainly hope so. What I'm sure of, is that the old way spells disaster...
    Beppe
     
  9. beppe
    Joined: Jul 2008
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    Location: Udine, Italy

    beppe Junior Member

    The Open Architecture Pedal Powered Boat

    you may have noticed that I try to use a different terminology since this comment of yours.

    The correct term could be The Open Modular Architecture High Efficiency Pedal Powered Boat -in fact this is what the so-called Open Waterbike Project is focused on, a collective effort aimed at building a PPB based on an Open Modular Architecture.

    We could call it The Open Pedal Powered Boat for short.
    We can use these precise terminology in this technical forum, but I must admit that is doesn't seem so fashionable for the general public.
    I'll ask the Open Waterbike community members, it's up to them to decide, but I believe we need something better than Open PPB.
    Has anybody a better idea?

    I'll be on holiday next week, and I hope than the sight of people boring themself do death on mediterranean beaches, badly needing our PPBs, will inspire me something...

    Beppe
     
  10. Guest625101138

    Guest625101138 Previous Member

    Beppe
    The Hobie Adventure drive achieved 5.3mph with input of 180W to give calculated drive efficiency of 38%.

    Same power on the V11 boat gives 8mph with overall drive efficiency of 84%.

    So the sprint speed relativity translates well to performance at a more relaxed pace.
     
  11. MLampi
    Joined: Aug 2008
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    Location: Bellevue, WA

    MLampi Junior Member

    There is mention of a history file on the export menu. However, it only seems to output files with a .tcx extension.
     
  12. beppe
    Joined: Jul 2008
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    Location: Udine, Italy

    beppe Junior Member

    hobie vs. open?

    This is very intesting!
    Are there data accepted officially by Hobie? If not, are they reliable?

    The Open Pedal Powered Boat requirements (http://www.openwaterbike.com/architecture )

    are:

    "Intended users range from amateurs to athletes (design total mechanical power output about 150 to 400 W and up to 1,000 W in sprints).

    Particular users should be able to make good progress with as little as 50W"

    and I believe that we need data in this range of mechanical output power.
    Even more important for commercial purpouses the performance of double seaters.

    This gives also an answer to a previously debated question: any boat significantly more efficient then the Hobie could have a great market opportunity because the market is opened up by the Hobie itself and there is always people wanting more performance and willing to pay for them.
    But the offer should be global, and this is beyond the possibility of very small firms. This is a key point of my project...

    Beppe
     
  13. Guest625101138

    Guest625101138 Previous Member

    I doubt that Hobie have any interest. As long as they sell boats that is all that concerns them. And the data is considerably more accurate than any performance information published by Hobie.
     
  14. Guest625101138

    Guest625101138 Previous Member

    Mike
    I have attached a screen image of producing the hst file from my Garmin software.
     

    Attached Files:


  15. alexlebrit
    Joined: Aug 2006
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    Location: France - Bourbriac

    alexlebrit Senior Member

    Dare I say it but isn't one of the reasons the Hobie set-up is so successful the fact that they were in the business for quite a while before they ventured into PPBs, they have an extensive dealer network and have plenty of cash to spend on marketing. Add in the fact the drive's small, easy to use and easy to remove and that once removed the boat is still usable and you end up with a versatile, if not hugely efficient, machine.

    Purely from a saleability standpoint it looks to me like Hobie have it just right.

    PS, Is it just me or does the Mirage drive in motion remind you of a sea-turtle?
     
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