Pedal Powered Boats

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

  1. I57
    Joined: Feb 2008
    Posts: 172
    Likes: 6, Points: 0, Legacy Rep: 62
    Location: Melbourne, Australia

    I57 Senior Member

    On the Bay

    Got out on the bay today, boat going great. Went from Patterson River and tried out my new toy, a waterproof digital camera. Weather was great and what is very useful is an online camera that JV Marine has mounted near the river mouth.
    Link is http://www.jvmarine.com.au/index.php?page=live-bay-cam
    gives a pic loooking NW and gives wind speed and direction.
    Have mounted a new prop of 400mm dia that gives me a higher cadence and is less strain on my knees. Did a few timed runs at the rowing course and averaged 7min/km (8.5 kmh) and got up to 6m21s (9.5kmh) on a shorter run.
    Video is at wave top level, might find it interesting.

    Ian
     

    Attached Files:

    • bay.mpg
      bay.mpg
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  2. Guest625101138

    Guest625101138 Previous Member

    Ian
    I have a left over length of unused 8mm spring steel about 6ft long. I think it is long enough for your curved section. The previous piece you are now using had some distance on it and I am not sure how long it will last. I am a bit concerned you will lose your prop if you continue to use it without a strut.

    A new length should give you a few hundred hours at least.

    If you can arrange a time and place to meet I can give it to you. It is too short for my shaft because I do not use an extension tube.

    Rick W
     
  3. I57
    Joined: Feb 2008
    Posts: 172
    Likes: 6, Points: 0, Legacy Rep: 62
    Location: Melbourne, Australia

    I57 Senior Member

    Spring steel

    Rick
    Thanks for the offer of the spring steel, I can be at Lysterfield this Saturday afternoon if that suits.

    Ian
     
  4. Guest625101138

    Guest625101138 Previous Member

    Ian
    I should be able to make it. I am going up there tomorrow if it is not raining.

    Rick
     
  5. portacruise
    Joined: Jun 2009
    Posts: 1,120
    Likes: 32, Points: 48, Legacy Rep: 218
    Location: USA

    portacruise Senior Member

    magnet gears for pedal boat?

    Rick, thanks for posting about the magnet gearing:

    http://www.mgt.com.au/index.php?pageId=7080

    One of the most clever things I have seen around. Do you think the tradeoffs would produce a net positive for MGT++ compared to a sealed gearbox in HPB?

    Thanks.

    Vic

    PS. Good to hear your folding prop is holding up well.

    Porta
     
  6. Guest625101138

    Guest625101138 Previous Member

    Vic
    The fellow who pointed these units out to me is from TEA. They supply my gearboxes here in Australia. He suggested I take a look at these couplings. I have not priced them. The torque capability of the smallest ones would be marginal for a pedal boat.

    One advantage is the exact torque limit without anything breaking. It would be good protection for a prop.

    I expect they would be slightly more efficient but would take a bit of machining to mount up.

    Rick
     
  7. Guest625101138

    Guest625101138 Previous Member

    Greg K is about to depart for his shakedown cruise around Vancouver Island.

    The boat is nicely finished now per attached image although a few lose ends still. Also some unplanned testing in the local lake as well as a run-in with a garbage truck.

    Will be interesting to watch his progress:
    http://adventuresofgreg.com/blog/

    Rick
     

    Attached Files:

  8. Submarine Tom

    Submarine Tom Previous Member

    Rick,

    Greg's testing ground in Calgary is Glenmore Reservoir where I learned to

    sail as a young boy. Now, he's coming to Vancouver Island where I've

    earned a living on the water for almost 20 years now.

    Small world isn't it.

    I'll be watching his progress here.

    Tom
     
  9. Guest625101138

    Guest625101138 Previous Member

    Tom
    He has some information about the trip on his blog. From memory he will be going from north to south on the inside passage to give time to get used to the boat in somewhat sheltered water and then head north on the outside. Hopefully making good use of prevailing winds. The boat should surf well.

    The boat was designed for Greg's 150lb but his "ballast" and advisor, Jordan, is a really big guy, 6' 5" tall and about 200lb. They were tossing up whether to fit a larger keel bulb to enable Jordan to move around more freely but I think they are sticking with the current weight.

    It will be an interesting test because Jordan has experience in ocean rowing and I am keen to get his comparison between the two types of craft.

    Rick W
     
  10. Guest625101138

    Guest625101138 Previous Member

    Ian
    I have attached the GPS data from our circuits on the lake on Saturday.

    Rick
     

    Attached Files:

  11. I57
    Joined: Feb 2008
    Posts: 172
    Likes: 6, Points: 0, Legacy Rep: 62
    Location: Melbourne, Australia

    I57 Senior Member

    Lake

    Rick
    Its always interesting to see yourself, I didn't realize just how far back I lean in the seat. Comparing pic with your boat I need to sit up a bit more, might be why my back got so sore.
    Still don't know whether to fit a skeg or not, despite the amount of weed wrapped around the hub it wasn't that noticeable. With my old boat I slowed down a huge amount as the weed got tangled around the skeg. Without a skeg the weed wraps around the hub and trails behind leaving the prop free to spin, maybe thats the answer to the weed problem?

    Ian
     

    Attached Files:

  12. Guest625101138

    Guest625101138 Previous Member

    Ian
    I didn't think your recumbent position looked too severe. I have seen much lower on bikes.

    If you fit the new shaft and avoid it rusting I expect it will give you at least a couple of years. May last forever. You need to take care going astern.

    My concern with the existing one is that I cannot remember what it has done. I think at least the MM.

    Rick
     
  13. Dennis A
    Joined: Aug 2009
    Posts: 40
    Likes: 2, Points: 0, Legacy Rep: 47
    Location: Amersham bucks uk

    Dennis A Junior Member

    Greg K-Pedal Boat

    In Gregs block, the fact sheet shows a small wind turbine. As this generates axial thrust would this not invalidate any pedal boat record due to wind assistance.

    Dennis
     
  14. Guest625101138

    Guest625101138 Previous Member

    I do not know if there are any specific rules. The turbine is a back-up for the solar panels if they do not produce enough energy. In a head wind the turbine would be a distinct disadvantage. It is stowed unless needed.

    When you look at the amount of solar collection it is not a lot different to the 100W or so to propel the boat. The most important requirement for the power is water making. If you get down to quibbling over these aspects then surely human power should be used to produce the water.

    Actually it was even debated if the hatches should slide or tilt upwards. The tilting hatches would make better sails of course but they would offer drag in a head wind. Just standing up in a good tail wind will give 2 to 3kph.

    Right now they are not going anywhere because a shear pin in the drive has failed and needs repair. Not sure of the cause at this stage but Mitrpak are involved. The lower box was kept small as possible to reduce drag so it might be too small.

    Rick
     

  15. portacruise
    Joined: Jun 2009
    Posts: 1,120
    Likes: 32, Points: 48, Legacy Rep: 218
    Location: USA

    portacruise Senior Member

    Ian, I also do not use a skeg on my much lower electric power flex shaft. Weed accumulates as shown in your picture when I'm around weeds. There is a noticeable drop in thrust as additional weed accumulates adding to the ball of weed on the hub, until the losses drain too much power to make good progress. But that may not be your situation, as you may have less weed to deal with or it may have thinner stems that just break off at some point. If that is the case, you might already have a solution for the type of boating that you do.

    I can usually get rid of weed in a few seconds simply by lifting the prop into the air where it is flung off when the rotation speed increases. Sometimes just turning off power or reversing thrust for a few seconds while the prop is submerged clears the prop. In heavier weed, or shallow water, I can also tilt the angle up and run the prop in surface piercing mode to almost completely prevent weed accumulation as needed. I am lucky in that the whole system has held up for over a decade of frequent use to flexing, hitting rocks and even motor stall with tangled branches. A folding prop would be ideal for shedding weed if you do not use a skeg, as there would be nothing for the accumulated weed to hold to when power is cut and you coast forward.

    As indicated in a previous post, I am toying an auger system mounted to the shaft that might help keep surface weed from being dragged into the prop as the boat moves forward.

    Hope this helps.

    Porta


     
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