Pedal Power - assistance needed

Discussion in 'Boat Design' started by Casey, Sep 6, 2010.

  1. Casey
    Joined: Sep 2010
    Posts: 3
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    Location: Thunder Bay, Canada

    Casey New Member

    Hello all..

    I am new here, and hopefully going to be new to the world of pedal-boating.

    I have a couple of "naive" questions to ask before beginning. I must also state that I have very little woodworking experience (other than a cutting board I made 25 years ago in a shop class), and very little kayak experience - I am a canoeist and a cyclist, and would like to combine the two.

    I have researched many of the commercial boats, but would like to make my own (to save on cost as much as anything else). I like the look of the Cadence, but am not sure if it is big enough - I am looking to make this an expedition boat for use on Lake Superior - which as you know, has ocean-sized storms and waves, but less predictable.

    So, here are the two questions:

    1. I was looking at possibly building this: https://www.boatdesigns.com/20-Sea-Kayak-Two-SG-touring-kayak-for-two/products/185/ , or something like it, in a stitch-and-glue, perhaps even from the available kit, and fitting it with small outriggers. The option is to have a large opening for one, rather than for two. This should leave enough room for a drive unit and myself (6'1", 200 lbs), and it has a wide beam of 30". SO...
    How would I install a drive unit - again, Naive here - without water getting in the hole I make for the unit? I would likely try and get a hold of a manufactured drive unit, like the SpinFin if they are still made, or the other one from Michigan...but once I cut a hole in the bottom of the boat, how do I keep it from sinking? The drive unit would need to be able to be pulled out for maintaining, so it can not just be epoxied in...am I missing something?

    2. How would I decide where to place it? I need to be relatively centred, I assume, in the boat, but what about the drive unit? It would then be a little ahead of center, toward the bow? How do I know where to put my seat and the drive unit?

    Looking forward to this project, but am I taking on a lost cause here? Should I just buy a Cadence or a Nauticraft and be done with it?

    Looking for any guidance at all...
     
  2. Tiny Turnip
    Joined: Mar 2008
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    Location: Huddersfield, UK

    Tiny Turnip Senior Member

    Hi Casey
    Welcome.
    There is a wealth of information, nearly a thousand posts, on pedal powered boats on this thread:

    http://www.boatdesign.net/forums/boat-design/pedal-powered-boats-23345.html

    Rick Willoughby, the originator of the thread, and with huge expertise in the area, has sadly left the forum, but is contactable, and has his own pedal powered boat pages here:

    http://www.rickwill.bigpondhosting.com/

    As human powered boats are low power, the limiting factor in open water is usually windage; the more boat surface area there is out of the water, (acting as a sail) the lower will be the windspeed that is too powerful to pedal against. My own pedal boat, based on Dart 18 catamaran hulls, with little above them other than the two human engines, reaches my limits of confidence in about a F6 wind, 6-8ft waves, if not too steep, in inshore waters.

    Many pedal powered boats avoid penetrating the hull by having the drive over the side of the hull, or between two catamaran hulls.
    The forward aft positioning I suspect will largely be a question of correct centre of gravity for the centre of bouyancy of the hull, and best answered by someone with rather more competance in naval architecture than me!

    Google 'adventures of Greg' to find the boat that Rick W has designed for Greg Kolodziejzyk to 'pedal the ocean' in.
     
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  3. DougCim
    Joined: Jul 2010
    Posts: 40
    Likes: 3, Points: 0, Legacy Rep: 42
    Location: IL,USA

    DougCim Junior Member

    I want to build a small aluminum boat (possibly a pedal-powered) but won't get the time this year. It's just as well, I keep getting totally different "great ideas" every week or so.

    People who have converted canoes add a well for the drive motor to swing down into.

    As to how to keep big waves from coming in, sorry can't help there.
    Perhaps you really should think about a sit-on-top or a catamaran design. Consider this: the main advantage of sit-inside kayaks is that your hips are placed at the waterline, which makes normal paddling (with double-bladed paddles) easier, because you don't need to reach down so far to put the paddle blades into the water..... But if you've got a foot-pedal drive, you're not real likely to be hand-paddling the boat any great distance anyway, unless the foot-drive unit breaks.

    If you insist on a monohull, then it's a lot easier to make a seat that moves fore-aft than it is to make the drive unit well move fore-and-aft. Since you plan on outriggers, you could also make it possible to move the outriggers move fore-and-aft, to accommodate for any front-rear imbalance that your shifting seat results in.

    If you go with a catamaran design though, it is much easier to make the seat stationary and have the pedals/drive unit adjust instead.

    Would probably be easiest. Dunno about cheapest.

    I want to build my own, but am still very much undecided on an overall design. I have noticed that most people who build pedal-powered boats are making very lightweight, racing-type rigs and not anything very roomy or durable for leisure use.

    I bought my kayak first without a rudder, and then got one for it, so I used it both ways. I much prefer the additional control afforded by the rudder, especially in rougher weather/higher waves. So anything I build would either have the prop-drive unit directly on the rudder, or really close to it.

    Technically I don't like the Cadence and Nauticraft, because they transmit the power from one end of the boat to the other, just to have a rear-mounted prop. The prop is near the rudder so maneuverability is probably acceptable, but the boat ends up drafting a lot deeper than it really needs to, just to run the shaft under the occupant's seat. Rear-mounted props and rudders are a traditional layout of larger powerboats, but most of the reasons it is used in them don't exist in a small pedal-boat.

    But I don't quite like the layouts of the Hobie and Native pedal-kayaks either, because their drive units are static, in that they don't turn left-and-right. A drive unit mounted directly on the rudder would provide far greater maneuverability, but putting the rudder where the Hobie and Native boats have their drives wouldn't work well, as it's not on the end of the boat. Such a rudder+drive might work okay while using the pedal drive, but it wouldn't help much while using a regular paddle (assuming you ever had to).

    What I am thinking lately is that it would be best to use a drive unit mounted on a rudder, on the front end of the boat. This would allow a rudder that would work well while paddling normally, would provide the best maneuverability while using the pedal drive, and it still keeps the pedal-drive power transmission distance fairly short.

    I don't like any power-transmission methods I've seen so far though, and there's other decisions unmade as well. The rudder would need two means of control--since you would steer with your hands while pedaling, but steer with your feet while paddling....
    ~
     

  4. portacruise
    Joined: Jun 2009
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    Location: USA

    portacruise Senior Member

    Hope these comments help.

    Porta
     
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