Duck Punt - with a twist

Discussion in 'Boat Design' started by Jeremy Harris, Mar 29, 2012.

  1. Submarine Tom

    Submarine Tom Previous Member

    Yes, I've seen it.

    I thought you may like my idea, complete with air prop and torpedo like appendage.

    Right up your alley...

    Like I said, too bad I can't go. Although, they may not accept my idea.

    Could be that a SWATH would work better with a drill in each hull and skip the air pumping idea.

    How's the build coming?

    Shame about your entry last year. I hope he bought you a beer or two!
  2. Submarine Tom

    Submarine Tom Previous Member

    Your great idea got me thinking Jeremy!

    Pivoting aft pod, individually sensored foils (four) using Bradfield style wands, centre struts.

    They could even be contra-rotating using reverse on one drill.

    You can see I've got too much time on my hands.

    Attached Files:

  3. messabout
    Joined: Jan 2006
    Posts: 3,217
    Likes: 369, Points: 83, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Now look at what you have done Jeremy. After watching the video of those crazies in their portable tool boats, I'll just be forced to build one. That looks like too much fun to ignore.

    My first thought is to drive the boat with a 19.2 volt drill. (Sears Craftsman ....there are two of them in my shop) There is also a few sheets of 4mm Okumee that has been calling me.

    There is a boat in the video who has gone the simple route with a dragon tail scheme, the shaft housing lies in a transom yoke. That looks easy enough and very simple too. Good enough for my first try.

    This madness may cause me to be put in jail. Florida boating regulations require that any boat with any kind of motor must be registered and have a fee paid. Canoes with trolling motors included. The boat is required to have a presumed authority (Florida fish and wildlife official) certify that it is a functional boat with all kinds of gear including fire extinguisher, throwable flotation device, wearable flotation devices, anchor and rode, registration numbers attached to both sides of the bow, and a whole bunch of other stuff. No way I'm going to carry all that in my electric drill boat. So if I land in the jail house it's the fault of a Brit wizard named Jeremy. I will try to exercise some forebearance and not make this into an international incident.
    1 person likes this.
  4. Jeremy Harris
    Joined: Jun 2009
    Posts: 978
    Likes: 59, Points: 28, Legacy Rep: 711
    Location: Salisbury, UK

    Jeremy Harris Senior Member

    Sorry for the lack of updates on this project. It got held up by the cold weather we had in April here, which pretty much stopped any epoxy work for a month or so. Anyway, I only have ten days or so till the competition this boat's being built for, so I've had to get a move on.

    The cheap foam core (10mm thick XPX foam flooring underlay) works well, although I should have gone an bought some decent 300 g/m² cloth rather than use the roll of rovings I had. The rovings are OK, but have made the hull a bit heavy from the need to use a fair bit of microballoons and resin to fill the weave and fair the hull up.

    I'm pleased with the stiffness and strength, though. I'd probably do things a bit differently next time, use a better mould frame with more support for the foam sheets, maybe even pre-laminate the sheets and then cut and join them like ply. Anyway, I'm just about done with filling and sanding, so here are a couple of shots of the hull almost ready for paint. The "outboard well" is for the cordless drill powered drive leg for the race, and will have a tight fitting internal cover to stop turbulence.

    Attached Files:

    2 people like this.
  5. hoytedow
    Joined: Sep 2009
    Posts: 5,849
    Likes: 392, Points: 93, Legacy Rep: 2489
    Location: Control Group

    hoytedow Carbon Based Life Form

    Nice work, Jeremy.
  6. troy2000
    Joined: Nov 2009
    Posts: 1,743
    Likes: 170, Points: 63, Legacy Rep: 2078
    Location: California

    troy2000 Senior Member

    OK, I'm officially impressed. Creative use of materials, and it's going to be a very pretty little boat.

    This site needs a 'thumb up' smilie....
  7. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 346, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    tool boat

    Such a great idea! Just discovered the thread-very cool-thanks......
  8. Jeremy Harris
    Joined: Jun 2009
    Posts: 978
    Likes: 59, Points: 28, Legacy Rep: 711
    Location: Salisbury, UK

    Jeremy Harris Senior Member

    Thanks for the kind words, folks.

    This was truly experimental construction, as I've not heard of anyone using cheap foam like this for small boats before. The biggest material cost was epoxy, but with the right type of glass cloth (a plain or maybe twill weave) I could have used a lot less resin (there's around 7 kg of resin in the boat, way too much for the weight of glass).

    Also, if I'd used peel ply, maybe with a sheet of plastic over it, and then squeegeed the hell out of it I could have got the glass/resin ratio a bit closer to 1:1. I didn't want to get involved in vacuum bagging etc, as I wanted to see if something simple could be built using methods pretty much anyone could use, with no special tools.

    For a knockabout, light weight, car toppable boat, the cheap foam core method has a fair bit to commend it. The hull foam (ignoring the buoyancy tanks I built in each end) give the boat around 40kg of buoyancy, so it will still float pretty high even when full of water. There's another 200kg or so buoyancy in either end, so there's little danger of it ever sinking, even if pretty well loaded.

    Once the race is over I'm going to play around with some ideas I have for a "sail". I've always wanted to try and build a Flettner rotor, as I've long thought that this would be the ideal type of sail for calm inland waters here. The plan is to make a rotor around 8ft to 9ft long and 15" to 18" in diameter, powered by a solar panel on the top plate. I'd add a small battery for back up. I'd then like to investigate adding automatic controls, so that the rotor speed and direction was controller by the relative wind speed and direction. I've been inspired by the work Stephen Thorp did with his rotor powered sailign dinghy (see this old thread:
  9. philSweet
    Joined: May 2008
    Posts: 2,514
    Likes: 297, Points: 83, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member


    I was thinking a pedal powered Flettner rotor would be a decent option for the Everglades challenge/ Florida challenge depending on how they classed the boat. Could either pedal the prop or the rotor depending on conditions. Please report on the power requirements of the thing, because as I noted in the thread you referenced, every single report on Flettner rotors I could find was missing one crucial number making it impossible to actually design a system for maximum gain or size a rotor system for a hpv given probable weather.

    one other random thought-

    wouldn't a cordless saw be a better tool? They usually have a bigger amp draw and battery life would match race length better I would think.
  10. Boston

    Boston Previous Member

    My cordless saw eats batteries

    My cordless drill on the other hand seems to last forever.

    the sawsall is the one that kills the batteries in about a split second.
  11. lewisboats
    Joined: Oct 2002
    Posts: 2,329
    Likes: 129, Points: 0, Legacy Rep: 1603
    Location: Iowa

    lewisboats Obsessed Member

    My grinder cooks batteries...they literally get too hot to charge and have to cool down first.
  12. tunnels

    tunnels Previous Member

    i love it !! you made my day !

    Innovation !!:D:)
  13. Jeremy Harris
    Joined: Jun 2009
    Posts: 978
    Likes: 59, Points: 28, Legacy Rep: 711
    Location: Salisbury, UK

    Jeremy Harris Senior Member

    To be honest, I just used the biggest cordless tool I happened to have, which is that drill. The race isn't over a very long distance, it's an out and back course with a right angle dog leg and a 180 deg turn around a buoy at the furthest point. It's run as a knockout competition, in heats, with two boats at a time competing. Turning capability is fairly important, as the boat ahead at the first turn buoy has the right under the rules to turn across his opponent. Turning as tightly as possible around the 180 turn is also a big time saver. Here's a video of last years event, unfortunately my entry was damaged by a spectator before the race so I didn't start:
  14. Boston

    Boston Previous Member

    So I found that pink foam stuff at the hardware store today, some kinda Styrofoam. had a plastic coating on either side and looked like it had a grain as you described. $17 a sheet for the 1/2 inch stuff. That sound about right ? outdoor grade water resistant. I didn't see it saying anything about underlayment.

    Might try it on my model. assuming with that plastic coating it takes glue ok

  15. Jeremy Harris
    Joined: Jun 2009
    Posts: 978
    Likes: 59, Points: 28, Legacy Rep: 711
    Location: Salisbury, UK

    Jeremy Harris Senior Member

    The stuff I used didn't have a coating on it, but was slightly rough on both sides. I got it here in the UK from these people: and used the 10mm thick stuff. I found they sold it a fair bit cheaper on ebay:

    The same stuff is probably available from underfloor heating suppliers elsewhere in the world, I'd have thought, as the stuff I have actually originated in China, based on the stuff on the boxes.

    The stuff you describe sounds similar, but I'd be a bit concerned about that coating. Maybe you could gently rough it up a bit?
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.