Kohler catamaran Duo480 Jigsaw

Discussion in 'Multihulls' started by Banzai, Feb 23, 2015.

  1. Banzai
    Joined: Aug 2014
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    Location: New Zealand

    Banzai Junior Member

    Hi , just launched the above in Auckland New Zealand for the first time despite being finished for months, waiting on sails, trailer etc.

    It is a 4.8 metre trailable cat from Bernd Kohler , France, (these days)

    Beam: just under 2.5 metres

    Weight: around 220kg empty

    Construction: West epoxy/200gm glass over Gaboon 6 and 9 mm ply.Exterior painted with Hempel 2 pot, interior triple coated West epoxy

    Rig: bi plane, twin 6.3 metre CF masts with nylon bearings which get inserted into CF mast holder/tubes
    Sails: twin 8.5 m2 diagonal battens which furl around the mast (like a furling jib) , designed and set up as boomless at present, but room to add light booms if I want. The boomless idea is all about simplicity and easy furling

    Cabin: small cabin, enough for two to overnight in, tons of storage inside as well

    This design has only been out since early 2012 so not many built, certainly no others in New Zealand. One builder in Europe has reported top speeds of nearly 15 knots, but it is about being a small trailable cruiser for me, not for terrifying my wife and grandkids. Only light wind sailing on first sailing day

    cheers
    Banzai
     

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  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Duo 480 Jigsaw

    Welcome to the forum and congratulations! Hope you and your family have a blast!
     
  3. nzclipper
    Joined: Mar 2011
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    Location: Auckland

    nzclipper Junior Member

    Cute little thing. Is that GregW I see standing there?
     
  4. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    Does this boat have the "anti vortex winglets" to prevent leeway ?

    If so, do you think they are seriously effective ?
     
  5. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    Oh, congratulations, looks neat !
     
  6. Banzai
    Joined: Aug 2014
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    Location: New Zealand

    Banzai Junior Member

    Hi

    indeed , that is the one and only GW in the photos. in fact i blame him for me getting myself into all this in the first place

    Re anti vortex winglets etc: no, forgot to mention this boat is one of Bernd's asymmetric hull models. No boards. Actually goes to windward pretty well considering.

    cheers
     
  7. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    From what I see many of his bigger asymmetric hulls use them, it would be interesting to measure your sailing angles and then add some. His pdf gives you the dimensions.

    http://www.ikarus342000.com/Antivortexp.pdf

    There has always been a lot of conjecture on the forums as to wether they work or not. Maybe you could use your craft to shed some light ?
     
  8. Banzai
    Joined: Aug 2014
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    Location: New Zealand

    Banzai Junior Member

    hi Redreuben

    I am not sure whether you caught my thread above , but my boat doesnt have the anti vortex panels. I wasnt intending to add them, so I wasnt quite sure what you mean.

    the Kohler designs are a mixture when it comes to leeway prevention. All the asymmetric smaller beach cats only use the hull shape to resist lee way. The slightly larger cats around 6 to 8 metres , if asymmetric, have nothing else either. Those with symmetric hulls have boards.

    In the bigger boats, models such as Bernd's original personal boat (pelican) and the newer KD860 use the antivortex panels, although these are symmetric hulls.
    There are some newer larger models , also symmetric , that use boards.

    So correct me if Im wrong , but, none of the asymmetric models have the anti vortex panels, or boards as far as I can see. What models were you thinking of? I have the study plans for many of them, or I could check with Bernd directly for you if there was some doubt.

    cheers
     
  9. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    My mistake, I thought the panels were part of the asymmetrical "system" but no they are only on the symmetrical hulls. Now, if only I could remember where I lived ! ;)
     
  10. Banzai
    Joined: Aug 2014
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    Location: New Zealand

    Banzai Junior Member

    no worries
    (NFW as some locals here put it)
     
  11. jamez
    Joined: Feb 2007
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    Location: Auckland, New Zealand

    jamez Senior Member

    Nice boat Banzyan and one of the best ply builds I've seen - the attention to detail is top notch. I think the extra resources spent on the rig/sails will pay off and she'll sail/handle well. looking forward to seeing a sailing report when there is a steady breeze :).
     
  12. aussiebushman
    Joined: Oct 2009
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    Location: Taralga NSW

    aussiebushman Innovator

    Congratulations Banzai - lovely job

    Alan
     
  13. Puddle Sailer
    Joined: Nov 2016
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    Location: Nassau Bay, Texas

    Puddle Sailer Puddle Sailor

    Newbie thinking of building this Cat or his ECO 5.5

    Howdy from the Texas Gulf Coast. I live by a huge, lengthy, very shallow cruising ground, the Gulf Inter Coastal Waterway.

    So if you are still around and able to respond to my inquiry, I'd love to hear an update on your Duo480, how she's done, and what you've learned about her. I'd also love to hear about the building experience you had, if you have time and inclination. Thanks, in advance, for any assistance you can lend.

    Thanks again,
    Jim B. Puddle Sailer
     
  14. Banzai
    Joined: Aug 2014
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    Location: New Zealand

    Banzai Junior Member

    Hi Jim

    yes, still around. We've covered a lot of ground since the above posting. The bi plane rig is nice, with the easy furling on the masts . I have stuck with the boomless set up for this reason. The only time I miss not having booms is on a reach in light weather, although even then I can pole the sails out with telescopic boat hooks. When it is windy, a deep reach is fine with the boomless set up as I sheet the windward sail over to the leeward side and form a kind of foil shape between the two sails. There is a point at a flat reach where there is a dead spot, which means hardening up a bit for a while, and then going a lot deeper for a while to compensate. That's about the only drawback, and since it is not a race boat, it is not an issue. Hard on the wind, or eased slightly is great to sail. When it is windy we get along nicely around the 10 to 11 knot speed range, with the best speed to date being a little over 12.5 knots. The boat feels very stable with its two shorter masts, compared to one single taller one. It has taken a while to fully get the hang of the twin rig.

    Construction wise, I was probably a bit slow. A couple of builders in Europe built theirs in 6 months or so. The hulls of the Duo 480 are quick to get together with the 3 main panels assembled with the bulkheads without a conventional building frame. The cabin is then much like any other to build, plus the companionway hatch, front nets, cockpit details, and rudder all adding to the overall time. There is an Eco 5.5 under construction near me and I have visited and kept in touch so that has been an interesting comparison. The Eco is a bit bigger, has dagger board(s), and has a multi chine construction, so, all in all, a bit more work. But the Eco will probably go up wind more efficiently than me, and will most likely be a bit quicker in light weather, with the extra waterline length. The Eco probably needs to have a wider beam than the legal towing limit (2.5 metres here in NZ) to get the utmost out of it, so that is a consideration too. The Eco being built locally is 2.5 metres for the towing compliance.

    The general build experience was enjoyable. Bernd was a pleasure to work with. The plans are fine, but with the building instruction booklet there were a few times I was scratching my head. You have to understand that Bernd, despite being very multi lingual does not have English as a first language so sometimes a bit of interpretation is needed. But at least there ARE building instructions unlike some, which come with the plans and drawings and little else.

    Hope this helps. There has been a bit of discussion about the model on Duckworks FB lately which I have kept out of since I am doing a review of the boat with another online publication.
    cheers
     

  15. Richard Woods
    Joined: Jun 2006
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    Richard Woods Woods Designs

    All boats sail well by themselves. Have you sailed against any other boats (monohull or multihull) to compare your boat with theirs?

    RW
     
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