My next electric catamaran project

Discussion in 'Multihulls' started by SolGato, May 15, 2019.

  1. SolGato
    Joined: May 2019
    Posts: 32
    Likes: 13, Points: 8
    Location: Kauai

    SolGato Junior Member

    38AE0C97-E6FE-4244-9A6B-2AB5D9A0D455.jpeg A6DFC2B2-B90D-4191-BB6D-9153C0636A12.jpeg 182D6968-F3CC-4951-AC31-14A7AB064425.jpeg FC24FA5A-BCA1-4523-8CA7-66BB6D130BB3.jpeg 84CCA308-0FE4-4D90-9DBC-3F47537EACC6.jpeg I purchased this baby Cat (Kitten??) a few months back. Had fallen in love with it some years ago but missed out on purchasing it. When it resurfaced, I pulled the trigger.

    I was just about to buy a kayak or paddle board to use as a dinghy to get to my moored Trimaran when this popped back up for sale. The guy I bought it from fitted a high performance windsurf rig to it and also hung a 3HP outboard off the back for what he called the “James Bond” experience!

    Anyway, it’s basically a car top-able fiberglass catamaran built a lot like a Hobie but much nicer with a hard deck that features a center board slot, and then each hull has two fin boxes, one at the very rear and one at the rear beam area.

    I don’t know much about who made the boat or what it was originally designed for, but it sure is cool!

    I’m in the process of building a custom aluminum trailer for it that can disconnect and be pulled behind for beach launching. This boat will basically be a one person dinghy. I plan to add a forward trampoline for gear and will be adding electric motors for propulsion.

    Unfortunately brushless trolling motors like the ones I used on my Hobie conversion are too heavy and unnecessary for a boat this size and weight. Instead, I’ll be using a pair of brushless ROV motors. Believe it or not, these little ROV motors from BlueRobotics put out 11lbs of thrust at 3800RPM’s @ 16V putting out 350W of power, while weighing less than 1lbs each! The company makes a nice little 2 channel PWM controller so you can drive up to 4 of these motors in independent pairs or all together with differential control, even add servo remote control to operate them. The company is developing an even larger thrust motor that I will eventually move up to, but for now these little guys will be used for proof of concept.

    In order to test ideal motor location, I will be installing a section of aluminum T-slot track to the bottom of each hull running from fin box to fin box using the boxes to anchor the section so I don’t have to drill any holes. This will allow me to play with the positioning of the motors along the length of the track and compensate for future upgrades that might shift the weight and attitude of the boat like a hard bimini with solar for example.

    Anyway, now that my bigger HobieCat conversion SolGato is on the water and working well, I’ll be focusing some time on this little guy.
     
    Dejay likes this.
  2. BlueBell
    Joined: May 2017
    Posts: 750
    Likes: 76, Points: 28
    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    YOU are a total nut-bar and I love it.

    Differential steering?

    A full solar canopy would be sweet but no batteries.
    They're heavy, expensive and a pain!
    Okay, one tiny one.
     
  3. SolGato
    Joined: May 2019
    Posts: 32
    Likes: 13, Points: 8
    Location: Kauai

    SolGato Junior Member

    Yes, on this build everything is getting scaled back so battery will be E-Bike LiPo (running directly off solar is too hard on digital PWM controllers), hardtop will have 2-300W flexible solar with a single MPPT with differential steering via wired remote.

    I think for fun later down the line, I’ll add servo radio control to it since the motors and controller are already setup to accept it, that way I can remotely run it to shore to pick up and shuttle guests back out to my Tri, which would be good nuts, and not bad nuts as hanging a 3HP off the back and sitting in front of it in a plastic fishing seat screwed down with nothing but wood screws! Glad to have rescued it before anyone got hurt.
     
  4. BlueBell
    Joined: May 2017
    Posts: 750
    Likes: 76, Points: 28
    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    How much do you weigh?
     
  5. SolGato
    Joined: May 2019
    Posts: 32
    Likes: 13, Points: 8
    Location: Kauai

    SolGato Junior Member

    I weigh 185lbs, prob be 200lbs by the time I get the boat built if they don’t move the donut case from the main entrance of my local grocery store!

    This little catamaran is 12’ long with about a 4.5’ beam with hulls that are about same volume diameter as a Hobie14, but it is laid up quite a bit lighter with reinforcement where it’s needed compared to H14 hulls. The arch in the deck really make the boat strong and the hull skins are more like a kayak than a Hobie.

    cat project.jpg

    The previous owner weighed 200+ and had an old 3HP on the back, so I know it can handle some weight. He also had a trolling motor on it but wanted to get it up on step which is why he swapped for the 3HP IC outboard. I think the deck acts a bit like a tunnel hull. He believed the boat was designed to be a performance windsurfer, but the centerboard slot along with the fin boxes makes me think it was setup for a sail rig at one point as well. He added the blocks at the rear transom to hang a dual rudder tiller stick setup from, so it’s a bit of a mystery as to what it was designed for originally. I can tell you however that the construction is very good with a lot of detail and care spend laying it up. Even has foam inside with access hatches.

    Here’s a photo of it with the windsurf rig.
     
  6. BlueBell
    Joined: May 2017
    Posts: 750
    Likes: 76, Points: 28
    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    Same as me but I'm already 200!

    Cool photo, thanks.
     
    SolGato likes this.
  7. Dejay
    Joined: Mar 2018
    Posts: 331
    Likes: 45, Points: 28
    Location: Europe

    Dejay Senior Newbie

    That's awesome too :) Thanks for sharing your projects!

    I'd be curious about the efficiency of those motors / propellers. Probably doesn't matter that much though. BlueRobotics has quite a lot of cool gadgets!
     
  8. SolGato
    Joined: May 2019
    Posts: 32
    Likes: 13, Points: 8
    Location: Kauai

    SolGato Junior Member

    Thanks! Ya, they look to be pretty efficient and they are brushless with PWM control, but with the additional of solar and the type of use this boat will see (short trips to and from shore) it shouldn’t matter too much. The new motors they are developing are supposed to be more than 2X thrust of these N200’s and should work with the Command Controller, I’ll just have to build a bigger battery with a bit more voltage and capacity to support them.
     

  9. coolmike
    Joined: Oct 2011
    Posts: 1
    Likes: 1, Points: 1, Legacy Rep: 10
    Location: China

    coolmike Engineering and Design

    Looks good
     
    SolGato likes this.
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