General Boating Questions

Posted by Randi Bimeal on October 2, 2014 at 1:24pm

Hi All,

Well, it seems we are having a hard time locating a jetdrive to move our boat. The 2 we have found would be shipped from UK and Germany and we need it ASAP. We have 10 weeks to finish this project.

We are also having some troubles specing out a motor for the size of our boat. The boat dimensions are approximantly 3 feet long, by 1 foot wide by 1.5 feet tall.

Any help on either issued would be helpful. We need to make a decision tonight whether we are going to continue to find a jetdrive or move on to a prop.

Thanks,

Randi

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Tags: boat, jetdrive, motor, prop, size, spec
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Replies

  • Admin
    Thomas J Coyle III October 8, 2014 at 6:28pm

    Hi Randi,

    I received a notice that the Traxxas site is having technical difficulties at the moment, so try again later.

    The brushless motor and the Electronic Speed Controller (ESC) are cooled by running water from a pickup on the rudder support and flows through fuel line tubing through a heat exchanger on the ESC, from there to a cooling jacket that is wrapped around the motor and then dumped overboard.

    At 15-20 pounds, you are either going to need a very big brushless motor and propeller or a model nitro engine.

    If you chose to go electric, you are going to need a fairly large battery pack to obtain the endurance that you have specified.

    Regards,

    TCIII AVD

  • Admin
    Thomas J Coyle III October 2, 2014 at 4:02pm

    Hi Randi,

    I buy all of my marine propulsion systems off of eBay. The prices are right and the shipping is usually pretty fast.

    As I have mentioned below, the Spartan propulsion system will give you an idea of the bare minimum propulsion system required for your hull.

    You are definitely going to need water cooling for the brushless motor and Electronic Speed Control (ESC), and a servo/rudder/cooling water pickup.

    I suggest using a flex shaft/stuffing tube and collet motor coupling to turn the propeller.

    Your battery capacity will depend on how long the boat is underway and the expected cruise speed. Also the hull weight will be a consideration.

    Regards,

    TCIII AVD

  • Admin
    Thomas J Coyle III October 2, 2014 at 3:57pm

    Hi Randi,

    The Traxxas Spartan R/C boat is similar in length to your boat and uses a brushless propeller drive and servo controlled rudder: Link However, your boat is somewhat wider and a lot taller than the Spartan. At least the Spartan's propulsion system will give you an idea of the bare minimum required for a hull the size that you plan to use.

    Regards,

    TCIII AVD

    • David Boulanger > Thomas J Coyle III October 2, 2014 at 5:02pm

      Randi,  Is this a displacement hull or planning?  What's the weight?  It doesn't take much to move a displacement hull slowly. Just about any system will move the boat and Tom is probably correct in that the Spartan's system will give you an idea of what you need at the bare minimum.

       

      Regards

      David R. Boulanger

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