My Jet Jam Brushless Project

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  • FLMIBrewer
    Junior Member
    • Apr 2016
    • 16

    #1

    My Jet Jam Brushless Project

    Not a bad start for initial setup. Its definitely to hot a setup on 3s for long wot runs but for the rapid running I do, it's pretty good. The current speed where I run keeps me mid throttle mostly. Current motor is a 2212 stator, 9 pole, 6 slot i believe. Self righting is MUCH better now too. I'm thinking a a little taller stator and little less kv maybe the sweet spot to deal with heat better since I don't have a water cooling mount. Motor is the only thing that needs water cooling IMO, Esc is hardly warm. i will be tidying up the wires to lose some weight and clean up the inside.

    Proboat Jet Jam
    2212 4500kv upgrade
    9g digtal mg servo upgrade
    CC multirotor 35a esc upgrade
    Mike's subworks esc/tx adapter
    Dx5 rugged
    Sr215 rx
    Attached Files
  • Dr. Jet
    Fast Electric Addict!
    • Sep 2007
    • 1707

    #2
    I've had a lot of success with the little outrunners like you used in your JJ. I agree with you though, 4500rpm/V sounds a bit high for 3S, but I really don't know what kind of load the jet pump puts on the motor. If you are concerned about cooling, look specifically for a motor that has a cooling fan built into the can. It works surprisingly well, even in the cramped confined if a mini hull. Something like this may be the ticket: https://www.ebay.com/itm/Turborix-RC...wAAOSwxL1dVjnC This motor appears to have a bolt-on fan that attaches to the endbell.

    In my little 15" MHZ Shovelnose, I run a 3000rpm/V outrunner motor on 2S with a 29mm prop and I can easily blow it off the water if I'm going upwind in some chop. I run my minis mostly on 2S for a lot of reasons, but primarily because I'm cheap. Depending on the hull, I'll use props from 26mm through 32mm, although things heat up a bit more with the bigger props.

    When I was last at the pond, one of the guys showed up with a stock JJ. I wasn't that impressed, but it looked like it had potential with some upgrades like you have done.

    Keep us posted......


    UPDATE: I watched some YouTube videos of brushless JJs running. One common problem they seemed to have at this higher power level is cavitation in the impeller assembly. I would take an X-Acto knife or some needle files and remove any burrs or sharp edges in the inlet opening that would interrupt the laminar flow of water getting into the pump. You could even go so far as to make the "screen" bits of the hull into an airfoil (hydrofoil?) shape to reduce the turbulent flow going into to the impeller.

    Free speed!
    Last edited by Dr. Jet; 02-02-2020, 12:33 PM.
    A nation of sheep breeds a government of wolves

    Comment

    • FLMIBrewer
      Junior Member
      • Apr 2016
      • 16

      #3
      Originally posted by Dr. Jet
      I've had a lot of success with the little outrunners like you used in your JJ. I agree with you though, 4500rpm/V sounds a bit high for 3S, but I really don't know what kind of load the jet pump puts on the motor. If you are concerned about cooling, look specifically for a motor that has a cooling fan built into the can. It works surprisingly well, even in the cramped confined if a mini hull. Something like this may be the ticket: https://www.ebay.com/itm/Turborix-RC...wAAOSwxL1dVjnC This motor appears to have a bolt-on fan that attaches to the endbell.

      In my little 15" MHZ Shovelnose, I run a 3000rpm/V outrunner motor on 2S with a 29mm prop and I can easily blow it off the water if I'm going upwind in some chop. I run my minis mostly on 2S for a lot of reasons, but primarily because I'm cheap. Depending on the hull, I'll use props from 26mm through 32mm, although things heat up a bit more with the bigger props.

      When I was last at the pond, one of the guys showed up with a stock JJ. I wasn't that impressed, but it looked like it had potential with some upgrades like you have done.

      Keep us posted......
      I'm going to try 2s then, have not tried yet. Thanks for your advice.
      Attached Files
      Last edited by FLMIBrewer; 02-02-2020, 12:59 PM.

      Comment

      • FLMIBrewer
        Junior Member
        • Apr 2016
        • 16

        #4
        Is it possible and is there a correct way to install a fitting on the pump to help prime it faster and provide water cooling?

        Comment

        • Dr. Jet
          Fast Electric Addict!
          • Sep 2007
          • 1707

          #5
          Take a look at this video around 4:20. His approach was somewhat crude, but I'm sure there's a neater solution using the same concept.

          A nation of sheep breeds a government of wolves

          Comment

          • BeliaEllet
            Junior Member
            • Mar 2021
            • 1

            #6
            Hi....Had a snappy stock spat the lake (grieved, no video). Its stable and runs easily, yet somewhat delayed for my experience. Couldnt in any capacity make it flip to test oneself correcting highlight. Directing appeared to be somewhat less sharp than I might want, haven't tracked down a D/R to check whether there is seriously turning capacity with the servo.

            Likewise affirmed through Horizon that the ESC/rx isn't spektrum convention.

            pcb assembly in usa
            Last edited by BeliaEllet; 04-16-2021, 04:59 PM.

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