Thrust vs Drag prop switch

Discussion in 'Construction' started by donanton, Nov 15, 2007.

  1. donanton

    donanton Member

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    Aug 31, 2007
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    I am looking at building a Maryland class battleship. It has 4 props, but only 1 rudder.

    Does anyone know how to make it so when the ship is going straight, all 4 props are pushing. BUT when the ship is turning 100% of the way, 2 of the props stop pushing and act as drag props to assist in turning while the other 2 still pushing.

    Could that be accomplished by having terminals that when touching, give power to the motors that are connected to the temporary drag/drive props not touch when turning all the way, henceforth not deliver power to the motors, when the ship turns?

    Or am I just overcomplicating this and should just use the standard setup for drag/ drive props?

    Although slowing down on a turn might give you a little longer with your stern guns on target.

    Thanks,
    Anthony
     
  2. JustinScott

    JustinScott Well-Known Member

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    Oct 20, 2006
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    2,211
    Location:
    Dallas
    Yes, there is a mixer available from a british company Astec.

    Visit this site

    The mixer takes throttle and left/right rudder and mixes it into 2 additional channels to run the left and right motors.


    Problems with this:

    1.) You have to buy 2 motors and 2 ESCs. & install all that into your boat... There was hardly enough in my NJ when I played around with this concept last year. ESBG has a Tirpitz that has this installed and active.

    2.) I know know of no ruleset that will allow such a set up. Check with your local club and realize you might not be able to go to NATS.. unless its disabled.
     
  3. Mark

    Mark Active Member

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    Swansea, MA
    that mixer is made by graupner, and you can but them though Hobby Lobby, I just got their new catalog in a couple of days ago and saw it in there.
     
  4. JasonC

    JasonC Active Member

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    Jan 13, 2007
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    is there a reason y ur running all 4 props? cause if not then only run the inner 2 so the u have all the speed there and the means max wash running over the rudder. also 4 props mean 4 mortors and more battey drain
     
  5. Buddy

    Buddy Active Member

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    Newark Ohio
    HI guys well first off what speed are you trying to obtain? If you are going for fast or small gun you only get about 26 sec in 100 feet. In which case you are over thinking the whole thing. You are adding more things that can go wrong at the worst possiable moment.You will burn up more battery power by running 4 motors then you will by useing only 2. You can easily use gear drive to over come the slowing down in hard turns thus keeping your speed up.I suggest useing the stock 550s and gearing that down to 3 to 1 ratio and it should push her along real close, you can then use a electronic speed control to dial in your speed.
    Buddy
     
  6. djranier

    djranier Well-Known Member

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    This Motor controller will do everything that you are trying to do.

    Visit this site

    Has built in mixing, just Y the rudder servo, and hook up the jumper. I use the 10 amp version, and my ship will actually sit still, and just rotate in circles, but I cannot use that function, since the MWC does not allow it. :-((
     
  7. donanton

    donanton Member

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    Aug 31, 2007
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    Ok. I was very much overthinking it. I'll use the usual 2 drive and 2 drag prop design.