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  1. #1

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    Where Should My Center Of Gravity Be?

    I originally set my Revolt 30 up with a rather heavy Garmin GPS in front of the batteries so I could see which prop would give me the most mph. Now that Ihave chosen a prop which works quite well I took the Garmin out. Went to run the boat today and noticed a little problem. It runs smooth and true at half throttle but when running WOT the bow gets a little too light and the whole boat rocks violently from side to side. If I don't back off on the throttle it will get airborn. Before I adjust the plane tabs in the back I thought Iwould find out if my CG was even close to where it should be. On a 30" hull without the Garmin weighing the front down my CG was about 8" from the stern. I decided to shift the batteries forward in the tray and now the CG is 9 1/2" from the stern. I will test it out tomorrow but just wanted to ask if there was a general rule where the CG should be?

    Thanks in advance for your help,
    MadDog

  2. #2
    kilr95ss's Avatar
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    RE: Where Should My Center Of Gravity Be?

    A good rule of thumb is 28%-33%, 28 being 8.4" from transom, 33 being 9.9" from transom for a 30" hull.
    Charles Spradley
    When in doubt, GAS IT! This will either fix the problem or end the suspense.

  3. #3

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    RE: Where Should My Center Of Gravity Be?

    Thanks, that is what I needed to know. It looks like I was 27% but now set up better at 31.5%.

    MadDog

  4. #4

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    RE: Where Should My Center Of Gravity Be?

    also the prop can toss the hull around like your describing
    a prop with more lift will cause the boat to run loose
    first to own the Mini Slash!
    Amsoil Dealer.. 6XL Revo, Baja 5B, Losi8T, PS295, UL-1, AQ MC, OM29, DF33

  5. #5

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    RE: Where Should My Center Of Gravity Be?

    srt10:

    I thought about the prop but the boat was very stable with the weight of the Garmin in front of the Lipos. The problem started when Iremoved the Garmin. I have shifted the Lipos forward changing the CG and will test it out tomorrow. Iwill report back after tomorrows run.

    MadDog

  6. #6

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    RE: Where Should My Center Of Gravity Be?

    keep us posted bro
    first to own the Mini Slash!
    Amsoil Dealer.. 6XL Revo, Baja 5B, Losi8T, PS295, UL-1, AQ MC, OM29, DF33

  7. #7

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    RE: Where Should My Center Of Gravity Be?

    Well, it looks like I got the CG correct. Runs like a dream WOT. Very stable and fast, nose comes up so the last 1/3 of the boat is in the water but will not get airbornand will turn on a dime on command. My only goof up today was that I ran it WOT until the batteries were depleted which caused the batt / ESCwires to get so hot they melted some of the floatation noodles I had stuffed down the sides. Next time if I run WOT it will be for 6 minutes max.

    MadDog

  8. #8

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    RE: Where Should My Center Of Gravity Be?

    Awesome news!!
    What prop did you go with Dan?
    first to own the Mini Slash!
    Amsoil Dealer.. 6XL Revo, Baja 5B, Losi8T, PS295, UL-1, AQ MC, OM29, DF33

  9. #9

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    RE: Where Should My Center Of Gravity Be?

    I got a prop from Chris that he sharpened and balanced for his Revolt 30. It isa 47x50 and Ibelieve the stock prop is a 42x55. Not positive about those sizes but my GPS shows a definite increase in speed.

    Dan


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