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Thread: Good CG range

  1. #1
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    Default Good CG range

    So I've about got the boat together and started with a bare hull. What is the best CG on these? First Hydro coming from mono. I know that 2/3ds toward the rear is good for monos but thinking Hydros want more in the center if not forward a hair for good sponsoon tracking. :). Also I would like to see weights of these and asking anyone with heavily modded boats what your wet weight is. (fully loaded with batteries.)

    I'm sitting at 5 Ibs. 3oz. right now. but need to finish some coolant line and S+B the prop
    Kyosho K.I.T.T.

  2. #2
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    Hi.
    Have any pictures of your boat and setup inside of the hull ?
    How big is the boat and on what cells will you be running ?

  3. #3
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    Quote Originally Posted by lenny View Post
    Hi.
    Have any pictures of your boat and setup inside of the hull ?
    How big is the boat and on what cells will you be running ?

    lol well It's a normal RTR UL-1 Dont really know if there is much of a variation size wise from revisions. I'll be running 4s. As soon as I get the cooling tubing done Ill post some pics.
    Kyosho K.I.T.T.

  4. #4
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    Here's some pics...

    2012-09-29_16-18-04_104.jpg
    2012-09-29_16-09-22_557.jpg

    I also had to repair the left sponsoon and it was cracked in a few spots so i just sanded things down and epoxied some carbon on it.

    2012-09-29_16-18-30_794.jpg


    Same with the Transom.

    2012-09-29_16-09-13_766.jpg
    2012-09-29_16-08-50_81.jpg

    I am running two pickups as the tiny rudder one doesn't sit well with my motor size.

    ...and i know I am running too small of battery connections but I had a ton left over from the cars and when I am a little more better with finances I will upgrade to 5.5's, kinda why I screwed up the soldering job on the Y harness :)
    Last edited by MR2NR; 09-29-2012 at 07:20 PM.
    Kyosho K.I.T.T.

  5. #5
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    COG on this hull should be an inch and a half to three inches behind the sponsons Matt.

  6. #6
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    Run the batteries as far forward as possible. What motor is in there?

  7. #7
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    I think it is a 3674 2200kv.
    But not sure on that.
    He said it was stock setup.

  8. #8
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    Stock Hull but all the internals is aftermarket except the servo. Leopard 3674 2200K is correct. Using Gens Ace 2200 60c Batts 4S. They are in the pic :) Shoved as far forward and outboard as I have seen :). But ya run time will be around 15 min I'm guessing.
    Kyosho K.I.T.T.

  9. #9
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    Just budding in here, I have the same set up with that motor running 4s 5000mah 40c-50c burst
    with a m445 s&b, running in the 50 range but I don't belive you will get 15 min run time out of it, more like 4-5 min, but anyway run it for a few laps and check temps.
    jmo, have fun.

  10. #10
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    How much time are yours getting? If things are that bad Ill just run 2s for fun and 4s to race. :) I also have some hardcase 40'c but cant get them in the hole :).
    Kyosho K.I.T.T.

  11. #11
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    Like I said I'm getting about 4-5 min on 4s thats 2x2s to make 4s, I not sure but that motor won't perform on a single 2s.
    I could be wrong, just never ran it or tryed it on 2s and only 7.4 volts it will be slow.
    Everything I read in this site says most all fe boats run between 4-6 min.
    if your getting 15 min run time thats great, but hard to believe on 2200 mah batterys.

  12. #12
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    Well on my mono I can get 30 min with 5000mahs so I was just halving it :). Ill bet you are right though with a hydro and bigger prop. I really like how these batts. fit though. I was thinking I could just by another pair and put them in parallel and double the Mah but I hate the way you have to splice solder. Would be cool if they made a 5.5 Y or T bullet or is there a better way ? Maybe stick a 5.5 in a 8 solder hole.
    Kyosho K.I.T.T.

  13. #13
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    Are you running in series or paralelle ? spelling, you know what I mean.
    Even on my impulse, still only getting around 4-5 min on 5000mah and when recharging them i'm putting 3800-4000mah back in.
    you should leave about 20% of charge in the batterys.

  14. #14
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    Quote Originally Posted by MR2NR View Post
    Well on my mono I can get 30 min with 5000mahs so I was just halving it :). Ill bet you are right though with a hydro and bigger prop. I really like how these batts. fit though. I was thinking I could just by another pair and put them in parallel and double the Mah but I hate the way you have to splice solder. Would be cool if they made a 5.5 Y or T bullet or is there a better way ? Maybe stick a 5.5 in a 8 solder hole.
    What kind of mono?

  15. #15
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    Quote Originally Posted by G-UNIT View Post
    Are you running in series or paralelle ? spelling, you know what I mean.
    Even on my impulse, still only getting around 4-5 min on 5000mah and when recharging them i'm putting 3800-4000mah back in.
    you should leave about 20% of charge in the batterys.
    Both if I get two more packs. Parallel batts. Series to the ESC. so I would be at 4400mah with four 2200mah batts. I have 2 on board voltage meters on each batt. so I know where Ill be I heard that the ESC Im using isn't very reliable with voltage cutoffs so I am not relying on it :).

    I mainly did this because i wanted the batts. to be as far outboard as possible and the hull came with a huge hole in the front so why cut it up any more :).

    Dana I am referring to the Jet Stream in my avatar. It wasn't very fast though so Im taking that into account that as well.

    I'm thinking now I will need the extra batts but of course I bought the last two HP had lol. I prob have the lightest UL-1 though right now lol. Might run it one or two passes and see where I'm at.
    Last edited by MR2NR; 10-04-2012 at 03:16 PM.
    Kyosho K.I.T.T.

  16. #16
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    Well after about a year I finally got the S+B prop back as I was lazy and really hadnt had much time lately to go get it. But the boat really didnt want to go like it should. I could get it to plane but barely as I'd say it's prob running 15-20 MPH. I'm afraid my prop is not thin enough. Does OSE sell a thin enough 40 57 prop for the UL-1 S+B'd from them?
    Kyosho K.I.T.T.

  17. #17
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    Just went out again and stuck the strut down and got her to pop out super easy and she did the basic 25-30mph ya! Now I need to up the battery's.
    Kyosho K.I.T.T.

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