Twin Mean Machine Project Need some suggestions

[Jacked1]

I decided to build my first twin cat. The MM hull is on the way and I plan on 6s and going with two 200amp cheepo escs. I am going to use two of one of these two motors...
http://www.hobbyking.com/hobbyking/s..._Heli_(1100kv)
..or..
http://www.hobbyking.com/hobbyking/s...kv_(600_class)

Does anyone know if the typhoon will be able to pull about 90 amps without overheating? I have one but i don't have an eagle tree or amp meter to test it. I really wanna see what happens with the bigger ones because they are more power but they will be harder to install. I don't know if i will even be able to keep it in the water with that much power either.
There is a boat club kinda close to me that uses mostly gas and nitro so i want to scare them a little bit!
Thanks for any suggestions!!

[DISAR]

I 've seen a sprintcat with the turnigy 1100 kv
http://forums.offshoreelectrics.com/...ight=sprintcat

2 of these in a MM, 6s, 447 L&R should be OK

or I think these are better for more rpm

http://www.hobbyking.com/hobbyking/s...0_Heli_(1400kv)

[Jacked1]

Yea you have a good point, unless i went with 1100kv on 8s i would have to use some big props to get the prop speed up to where i want it and to push it like i want it i think i would need at least 70-75 mph prop speed at no load. I do have a couple 100amp hv controllers tho. I think the 1400kvs would do awesome! i think i will use those!

[DISAR]

Nice, 30,000 rpm is good and amp draw on 6s will not be high with the 447s but better to start with the 442s to check temps first.
My only concern is the motor mount which ones will you use? For escs the Turnigy 180 are super

[Jacked1]

That sounds like a plan! and thanks!

I am going super budget for this one so i am going to use 200amp cheep escs or the 120amp turnigys and make the mounts, I have access to a mill and sheer and i just bought a dremel and i have plenty of fiberglass and some aluminum solder to attach some cooling tubes for the mount. The hull is used and a bit of a fixer upper but will be good. I got it for 45 bucks shipped!

And the motors will fit nicely! There is plenty of room and I have a lot of cool ideas for this boat! I am very excited!

[Jacked1]

So my buget is so low i might just have to make this a single motor cat

[Jacked1]

I think i might just have to throw some more money at it! I love twins so i bet i will love a twin cat!

I have a turnigy 120amp laying around so i will get another one of those and go 2 of the 1400kv outrunners and some 4mm stingers just because the price and i wouldn't need too big of props at that rpm but i bet these motors could handle some big ones. I am pretty sure each motor can pull 110-120amps on 6s when i have it all together. 5300 watts (7.1hp) in a really light mean machine sounds good to me! But i don't care as long as it smokes the nitros!

And if all that power is too much and the hull breaks i have plans to start making my own fiberglass hulls next spring.

[Brushless55]

to me it sounds like you will need more kv
there is a guy on youtube who has a MM runing twin 8XL on 6s I think and getting 75mph

[Jacked1]

Yea i have seen that one! I am just going to use real big/high pitch props if i need to. I don't want to get too high in the rpms and if i need to i have a couple 100amp hv escs i can run the motors on 8s. I know there is a genesis on here somewhere that got 72mph on a couple of scorpion 1400kv on 7s with 80amp hv escs and X447s(i am pretty sure that is the prop but not 100%) and i know under load this motor will be able to turn the props better since it is just plain bigger and has a 30amp higher rating. And that setup is a 88mph prop speed!

I think with the 1400kv tunigys i will end up getting 120amps out of the motors and go with a x648 and have 92mph prop speed.

Now i need to decide on the tunigy 120amp or the himodle 200amp esc!

[Jacked1]

Going with the turnigy 120s! all the parts are on the way! (except props)

[LarrysDrifter]

Dont run the Himodel's.My buddy ran his boat for approx. 30 seconds and it died.

[FighterCat57]

Going with the turnigy 120s! all the parts are on the way! (except props)

The Aquastars?


Should be a fun setup!

[Jacked1]

The Aquastars?


Should be a fun setup!

Yupp!

I dunno what to do with props. I think it will be higher tourqe that a kb45 8xl and i have seen those with k48 props in a single motor on 6s so i think they can handle a k51 and stay under 120amps with the twin motors. But i am going to start with the k45s i think. I know mudl has 1400kv twin scorpions in his genesis with 80 amp hv turnigys with the x447 props. Man i wanna run these motors!! My big twin mono is almost ready for 6s and it will have two of the 880kvs of this motor.


And we just got the lathe working at my job today so i can start making most of my own hardware for practically nothing!

[Jacked1]

Dont run the Himodel's.My buddy ran his boat for approx. 30 seconds and it died.

Yea those things are really hit and miss. I have had good luck so far with the aquastars.

[FighterCat57]

I've had real good luck starting with ridiculously low prop sizes and working my way up. It's also a good way to ensure a successful maiden run and get the bugs worked out of the hull/hardware before adding speed into the equation. In some instances, I've actually lost speed going bigger on the prop. All theory and calculations go out the window when it comes to real world trial and error.

Those are high torque motors, K45's would probably be good start. I'm getting ready to do something similar and planning to start there on a smaller hull.