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Old Jul 27, 2014, 01:38 AM
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You build a Genesis twin, what is your setup ?

Hi,

You made a Genesis with a twin setup? What is your setup?
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Old Jul 27, 2014, 07:43 AM
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Hi, I am in the middle of building one and are about to finish. Here's the setup I am using:

2x Leo 3674 2200 kv
2x Seaking 120A
2x 4s1p 5000 mah
40er Prop

Once I have completed and did some test runs I am going to post some more info here!
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Old Jul 28, 2014, 09:13 AM
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Quote:
Originally Posted by derdirk View Post
Hi, I am in the middle of building one and are about to finish. Here's the setup I am using:

2x Leo 3674 2200 kv
2x Seaking 120A
2x 4s1p 5000 mah
40er Prop

Once I have completed and did some test runs I am going to post some more info here!
helo,

this will work, but 3660 or 3665 are enough and 2x4s1p are really heavy, il would be better to have 2x4s1p 4000 65c, and 2 x 3660 /2450.
best would be 2x 3660 3Y or 3.5Y, 2x3s1p 5000 65c.
this setup is for 100 + km/h
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Old Jul 28, 2014, 10:45 AM
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Do you think the 4S I will be using are too heavy for that? They are 520g each.

The 3S are around 450g depending on the brand..

I might try it with 3S and 4S and see how it goes.
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Old Jul 29, 2014, 05:03 AM
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It is a combination, 3674 are for 150Km/h or more, this is extra weight if you plan to go at less than 90 Km/h, the same for batteries, same brand, same 'C", it is 140grs per cell.
You will carry 500grs extra weight in total , this will increase the drag and amperage.

to give you an idea, a single 350 grs motor pushes the Genesis above 100 Km/h. two motors will only help to reduce the slippage and get a better stability, but weight will increase. It is a good thinking to put less than 300 grs motors.
These motors: are good for 6s twin:: http://hobbyking.com/hobbyking/store..._Inrunner.html or Sk3 1600 kv for more speed:less weight.
Be carefull with the size of the Lipo, the floats are not so wide. Do not use less than 40Cbatteries.
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Old Jul 29, 2014, 06:56 AM
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Thanks a lot for the advice - maybe I should try smaller motors first before putting the big ones inside.

Besides, I was planning to put the batteries in the middle and not in the floats.

What would you suggest in general, regardless the motors? Is it better to have the batteries in the floats or in the middle?
I have seen different set ups in the internet but couldn't find suggestions of which is actually better.
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Old Jul 30, 2014, 02:51 AM
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Joined Apr 2010
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I also would not use a seaking 120A ESC with the 3674 Leopard. For this motor i would use a Seaking T180 ESC.

Always put the batterys in the floats. This will improve (i.e. lower) the center of gravity and increase the inertia along the longitudinal-axis.
Both things are good for increased stability.

A twin motor solution is technical challenging and the sound of the boat ist great. But a single motor set-up is much easier and also works perfect.

Roland
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Old Jul 30, 2014, 08:00 AM
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Thanks a lot for your feedback.

I am actually running the 3674 2200kv motor and T 120A ESC on another boat without any problems - also on 4S.

Do you think for the Genesis I would burn the ESC? Based on motor specs it should be fine.
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Old Jul 30, 2014, 10:19 AM
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derdirk
In short you haven't burnt up the T-120 because you haven't tried to run a prop that draws more than 120 amps, simple as that.
It is the prop that determines the load, no idea why people think the motor has anything to do with amp draw.

That hull can easily handle the 4s 5000mah packs. In fact if you plan on pushing things you do not want less than 5000mah per motor unless you like very short runs at 120 amps draw you are using 2 amp hours of your batteries potential 5 amp hours every minute.
Race boats of similar size running open 4s class run 8000-10 000mah capacity for about 4 minutes or less of actual racing.

Just ignore all of this except for the 40c battery part.

"It is a combination, 3674 are for 150Km/h or more, this is extra weight if you plan to go at less than 90 Km/h, the same for batteries, same brand, same 'C", it is 140grs per cell.
You will carry 500grs extra weight in total , this will increase the drag and amperage.

to give you an idea, a single 350 grs motor pushes the Genesis above 100 Km/h. two motors will only help to reduce the slippage and get a better stability, but weight will increase. It is a good thinking to put less than 300 grs motors.
These motors: are good for 6s twin:: http://hobbyking.com/hobbyking/store..._Inrunner.html or Sk3 1600 kv for more speed:less weight.
Be carefull with the size of the Lipo, the floats are not so wide. Do not use less than 40Cbatteries. "
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Old Jul 30, 2014, 10:30 AM
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@Sibe

Good to know, thanks!

Well, I am not into racing and my aim is not to create the fastest Genesis or to reach 150km/h - it is my hobby, simple as that, and I prefer race boats over scale boats.

My Monos reach all around 80+ km/h which is fast - I think

The idea of the Genesis was to get better stability with the twin motor set up, plus I prefer the look of a twin vs single.
Anyhow, I don't aim to push the boat to hard or to reach top speeds of 150+ km/h.

I am happy if I can get around 100 km/h and at the same time enjoy the run with decent run times.

I am thankful for all your advise and suggestions!

What would be an ideal set up in my case?
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Old Jul 30, 2014, 11:36 AM
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hello,

ignore what Sibe says, you are not building a race boat for 4 minutes to run. on a Oval A twin catamaran on 6s 5000 40-65c will do 100km/h with a 6-8 minutes run time.
The suggested motors are good, the 120 A controllers, and 6S also 5000.

I have 3 cats, and I know what I talk of.
My HPR 115 has two 3660motors 850KV , 12s 5000mAh 20C, 2 x 80A Hv controllers, X442 props. Total weight is 4.8 kgs, speed 120 km/h, runtime : 8-10 minutes
You can follow any advice, but the genesis is not a race boat, it is "designd" for long straights, and "low" speed cornering..

good luck!

Vincent
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Old Jul 30, 2014, 11:38 AM
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Quote:
Originally Posted by Sibe View Post
derdirk
In short you haven't burnt up the T-120 because you haven't tried to run a prop that draws more than 120 amps, simple as that.
It is the prop that determines the load, no idea why people think the motor has anything to do with amp draw.
Physically absolutely right.

Most people use bigger motors with much larger or too large props because they think the motor is capable of that, ignoring the massive increasing amps. And then that will happen what you predicted.

I like to design my systems on the safe side and have a little bit reserve.

Roland
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Old Yesterday, 04:02 AM
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Joined May 2012
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Derdirk just do a youtube search for a genesis twin cat you will see plenty of video proof brushman has no clue what he is talking about, just finished watching a video of on running a pair of 4082 motors with a pair of 6s 5000mah packs, a lot more weight than you are looking at running and you can see how well the boat runs.
Plenty of people post the specs of their builds with the videos, also join up at Offshore Electrics forum, that is the place for info from real top level racers. They will set you straight, believe there are a few current genesis threads running now about this boat. Along with 100's of older threads.
There is a lot of disinformation flying through this thread and I don't want to see you steered in a wrong direction on you build from bad advise.
Your original specs were for a good solid setup although I personally would run a t-180 esc for more headroom. Probably will NOT get you to 150kph though, lots of people want to hit 100 mph but very few actually do with any reliability or repeatability, it's kind of the holy grail of the speed guys to crack 100. It is more about boat setup and experience than power.
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Old Yesterday, 04:19 AM
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Joined Oct 2007
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just funny, Sige! Of course you can put what you want in a hull if it is still floating, it is not a good criteria...If you want to learn, just buit a genesis my way, and buiilt another one your way, you will be surprised...
Ok Sige, I prefer light setup and High voltage. Which motor and controller would you use for a 10kg mono boat running at 70 Km/h with 12S 16Ah batteries?
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Old Yesterday, 10:45 AM
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Thanks again everyone - I think I will try the motor & ESC I have chosen for now and might upgrade to 180A later to be on the safe side.
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