29.5" mean machine Cat

[skiaddict00]

i just purchased the 29.5" mean machine cat hull, the hydra 240, and i have two castle creations mamba max 5700kv motors. i was wondering the best way to determine prop size and where to start so i dont have to spend Much more money on my boat. my bank account already hates me. also should i run the motors opposite directions with opposite props so it will handle better. this is my first serious boat assembly... i've done a cheap kit that doesn't even move. any suggestions are welcome....

thanks
James

[skiaddict00]

and also what kind of shaft should i run?

[SJFE]

We need a little more info to help ya out. Is the hull equiped with hardware? If you have 2 motors you will need another matching esc...that will cost you. My suggestion would be to sell those motors as they are to small. Take the money and buy a Feigao 10XL or KB45 8-T motor. They are better suited for that hull.

[SJFE]

Here is a excellent example of how to set up your hull

MM Sport Setup By ReddyWatts

[NorthernBoater]

What kind of batteries do you plan on running?

[Fluid]

You will need a miniumum of 12 cells/4S to make that hull perform well. The motors you have are totally unsuitable for that hull, the suggestion of a 10XL motor is a good one. That is a great hull but it is heavy and needs some real marine power, not toy car power.


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[skiaddict00]

i purchased the hydra 240 speed control, which appears to have two battery inputs and two motor outputs. i purchased the hardware that i need... or at least what i think i need. i ordered two Ib4200 7 Cell Hump Packs, 2 OSE DR Motor Mounts, and the Speedmaster 21 Rudder 5.25" Long. if these discriptions seem retarded it's because i took them from my order. i don't think it's shipped yet so i should be able to call tomorrow and return part of it before it ships out. i am not sure what other hardware i need and i don't know what shaft type or size i should run. as far as lithium batteries would it be better to cancel the batteries i ordered and purchase some lipos? if so which battery would work best?

[Mich. Maniac]

are you still gonna run those motors? or are you gonnna go with a 10xl? If you wanna get that motor I would tell Steve you wanna change it. you need the right motor in there and get it aligned before you need batterys.

[Mich. Maniac]

also if you went with the 10xl you could just run a 120 hydra instead of 240. just trying to save ya some money and headache

[skiaddict00]

i'll probably go with the suggested motors.

[FE_Chris]

These dudes know what they are talking about, tru$t me I know

Sounds like a nice build, make sure to take some pics and a video for us.

i'll probably go with the suggested motors.

[skiaddict00]

can you run both motors on one 120? can you run both on one 240?

[ReddyWatts]

The short answer is "no" for brushless motors.

[FE_Chris]

I'm no expert, but I do a lot of reading. From what I understand it is not feasible to try and run 2 brushless motors from one ESC, like you could do with 2 brushed motors and one heavy duty brushed ESC.

Something to do with the rotor position of and 2 motors being different and the ESC needing to know what position they are in, I guess it cannot work with 2 motors. Something will fry I am sure.

Speaking of 2 motors, I also read that you do not really want 2 motors. It looks cool, but people max that hulls speed out with one motor no problem. (around 40stable and 50 on smooth water, again from what I read)

I know someone said it, sell the MM motors and get a 10-11XL motor and be done with it. I know the mamba max motors are worth more together, even used than one new feiago. That hydra 240 is supposed to be heavy duty! you should be able to get stuck in the weeds all day long and that ESC should hold it's own!

Good luck. Keep is informed.

Also, that post that link's to ready watts post is a good one. He has lots of recommendations that seem to work well for people.

can you run both motors on one 120? can you run both on one 240?

[Fluid]

can you run both motors on one 120? can you run both on one 240?

As stated above, it is best not to do so. The reason the Hydra240 has dual wires is to handle more current - instead of using wire that is too thick to end, Castle chose to use two smaller wires - a common practice with high power ESCs.

You can run 14 cells with the 10XL, although it may be better to get an 11XL. Either will work fine, the latter will give a bit more run time. LiPo cells are "better" in that good ones give up more power and you can get cells with higher capacity for more run time, but they have a high front-end cost. You need to buy the cells and a LiPo charger. If you are on a budget then I'd suggest staying with NiMH cells if that is what you are familiar with. You can always sell the NiMH packs and get LiPos later when your budget allows.


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