Set-Up Choices 32" CAT

[OttoSea]

I've become the owner of a 32" FG Cat and hardware.

Limited to to 2SP battery set-up by configuration.

Not looking for max speed, but would like to have some fun.

Have a Swordfish 120 ESC.

Looking for motor and prop suggestions.

Any guidance appreciated.

John

[keithbradley]

What do you mean by 2SP?

[OttoSea]

2s LiPo batteries in parrell

[keithbradley]

Oh, ok. That would be 2s2p.
2s is pretty low voltage for a 32" cat. Is there any reason you wouldnt run 4s?

Also, what are you looking for as far as quality/price? Fightercatracing sells some outrunner motors that are fairly inexpensive and would work well. Their 3730 / 1580kv outrunner on 4s would be very similar in performance/speed to a lot of out of the box brushless boats. If you were to run that motor with an x445 octura prop or 45mm carbon prop you would get decent speed but not something you are going to be constantly flippin gand crashing. You would also get pretty decent runtime with that setup.

Thats a start...depending what your goals are...

[DyrtyByrd]

is it a single drive setup? if so you could go with any of these and be ok
1 leopard 4074 1774kv
2 your 120 esc
3 442 or 445 prop
4 4s2p( 2x 2s lipos in paralell)
you would be turning 26255 unloaded rpms decent fun setup not too fast

or

1 leopard 4074 2000kv
2 your 120 esc
3 4s2p
4 442 or 445
29600 unloaded rpms decent mid performance setup fun but still have some speed

or

1 leopard 4074 2200kv
2 your esc
3 4s2p
4 442 445
32560 unloaded rpms decent fast setup maybe mid 50s with 442? maybe low 60s with 445?
only thing is im not sure about running this setup with the 120 amp esc maybe need a t180 or sworfish 200 amp

[DV8ion]

What would a 8xl on 4s with a X642 prop run ? amps, speed?

[Fluid]

The OP has yet to confirm if he is running 2S or 4S. Until then we can't help him much.

2S means two LiPo cells connected in series = 7.4 volts
4S means four LiPo cells connected in series = 14.8 volts

2P means two packs connected in parallel = twice the mAh
2S2P means four cells total giving 7.4 volts with twice the cell capacity
4S2P means eight cells total giving 14.8 volts with twice the cell capacity




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[D&D]

I'm never going to get this "electric stuff" right! I thought 4S2P was 29.6V, so what is 4S2S? Anybody know a good book to read on this subject??

[OttoSea]

I also need to learn more about the electrical side.

I'm running 2S2P, four cells total giving 7.4 volts with twice the cell capacity. The packs are 5,000 MAH. I'd prefer larger packs, but this boat has a height restriction. I could run the 2 packs in series for 14.8 volts, but was trying to trade voltage for longer run time, since speed wasn't the primary objective.

My initial thought was to run a higher KV motor at the lower voltage.

This is were I'm at.

[siberianhusky]

each cell is 3.7 volts, cells in series you add the voltages together, so a 4s pack is 4 cells each having 3.7 volts. so 4 x 3.7v
When you paralell the packs you add the capacity together.
Take 2 5000mah 4s packs. This would be 4s2p
4s would make 14.8 volts because its 4 cells in series, 4 x 3.7.
The 2p takes the two 4s 5000mah packs and adds the capacities together for 10000mah @ 14.8v.
Series you add the voltages together
Paralell you add the capacities (MAH) together.
MAH is milli-amp hours, a 5000mah pack will deliver 5000mA for 1 hour, or 5 amps for 1 hour. (In theory, you can't discharge a lipo to 0, kills the battery!)
A 20c 5000mah pack can safely supply a max of 100amps, take the C rating and multiply by the capacity.
So if your set up draws more than 100 amps this battery would fail pretty quickly.
Hope this explains it a bit!

[Alexgar]

a higher kv motor on less voltage equals more amps i think i would go low kv higher voltage and will be far more reiliable

[Alexgar]

a 9xl or a 10xl on 4s would be great maybe eve go 11-12 if you wanted less speed and loger run time but by halfing the voltage the amps double then you have to worry about your esc and 120 in pushing it in a fg 32" boat

[DV8ion]

a 9xl or a 10xl on 4s would be great maybe eve go 11-12 if you wanted less speed and loger run time but by halfing the voltage the amps double then you have to worry about your esc and 120 in pushing it in a fg 32" boat

Running the 9XL on 4s in this boat would give you about how much speed?

[keithbradley]

I also need to learn more about the electrical side.

I'm running 2S2P, four cells total giving 7.4 volts with twice the cell capacity. The packs are 5,000 MAH. I'd prefer larger packs, but this boat has a height restriction. I could run the 2 packs in series for 14.8 volts, but was trying to trade voltage for longer run time, since speed wasn't the primary objective.

My initial thought was to run a higher KV motor at the lower voltage.

This is were I'm at.

Use high C rated packs (30-45C) and you can get away with running 1p.

The pack configurations are quite simple really, it doesnt require much learning. "s" stands for series, and "p" stands for parallel. From that you can figure out what you have. The number in front of the s will dictate voltage, while the number in front of the p will suggest what your total capacity is. From there you can figure out how you want to accomplish your configuration.

You will get a million suggestions on what to run, especially wihtout specific goals. If you come up with an amount you want to spend, a speed you would like to attain, and a runtime goal, you will narrow things down a bit.
FYI- There are a couple combos listed here that I personally wouldn't reccomend running on a 120A esc. Just my opinion, but pushing the current limits of your esc is only going to shorten your runtime anyway. Let us know some more specific goals and we can send you in the right direction.

Also, More mah doesnt always mean more runtime, especially at the expense of voltage. My 32" cat is running 5000mah and getting more runtime than any other cat I know of at the speed I am getting.

[ray schrauwen]

Toss a UL-1 motor in there and run it on 4S1P 14.8V total with a 45mm prop and you will have lots of fun close to 40mph.