quick question about my setup

[kwiktsi]

This is about that 32" Delta Force copy that I bought off ebay. The motor is known to be too "hot" for that boat and a bit too small- BUT I have propped it down to a smaller prop and the boat will give me at least 7-8 minutes run time (probably more, but I never get a full run out of it ).

Now my problem- if I try to run it for the full charge without a break, after several minutes, it melts one of the motor wires off the ESC at the solder joint (same wire every time too..). If I bring it in and let it cool every 2-3 minutes, it is fine.

Sure, I'd say it is the motor drawing too many amps- BUT the motor is only rated at 50A max and the motor and battery temps stay in the 90's at the hottest indicating that it isn't pulling much amperage. Also, using the formula for approximate amp draw (Mah x.06/runtime) has me in the 40's for amp draw- which makes sense with my temps but should not be melting wires off like this.

Is it maybe just a crap ESC, or should I still look towards the motor? Is it possible something isn't setup right in the ESC programming causing it to get too hot? I'm waiting on the instructions from the seller on how to program it.

I'm tempted to try one of my hacker 70's in it, but I'm afraid to cook it if it is the motor causing the problems!!! Anyone know how good the ESC actually is that comes with it? How about maybe adding a cooling fan in front of the ESC to get air moving around it?

[ED66677]

did you get the one with 125A watercooled ESC and 2726KV motor?
what voltage did you ran it? 4S, 6S?
125A is not bad for sport/fun but 2726 KV is way too high!

[kwiktsi]

did you get the one with 125A watercooled ESC and 2726KV motor?
what voltage did you ran it? 4S, 6S?
125A is not bad for sport/fun but 2726 KV is way too high!

Yes, it is the 125A 2726kv combo. I know the KV is "too high", we've discussed it before :). My concern however is that running it on 3S with an X438 and getting the kind of run time I am getting out of it- I know there is no way in hell I am pulling 125A- especially since the "50A max" motor is still so cool- unless the cooling on the motor works that well???


Question- will there be that much of an amp difference between (assuming the same prop on either)- a 6XL on 3S (2779kvx11.1v=30,846 RPM's) or a 12XL on 6S (1390kvx22.2v=30,858rpm). I know they say to go with voltage and lower KV over less voltage and higher KV, but is there really that much of a difference? If I am going to get less run time with a lower KV motor and running 6S, yet get the same prop RPM and speed, what is the advantage? Especially since I am going from 10,800mah (3S2P) to 5400 (6S).

[ReddyWatts]

Reliabilty.

[kwiktsi]

Reliabilty.

So, are you saying that I'd actually be better off running 5400mah through 6S and a lower KV motor than I am running 10,800 mah through 3S and a higher KV motor? Would my run time be the same, better or worse making the change?

[ReddyWatts]

I think using a (HV) controller for higher voltage and less amps is the better setup for sport running.

FeCalc estimate.

6XL - 3s - 10800 mah, X440, 120 amps, 1200 watts, 26350 rpm, 110 max amps

12XL - 6s - 5040 mah, x440, 65 amps, 1350 watts, 27850 rpm, 55 max amps and 2.5 mph faster

They will have close to the same run time.

[kwiktsi]

I think using a higher voltage and less amps is the better setup for sport running.

FeCalc estimate.

6XL - 3s - 10800 mah, X440, 120 amps, 1200 watts, 26350 rpm, 110 max amps

12XL - 6s - 5040 mah, x440, 65 amps, 1350 watts, 27850 rpm, 55 max amps and 2.5 mph faster

They will have close to the same run time.

Wow, quite the difference in amp draw. So, even though I am splitting the MAH in half, I am also splitting the amp draw in half as well. Interesting. Plus, if this motor is underpowered for this hull (though the can is huge in diameter), then I can expect even better gains from a 12XL in both speed and amp draw. Thanks for the info! What did it estimate the top speed as?
Joe

[Raydee]

The problem with 6s is that most ESC's that claim to be able to run 6s will end up looking like Charcoal. I know it is possible and some guys have good luck doing it but its really a gamble. Will your ESC handle up to 6s?

[ReddyWatts]

It estimates 42.7 and 45.2 in a cat hull, but I do not rely on the speeds it calculates. Mainly look at the difference.

Use a LV 150 - 240 amp controller for the 3s - 6XL or it will be instant charcoal.

High amps are harder on your components than high voltage.

[kwiktsi]

The problem with 6s is that most ESC's that claim to be able to run 6s will end up looking like Charcoal. I know it is possible and some guys have good luck doing it but its really a gamble. Will your ESC handle up to 6s?

They claim it is 6S compatible... One way to find out :D. He's already refunded me some $$$ for the problems with the mis-matched setup, so if it can't handle it, it's no biggie and I'll just upgrade it. I was just trying to stay cheap with the setup and get it to work as it came out of the box.. Oh well.
Joe

[Steven Vaccaro]

Just remember that volts x amps = watts.
There are 2 ways to get to the same amount of watts. In my opinion High voltage is the way to go.

You will see many racers running 4s setups with high amp motors. The reason for this is they have a set voltage to adhere to. So the idea is to get as many watts they can safely run without burning something up. The only way to do that is the high amp motors.

[focused]

Hello ,

I`m new here and from the netherlands and have a MHZ Tsunami , simular to the delta force, i have a setup with 6s lipo Zippy 5000mah and a KB45xl8 with a grimracer metal 42x55 prop and a ETTI 125Amp esc. .
It reach speed up to 55 to almost 60 mpph (had a gps onboard) , so i also say yes to low revs en high voltages .

The esc gets warm , not hot, motor stays cold with full water jacket cooling .

About the hacker esc it can handle more amps then you think and will not burn that easily becouse it will shut down before it reach the critical temperature which i think the cheap china esc will not have or do .


Michiel.

[kwiktsi]

Just remember that volts x amps = watts.
There are 2 ways to get to the same amount of watts. In my opinion High voltage is the way to go.

You will see many racers running 4s setups with high amp motors. The reason for this is they have a set voltage to adhere to. So the idea is to get as many watts they can safely run without burning something up. The only way to do that is the high amp motors.

Thanks Steven, that makes sense. That why I was getting confused seeing all these people doing things on fewer cells. Did not consider that they are limited when racing.

I sent you a PM yesterday, I want to order a motor- do you have a number you can be reached at? I am torn between an 11,12 or 13XL. Thanks.
Joe

[kwiktsi]

Ordered a 12XL and cooling jacket. Payment was via paypal from sales at joepmbc dot com