Mg fire!!!

[hobie]

What? Now you've been running different motors? I give up. It's making my head spin.

No no, everything was stock.

Those are the things I want to try. Also just want to keep away from the low amp esc's that's all.

[Fluid]

This idea that an ESC has to get smoking hot before it blows is just flat wrong. If the ESC has been abused in the past - over-amped, hooked up with reverse polarity, run without being hooked up to the motor or with one phase not connected - it can blow at any time. Did both ESCs spark when you connected them to the packs? If not, it is no wonder they blew. Don't run an ESC that doesn't spark, you'll eventually be sorry. It doesn't matter what the amp rating is, without caps you'll lose the ESC. On, and a bad motor will kill an ESC quickly too.




* If the caps are still charged from being connected to the packs but not run, then they may not spark on the next connection.

.

[hobie]

Here's the pic of before, (doesn't look that bad) and an after shot once i cleaned it up a bit.
I'm going to try the Velineon system in it, start with a 7.4 volt battery, with a 440 to see what that does.
Will post my results.

[Fluid]

2S is not much power for that large 30" boat, you will not be happy with the speed. The amp draw will be high if you try to approach the speeds of the 4S boat, and the motor Kv is too high to go with 3S (if the ESC would handle it). Do yourself a favor and don't try to reinvent the wheel here. Use a proven 4S setup.


.

[hobie]

2S is not much power for that large 30" boat, you will not be happy with the speed. The amp draw will be high if you try to approach the speeds of the 4S boat, and the motor Kv is too high to go with 3S (if the ESC would handle it). Do yourself a favor and don't try to reinvent the wheel here. Use a proven 4S setup.


.

Ok, that does make sense a little. And yes, I'm new at this. (the whole reason for the post...) But.... Wouldn't it make no difference if you achive the same rpm with less voltage? How would 7.4 volts, or even 11.1 for that matter, draw less amperage than 14.8, or even 18.5?
This electronics crap is confusing. Isn't that what directly relates to speed?? RPM? the more rpm the faster you go?
I would like to know... If you can tell me, if I get (and I'm just throwing numbers out there) 30000 rpm from 6s and a 1500kv motor, or I use half the voltage, and twice the kv motor to achive the same thing. Wait.... Would that make it twice as hard for the 3s to get that rpm, or more draw, rather than a 6s.
Would that be the same as a big truck pulling a load up a hill, and then trying to the same with a small car??? Am I even close?? Lol!

[Darin Jordan]

Hobie,

Before you go burn up more equipment, start here and understand what you are doing:

http://www.sengpielaudio.com/calculator-ohm.htm

The formula you want to focus on is: P = V * I

Power = Voltage * Current

To achieve a certain amount of power, if you increase he Voltage, you decrease the current, and vice-versa.

So, when you drop the voltage to 2S, you double the current required to make the same amount of power.

You would be money ahead to put a proven system in there and stick with it until you are up to speed on RC Boating. The stock setup in this boat is capable of mid-40's and will do that for the entire safe discharge of the packs. In fact, I'm certain that, with a couple of tweaks, approaching 50 with the stock setup is possible in race trim (shorter runtimes, of course).

[hobie]

Thanks Darin! Great info. The electrical details so to speak is what I don't know much about. Been doing cars and planes for years, never burned anything. But I'm finding that water is a whole different ball game!
Ok, I will pull the Velineon system out. I will wait till customer service sends me a new one. I emailed them on sat saying the motor wouldn't work, they said they would send me a new one. But found out it wasn't, replied that it's the ESC, not the motor. Awaiting their email, but I'm sure they will send me a new one.

Again, thanks for all your help and info. I will try that offset rudder conversion to achieve my extra speed, not the voltage.

[Darin Jordan]

Again, thanks for all your help and info. I will try that offset rudder conversion to achieve my extra speed, not the voltage.

If you pay attention to what other guys are trying for props as well, you'll get yourself there.

One thing to keep in mind too... many car motors are only 2-pole or 4-pole setups... both of which can work in boats. However, they don't have as much raw torque as these 6-pole RTR motors, so you have to usually prop down to use them, and you can't swap them directly KV for KV...

Have fun!