basics of FE motor / ESC / prop planning

[anthony_marquart]

So I'm thinking some day maybe a FE boat,. I'm the only guy running nitro around here.

I understand nitro engine / pipe / prop,.. torque / RPM

FE totally do not understand.

For FE,..

Is there a power / RPM curve with electric? like a peak power point at a certain RPM?

can you plan,, say "this motor" has peak power at "???" RPM, I expect this boat to "???" MPH, so I need "??" prop,...

Does RPM go up from say 4S to 6S or is it just power output? like use same diameter prop but more pitch?

I don't know if these are even the right questions,.. just trying to understand.

I know with nitro,.. falling off in turns is too lean or too much prop,.. (probably) shorter pipe = more RPM and less torque,.. etc.. but I would like to understand how this applies to FE,.

Thanks

 

[lohring]

Start with Electric Power Basics.

Lohring Miller

 

[Curtis Beaumont]

So the basics with Electric:

Voltage is proportional to motor speed. You roughly get the same amount of torque out of a motor as you would at nearly the top speed (there is some drop off, but it is nearly the same). Since power is torque muliplied by speed, then The higher the speed, the more power it will produce. The higher the voltage, the more power. The problem is when you increase the speed of a boat, the drag increases too. When you increase the speed of the boat and the drag increases, the power consumption increases with that, and if you were able to keep the voltage constant, the power consumption comes out in the form of current (Amps). If you want to get into electrics, start with a good data logger (I would use an Eagle-Tree DL). This will give you the ability to hook up at a minimum, the Battery pack which will tell you the current consumption (this will tell you if you are hurting the motor, ESC, battery) as well as what the voltage is doing when you are pulling a certain current. You can also connect a GPS module to see if the power draw is translating into speed or not.

There's a lot of information out there. Feel free to send me a note if you want any direction.

Regards,

Curtis