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Old 01-11-2014, 04:50 AM   #1
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Default Lipo voltage, motor kv and gear ratios.

Hello, my doubt is if with 3S lipos (11.1V) i have to use a shorter ratio (large number) than with 2S lipos (7.4 v) with same number of kv but i suppose it also deppends on number of motor kv...


Example, for touring electric 7.4 and 4.5T motor, 8.5:1 ratio or more is usually recommended, but if I use a 4800 kv motor (dynamic 10 LRP) with 11.1V?

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Old 01-11-2014, 02:39 PM   #2
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You will want the ratio to go up. It is basically adding 1/2 as much voltage as you already had, which is quite significant.
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Old 01-11-2014, 05:05 PM   #3
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To go up ratio means shorter gearing?, you mean a final number ratio larger with 11.1 volts than 7.4?

But 4.5T is 7700 kv and 4 poles short course motor is 4800 kv..

7700x 7,4=56980

4800 x 11.1=53280

I lose some final rpm using 11.1V so i need to use little more taller gearing isnīt ?

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Old 01-11-2014, 05:20 PM   #4
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If rpm is that close i'd just start with the same gearing then go from there. check your temps and if its cool like less then 140F then maybe gear up a tooth or 2 on the pinion if you need more speed. if your speed is fine then leave it alone and enjoy a cool running motor. just dont go above 160-170F motor temp to be safe
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Old 01-11-2014, 05:30 PM   #5
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You have to remember that rpm isn't everything.

And...you are comparing two totally different motors, with different pole counts, and different ratings.

And where are you getting 4.5= 7700? It is different. For every motor.
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Old 01-11-2014, 05:32 PM   #6
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Try running the motor, temp often, and gear down or up as you see fit.
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Old 01-11-2014, 05:34 PM   #7
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Quote:
Originally Posted by ThePanda View Post
You will want the ratio to go up. It is basically adding 1/2 as much voltage as you already had, which is quite significant.
Here I thought you were talking about one single motor going from 2s to 3s. Not two separate motors, one on 2s, one on 3s.

Disregard what I said. In the quote unless you are only using one motor going from 2s to 3s
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Old 01-12-2014, 01:41 AM   #8
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Yes, I was talking about different kind of motors.

(Team Powers Plutonium 4.5T offers 7700 kv (rpm/volt), sensor at 0 position as is described at its manual guide.)


Thanks.
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