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Brushless Motor KV

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Old 09-13-2017, 05:33 AM
  #1
EField18
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Default Brushless Motor KV

Hello,

I have a 4700KV motor, which turns out is too much for a slash 4x4 and the motor over heats. The guy at the hobby store told me that a 3800KV is the max I should use so my question is can I limit the KV of my current motor with the ESC or via the settings on my controller to limit it to 3800 or do I just need an new motor? or is there another setting or configuration that I can use to keep it from overheating? I'm also using 4S batteries.

Thanks in advance.
Eric
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Old 09-13-2017, 04:15 PM
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RustyUs
 
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Welcome to RCU.

4S LiPo packs? Holy cow! Why? Sorry. I have to ask as I'm trying to understand your situation better, and what the need for 4S is. I'd would probably look at a maximum of around 2650Kv . Motors come in different lengths. The longer the can, the more torque, and better gearing options to remedy heat issues. What 3800Kv motor were you looking at? Check the specs before you throw that much juice at something. Higher voltage, and lower Kv equals more efficient power plant.
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Old 09-13-2017, 08:19 PM
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bill_delong
 
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Yes, the guy at the hobby store is correct, the highest kV I've ever seen for a motor that supports 4S has been 4400kV but even that's a stretch and will limit what gearing you can run, more info here, use the chart linked below to cross reference the 4400kV to handle up to 18V where a fully charged 4S pack = 16.8V:
Tenshock 4 Pole SC401V2 Motor

You can also limit the amount of current drawn by reducing the EPA (End Point Adjustment) on the throttle for the Tx (transmitter), this will effectively reduce the average voltage so you can continue using your 4700kV motor on 4S, simply use a temp gun to check what you need to adjust the EPA with the following recommended max limits:

Battery < 120F
ESC < 140F
Motor < 160F

Here is the temp gun that I like to use:
https://www.harborfreight.com/non-co...ter-93983.html


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Old Yesterday, 10:33 AM
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SlashMaxx4x4
 
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I run a CC MMX 2200kv and love it on 4S, and its absolutely insane on 6S.

Runs cooler than a cucumber, even in 90 degree weather.

I highly recommend it.
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