Lower Motor Temperatures!!

WIZARDRC

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Hello everyone, I have a Granite BLX 3s and have been running it hard since I made the purchase. Unfortunately for the past 2 weeks we've had an oppressive amount of humidity and heat in New York City which has lead to extremely high motor temperatures. Before anyone asks, I do have a motor fan and even this struggles to dissipate the heat. I think I've found a solution that aids motor temps; according to my readings and conditions by approximately 20-25 degrees Fahrenheit.

Step 1:
Definitely have a motor fan to begin with.
Step 2:
Purchase thermal compound designed for computer processors. (I am using Arctic Mx-4 from Amazon)
Step 3:
Remove motor heat-sink and apply a generous amount to wherever the heat-sink comes in contact with the motor. Make sure to spread this out with your finger or Q-Tip.
Step 4:
Reapply the heat-sink and wipe off any excess that may have oozed out. I recommend a paper towel with alcohol since the thermal compound can be quite sticky.

I know some of you may be thinking doesn't this stuff attract dirt? You're certainly right in thinking that, but if you wipe a lot of the extra off, dirt struggles to penetrate the area between heat-sink and motor. Also for those of you who may be wondering my conditions are as follows so your mileage may vary... ~95 degree Fahrenheit heat, ~75-85% humidity, hard bashing on grass, gravel, loose dirt, and a skate park, stock 3s electronics (esc/motor)

I've been using this for about a week now, and I'm hoping this helps anyone with overheating issues. Just make sure you already have a fan installed to properly take advantage of the thermal compound heat conductivity!
 

WIZARDRC

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What were there before and after temps though ?
I reached a peak motor temperature about 2 days ago of 170-180 Fahrenheit at 1pm. After applying the thermal compound I had laying around I charged batteries and went back out around 4pm. Temperatures after a battery long bash were around 145 Fahrenheit. (~25 degree drop)

I repeated this test the next day, with and without the compound, and I slashed 20 degrees Fahrenheit using it.

Something I am definitely going to stick with throughout the summer months.
 
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L3phturn

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The #1 thing that drives motor temps is gearing. What pinion are you running? Did your kit come with 2 of them? What surface are you running on?

Before you bother with thermal paste and a heatsink and fan you need to peel the label off of the can, but I suspect you did that.

How hot is it running exactly? I presume you have an infared contactless thermometer. As long as you stay under 170 F you should be fine.
 

WIZARDRC

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The #1 thing that drives motor temps is gearing. What pinion are you running? Did your kit come with 2 of them? What surface are you running on?

Before you bother with thermal paste and a heatsink and fan you need to peel the label off of the can, but I suspect you did that.

How hot is it running exactly? I presume you have an infared contactless thermometer. As long as you stay under 170 F you should be fine.
Yeah I'm running stock gearing which admittedly on the 3s models with the stock motor mount, the mesh is a bit tight. This definitely doesn't help with temperatures.

And regarding the label mine didn't come with one :oops:

Precisely what I am using to measure temperatures. I tend to record them after a battery long run. Without the compound depending on the day it ranges from 170-180, with the compound its ranged between 145-155. (Fahrenheit)

I figured anything 170-180 is safe, but I found this was a relatively simple solution and wanted to share it in case anyone was experiencing overheating during the summer or generally just wanted some lower temps.
 

L3phturn

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Oh yeah brushless usually don’t have labels.

170-180 is too hot.

That is what we really needed toknow, Arctic silver, heat sink and fan dropped temps 25 degrees. That’s excellent- takes it from borderline to safe. 👍
 

WIZARDRC

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Oh yeah brushless usually don’t have labels.

170-180 is too hot.

That is what we really needed toknow, Arctic silver, heat sink and fan dropped temps 25 degrees. That’s excellent- takes it from borderline to safe. 👍
Perfect if you or anyone that reads this thread tries this out, post your results with what rc and motor you're running. Would be interesting to see results from numerous people!
 

L3phturn

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Perfect if you or anyone that reads this thread tries this out, post your results with what rc and motor you're running. Would be interesting to see results from numerous people!
So far the brushless motor I put in my Volcano has fins on the can and isn’t suitable for a heat sink. But I will test and publish when my Notorious eventually arrives. If it does. Someday. 🤦‍♂️
 

jondilly1974

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Thermal grease will dry out at some point. Once it does it becomes an insulator. Until then it’s a dirt magnet. I understand the reason you think it would be a good idea. A better idea is a proper sized motor with proper gearing. No more heat issues.
 

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