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Old 03-26-2009, 01:24 AM   #1
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Default Freeze my brushless motor?? - any advantage??

Ive got this huge home-made motor freezer that the OGs at the track told me they used to use on brushed motors to bring the temps down before a race ( I guess it would buy them a minute or two before the cooked their motor with tall gearing). Would this same principle apply to a brushless motor - how come I dont see people using these on brushless motors?
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Old 03-26-2009, 01:56 AM   #2
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This is a good question! I remember the Pan car guys used to do this back in the day.

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Old 03-26-2009, 02:31 AM   #3
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I used to freeze my brushed motors. I switched to brushless and also used the freezer on my first 6.5. It lasted 4 or 5 runs before it seized up. I think the problem is due to what gets cold. A brushed motor would get cold magnets (on the can) whereas a brushless motor gets cold coils. I suspect the sudden change in temperature of the coils does something with the condensation levels and probably causes shorting out which leads to an overheat. I've heard people suggest the moisture played up with the sensors causing the timing to go funny, but that wouldn't explain my problem because I was running sensorless.

In summary, I wouldn't risk freezing another one of my brushless motors.
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Old 03-26-2009, 02:55 AM   #4
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i saw hara freeze his BL motor during TITC in thailand last month....
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Old 03-26-2009, 03:02 AM   #5
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That's because Hara gets his stuff FREE! LOL

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Old 03-26-2009, 05:17 AM   #6
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That's because Hara gets his stuff FREE! LOL

Jay
NO.... he gets money for using that stuff!!!
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Old 03-26-2009, 05:55 AM   #7
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Well that's even better than free... that's free money!

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Old 03-26-2009, 07:03 AM   #8
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We had a bunch of people doing it at our outdoor track and a bunch of motors failing. We suspected perhaps the freezing was doing it so everyone stopped and the motors stopped failing.
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Old 03-26-2009, 07:20 AM   #9
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I've seen batts frozen too.
And I have heard about Buffalos jumping off the edge of a cliff.
Lots of things you can do if you plan on throwing it away when the run is over, and a lot of things you shouldn't do if you plan on using said part again.
I think it was Mike Reedy that once said, "If we thought it was a good idea we'd send them packed in dry ice. What you decide to do with it after you get it from us is up to you, just don't send it back to us when you blow it up."
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Old 03-26-2009, 07:24 AM   #10
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Try a google search on the "Mpemba effect". You would be surprised that warm water can freeze faster than cool water! It's true. If you apply that theory in reverse to motor cooling, it could be that the cooler motor heats up faster?
It's common to hear people talk about motors overheating after cooling them first. I can't see how a little bit of miosture on the surface after cooling could be the cause.
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Old 03-26-2009, 07:37 AM   #11
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I've heard stories of people using the much more therocooler thingy and it's got the motor down to a point where moisture has built up inside the can and moisture on the sensors.. rendering them useless.
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Old 03-26-2009, 08:15 AM   #12
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I've heard stories of people using the much more therocooler thingy and it's got the motor down to a point where moisture has built up inside the can and moisture on the sensors.. rendering them useless.
Correct, a bit of moisture in a brushed motor will soon evaporate, but in a brushless the moisture is a bit more trapped and of course it contains electronics.

I used the Much More cooler for a while but gave up as if it was left running for more than 5-10 mins before a race I got bad stuttering during the run.
Next run I wouldn't use the cooler and wouldn't get stuttering.
I tried this a few times over a few months.

Just fit a decent motor/fan heatsink to the motor like the Nosram/LRP unit.

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Old 03-26-2009, 08:31 AM   #13
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Try a google search on the "Mpemba effect". You would be surprised that warm water can freeze faster than cool water! It's true. If you apply that theory in reverse to motor cooling, it could be that the cooler motor heats up faster?
It's common to hear people talk about motors overheating after cooling them first. I can't see how a little bit of miosture on the surface after cooling could be the cause.
Haha, yeah heard that one, an old builders trick apparently for warming up their hands :P
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Old 03-26-2009, 10:22 AM   #14
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Quote:
Originally Posted by Pablo Diablo View Post
Try a google search on the "Mpemba effect". You would be surprised that warm water can freeze faster than cool water! It's true. If you apply that theory in reverse to motor cooling, it could be that the cooler motor heats up faster?
It's common to hear people talk about motors overheating after cooling them first. I can't see how a little bit of miosture on the surface after cooling could be the cause.
Nope.. the Mpemba affect doesn't have anythign to do with warming, thawing, or heating up.
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Old 03-26-2009, 10:35 AM   #15
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In my opinion it helps, I've messed around with a MM cooler, and it appears to help lap times in the first few minutes. However, it is NOT allowed at ROAR sanctioned events.
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