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Old Mar 21, 2010, 09:22 PM
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Sturgis, MI
Joined Oct 2009
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How hot is too hot for the ESC and Brushless motor?

I checked the temperatures on my esc, motor and batteries the other day after a good run. The motor was 225 deg F, the esc was 140 deg F and the lipo batt was 110 deg f. Was just wondering what temperatures are acceptible? I'm running a 1/10 scale Traxxas Slash, 4 wheel drive, with 3s 25c 5000mah lipos. The ESC is the Traxxas Velineon VXL 3S with the Velineon 3500 brushless motor. Are these temps ok or should I change gearing to keep the motor cooler? I'm still a newbie and the motor just seems really hot at 225...
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Old Mar 21, 2010, 09:49 PM
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225 is way too hot............i try to use the 5 second rule...........can you put your finger on the motor for 5 seconds? At 225 im gonna say about half a second............. Probably as farenheit numbers go, 150 or less outta be ok. Esc should be 120 or less IMO........batts are on the high end at 110*. You need to gear down several teeth on the pinion. If you are at 21 try 18 etc............
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Old Mar 21, 2010, 10:35 PM
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Most companies recommend no higher than 200 deg on the motor.
Most racers will suggest that BL motors really perform their best on the warm side, 150 as a minimum.
Batteries it's hard to say, as LiPOs run cooler than NiMH and it's hard to compare from pack to pack as a lot of the heat comes from the internal resistance in the pack/cells.

But as scorpion suggested, "use the 5-second rule" as a good rule of thumb for quick checking the motor temp.
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Old Mar 22, 2010, 02:54 PM
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Sturgis, MI
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Quote:
Originally Posted by scorpion1 View Post
225 is way too hot............i try to use the 5 second rule...........can you put your finger on the motor for 5 seconds? At 225 im gonna say about half a second............. Probably as farenheit numbers go, 150 or less outta be ok. Esc should be 120 or less IMO........batts are on the high end at 110*. You need to gear down several teeth on the pinion. If you are at 21 try 18 etc............
It came with a 13 tooth pinion installed and an optional 18 is also included. I assume putting the 18 in would make things hotter...
Any other suggestions on how to cool it down?
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Old Mar 22, 2010, 03:50 PM
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........
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Old Mar 22, 2010, 04:41 PM
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Wth?


Gearing up so much on the pinion is sure to make things hotter.
Try gearing down some on the pinion.
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Old Mar 22, 2010, 09:02 PM
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Sturgis, MI
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Originally Posted by rocketmtrspts View Post
Stop using the 3S battery, which is totally unneccessary, and obtain a 2S pack.
Is using the battery for a few minutes after the low voltage warning cuts in causing it to get so hot? I hate to buy new batteries, I get 30+ minutes run time from these batteries (3s 25c 5000mah) whats the differnece between 2s and 3s... Its so fast with the 3s and so much fun...
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Old Mar 31, 2010, 11:04 AM
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United States, CA, Orange
Joined May 2007
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using the battery after the low voltage is whats getting your battery hot
ur lipo wont last if you keep doing it

try cutting holes in the shell for cooling and you can try installing the Traxxas Velineon ESC Cooling Fan (TRA3340)

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Old Mar 31, 2010, 12:48 PM
Under Warranty!
2sicMiniT's Avatar
Washington State
Joined Feb 2006
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What's the deal with the low voltage warning? Usually it disables the car, you should not be able to use it once it kicks in. Are you sure you arent confusing it with temperature shutdown?

Sounds like there is something going on with the gearing. You are only pushing 125A of 200A constant. So you aren't over powering it. The only other thing I can think of is your battery leads/wires. Make sure they are not too small. Feel your wires to make sure they are not hot, if they are then there is a bottleneck.
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Old Apr 02, 2010, 04:36 PM
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what color is the LED on the speed control?
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Old Apr 08, 2010, 09:09 PM
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Thanks everyone for the suggestions, I havn't run it in a few weeks, hopefully will get some time to play this weekend and report back then. I did get the cooling fan for the ESC.
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Old Apr 08, 2010, 11:01 PM
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Quote:
Originally Posted by JLH Racing View Post
Thanks everyone for the suggestions, I havn't run it in a few weeks, hopefully will get some time to play this weekend and report back then. I did get the cooling fan for the ESC.


Cooling fans were first used and primarily intended for Touring Cars and Buggy's, whose aerodynamics and/or body design inhibits any air getting to the electronics.

So keep in mind that a cooling fan in your case is really just a quick-fix, that in many cases if you're running that hot to use a fan to keep it running you're really just applying a band-aid. Optimally, an ESC/motor should be able to operate just fine without an excessive cooling measures.
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Old Apr 09, 2010, 12:42 AM
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cooling fans are usefull in any vehicle, some more than others. but still, a cooling fan will help a little, i've heard they only bring things down 1-5 degrees farenheit, not much but every bit counts. now multiple cooling fans and a big heat sink will help, on my next sc shell i'm gonna set it up with cooling fans where the fake ones would be, and route pipe to the motor, the esc already has one. should help a little on the cooling bit, allowing me to push it a little more. the only other thing i can think of that is causing your problem is the wire or your battery isn't giving out enough power. but the battery thing isn't likely. the wire could be. see if you have any really small wire and as said, check wire temps. they will tell you if the wires are an issue.
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Old Apr 09, 2010, 07:34 AM
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It's like taking a super heated metal item and blow on the outside.
What temperature is the INSIDE, where the guts of the operation are working. Bringing down the temps on (the outside) of something 200-degrees by 2-degrees with the use of a fan is still only a 1 percent change.
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Old Apr 09, 2010, 10:04 AM
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yes. but every little bit will help.
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