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  1. #1
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    Dewalt e-Revo - Heat issues please help

    Hi guys, I just switched my e-revo over to the dewalt this weekend.

    I am not sure what is considered acceptable temps. After 5 minutes of somewhat hard play my evx2 and motor were so hot I could only touch them for 3-5 seconds air temp was 73F (indoors where I played).

    Here's the specs.

    I bought a new 12v motor (old style) from ebay did all the mods to make it fit.

    Water breakin (2C bats till dead)
    Cut off the ears
    Made 1/8" aluminum spacer
    Soldered 2 power leads on each brush (no loose leads on evx 2)
    Soldered on 3 - .1 Caps
    21t - Pinion
    68t - Spur

    The pinion spur combo is pretty tight for the mounts. I either have to change the spur smaller or modify the motor mount to allow for larger adjustment.

    I am running this on a couple 7 cell MiMh packs. Which were also really hot (could smell the heat)

    Are my heat issues related to my packs not being able to sustain the amount of discharce the dewalt is asking for? I have a couple of GensAce 5000mah 2S 40C LiPo bats that I havent ever used. I needed to hook up the LVC first.

    I intend to go brushless when the snow clears off. But I need a brushed setup too so I can enjoy this car year round since it's snowy for 5+ months of the year here.

    Any advise is welcome.

  2. #2
    RC Turnbuckle Jr.
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    Jul 2010
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    21/68 is too much for a single dewalt I would have said, hence your high temps- gear down to 18/68 and take it from there.

    As for temps, I would say esc and motor shouldnt excede 160*F ideally, batts no higher than 140*F maybe ( not sure how sensitive to hear nimhs are compared to lipos, but they shouldnt be too hot to hold at any rate ).

    Your esc and motor wouldnt heat up if the batts couldnt provide the current, the batts would simply overheat and pop ( literally ). If the motor and esc are hot, then they are getting the current the motor is trying to draw, but it is drawing too much as it is overgeared/ overworked > gear down and esc/motor/batt temps will drop
    Keeping the Mods busy is my specialty...

  3. #3
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    Feb 2011
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    Thx for the advice.

    Is 21/68 always too high? I was horsing around with the power by pushing my 30lb son around on an office chair and slamming him into the wall.. :-) was very fun! But maybe I was putting too much strain on the drive?

    Is 21t to 18t that much of a difference? Not arguing, just trying to learn.

  4. #4
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    Feb 2011
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    18t ordered.

  5. #5
    RC Turnbuckle Jr.
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    You were towing a 15kg lump of meat too? go figure the electronics were overheating...

    Assuming you kep everything else the same, then each tooth on the pinion is worth 2-3mph with 4s lipo/ 12/14 nimhs, so 3 teeth can make quite a difference, especially if the system is loaded up a fair bit. Experimenting is the key though really- if you can fit the smaller ( 65 & 62 ) spurs then you have a nice range of gearing options to play with and record temps, to see which gives the best results in any given situation..
    Keeping the Mods busy is my specialty...

  6. #6
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    Quote Originally Posted by ArmyofDarkness View Post
    You were towing a 15kg lump of meat too? go figure the electronics were overheating...
    Yes, I forgot to include that....and yes I am dumb... hahaha

  7. #7
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    I ran it last night outside without 15kg of meat and 21/68 gearing. During a quick yet hard 7-8 minute run the motor shell was completely touchable as was the esc. I did bump the brush with my finger which was very hot, but I think that's probably to be expected. The LiPo bats weren't even remotely warm.

  8. #8
    RC Racer
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    your problem was the strain you put on it, and more then likely going slow the whole time so no real airflow to cool things down, heck of a work out you put on it. I would not do that again with out gearing it way down
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  9. #9
    RC Turnbuckle Jr.
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    21/68 for normal use then, 18/68 when towing the kids around or driving through seom seriously heavy terrain.

    I dont have a kid to tow around myself, but I do have a ~4month old nephew; I'll give it a little while before I start towing him behind the Gmaxx...
    Keeping the Mods busy is my specialty...

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