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  1. #1
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    MM ESC fan issue, I think.

    Today i drove my truck for real for the first time, It's all dirty and crap now. But i was going through grass and over big piles or dirt and just haveing fun with it and my ESC fan did not come on at all. From the time i turned my ESC on to the point i turned it off and i ran it for about 25min. My ESC was warm, It did not fell burning hot but it was pretty warm and i just have no idea if the fan is saposed to be on all of the time. I just want to know so i know if my ESC has a fulty fan plug or if my fan is broken. I can wire a new fan to plug into the RX but i dont want to if i dont have to.

    Thanks for any help and info.

  2. #2
    RC Turnbuckle Jr. humayrayakongkinaon's Avatar
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    fan will only come on when you plug the batt and shuts off...... will come on again only when the ESC gets hot i think 150 degrees(?)
    | Rally GT8 Powered By CC |

  3. #3
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    Oh, Thats wierd. I would think 150 is too hot. I might maybe just put a JST plug on and extend the fan wire to plug into a open port on the RX. That way my ESC will be cool all the time and the fan will run a 5v. If thats the case though with the MM ESC i will for sure do that.

  4. #4
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    150F is fine, my laptop will do 180F on heavy load.

  5. #5
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    Thats crazy, I thought the ESC would burn up at 120*. I might still mod my fan just for the peace of mind, But i dont know yet.

  6. #6
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    I use the muchmore racing 30x30 rev type fan. They have a higher rpm than the castle ones, and i plug mine into a y- harness with the esc. I found that a bec set at 6.4 volts is perfect for the rpm of the fan. Muchmore racing's customer service is awesome also; they sent me 6 replacement fans, no questions asked.
    I reject your reality and substitute my own!

  7. #7
    RC Turnbuckle Jr. 87 GN's Avatar
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    Hot motor + cool esc = under geared.
    Cool motor + hot esc = over geared
    Everything warm just right..

    Motor ~ 180/190*F (82/88*C) maximum, ideally 140/160*F (60/71*C), temps can be 10*F higher inside the motor
    ESC ~ pretty much same temps / Fan comes on @ 150*F (65*C)
    Lipo's ~ 140*F (60*C) max, ideally 100/120*F (38/49*C).........
    Would you go flip my truck back over??

  8. #8
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    Quote Originally Posted by 87 GN View Post
    Hot motor + cool esc = under geared.
    Cool motor + hot esc = over geared
    Everything warm just right..

    Motor ~ 180/190*F (82/88*C) maximum, ideally 140/160*F (60/71*C), temps can be 10*F higher inside the motor
    ESC ~ pretty much same temps / Fan comes on @ 150*F (65*C)
    Lipo's ~ 140*F (60*C) max, ideally 100/120*F (38/49*C).........
    Do you know what the best gearing it? I am useing 18T/54T. But soon i will use 21T/54T so i dont know if that setup it good.

  9. #9
    RC Turnbuckle Jr. 87 GN's Avatar
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    I run 21/54 with 2/2s

    what is yor cell count??
    Would you go flip my truck back over??

  10. #10
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    Same as yours, I use 2x 2s 7.4v 4400mah packs, For a total of 4s.

  11. #11
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    Quote Originally Posted by 87 GN View Post
    I run 21/54 with 2/2s

    what is yor cell count??
    Are you running stock wheels and tires?
    ERBE, MERV BB

  12. #12
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    I am not useing the talons, But i am useing the Revo 3.3 5309 wheels and tires.

  13. #13
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    Also waht 21T gear do i need? I bought one before but it was WAY to big. So i need one to mesh with the stock 54T plastic spur gear.

  14. #14
    RC Turnbuckle Jr. MITCH316's Avatar
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    You need a mod 0.8 gear for 5mm shaft or 32 pitch.
    Rock n Rolla !

  15. #15
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    Will this fit? http://www.ebay.com/itm/Traxxas-3951...#ht_2658wt_910 It's so cheap i think it's not going to fit.

  16. #16
    RC Turnbuckle Jr. MITCH316's Avatar
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    That's for a 3mm shaft mate...you need this one http://www.ebay.com.au/itm/Robinson-...item20cd89cbe6
    Rock n Rolla !

  17. #17
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    Thanks, I knew that other one was not the correct size, I was just not sure what one to get. I order that gear right now.

  18. #18
    RC Turnbuckle Jr. 87 GN's Avatar
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    Tires 3.8 Badlands....


    what is the C rating of the 4400 mAh??

    might keep your gearing conservative if your batts are not up to the 120 amps min.....


    MY BATTS:
    2S 9000 x 28C = 252,000 divide 1000 = 252 amps
    2S 8000 x 28C = 224,000 divide 1000 = 224 amps
    3S 5200 x 40C = 208,000 divide 1000 = 208 amps
    2S 4700 x 25C = 117,500 divide 1000 = 117.5 amps
    ^I run in my Summit.. ^ Requires proper gearing^


    ( mah x c rating / 1000 = amps)

    The
    more amps the better / minimun of 120 amps.

    The ESC will only draw the amount of amps it needs.

    Higher the mAh the longer the runtime.
    For brushless systems 8000 mAh about 45 min & a 5000 mAh about 30 min.
    Times are longer for brushed systems.


    Batts in series double the voltage:
    2x 2s 20c 5000mah = 4s 20c 5000mah

    Batts in parallel double the mah capacity:
    2x 2s 20c 5000mah = 2s 20c 10,000mah.
    Would you go flip my truck back over??

  19. #19
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    40C with an 80c burst. Per pack.

    You really have me After all that. I use 2x 2s 40c 7.4v 4400mah packs. What kind of run times should i see with the 21T/54T? I am going to just put the 21T pinion in with the 54T spur and keep it like that. I dont want to have to change gearing for bigger batts. And why are runtimes longer on brushed systems? I thought brushless had better runtime. Brushless probably has all around better performance.
    Last edited by JohnnyT1992; 11-18-2012 at 09:46 PM.

  20. #20
    RC Turnbuckle Jr. 87 GN's Avatar
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    Brushed does not take as much mAh to power....

    Easy on the throttle maybe 30 min, hard on the throttle 20 min......

    You don't have to change gearing with bigger batts (mAh). You might if you are changing the cell count.
    Would you go flip my truck back over??

  21. #21
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    Geez, 20min. I thought i would get a good 35min or so. I need those 9000mah packs. lol And i only do plan to run 4s. I think 6s is just stupid crazy. Thats when things start breaking. I'm glad i found that out now so i dont go and overdishcharge my packs.
    Last edited by JohnnyT1992; 11-18-2012 at 10:06 PM.

  22. #22
    RC Turnbuckle Jr. 87 GN's Avatar
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    you did set the LVC?? I run mine at 3.5v per cell.......
    Set yours at 3.4v per cell... difference of a few min...
    I can run 30~40 min & still have 3.85 ish. Varied throttle control.....
    Last edited by 87 GN; 11-18-2012 at 10:14 PM.
    Would you go flip my truck back over??

  23. #23
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    yeah, its set to 3.4v. So the Once the packs get to 3.4v the ESC will turn off? I forgot about LVC, I never seen it kick in. And dose it hurt the pack letting it go into LVC all of the time?

  24. #24
    RC Turnbuckle Jr. 87 GN's Avatar
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    well JMHO...cheaper off brand Batts yes, they warm up at the end of the run...

    You will know the LVC has kicked in when you only have 1/4 power at full throttle.....

    One reason I only run my batts to 3.85 ish, that is the storage volts for anything more than a few days without cycling the batt..
    & after running for 30~40 min I am ready to call it a run. I live in the county & have my jumps, berms right out the back door....lol
    Would you go flip my truck back over??

  25. #25
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    Thanks for the info, I dont let my ESC go into LVC i try to keep it around 3.80 or so. I need to storage charge my batts now. I dont know when i will run my truck again. How do i storage charge my packs? I never did that before.

  26. #26
    RC Turnbuckle Jr. 87 GN's Avatar
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    Some charges have a storage charge mode, they will either charge up the batt or discharge the batt.

    If your charger doesn't have this option, run the truck to bring the Volts down, then put it on the charger & watch as the volts are brought back up to the 3.85 ish....
    Would you go flip my truck back over??

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