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  1. #1
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    All my motors dies after a month!!

    Hello, i've had an e-maxx for a while and first i had the original 550's and after while they died so we got some new, they also burned up or what ever happend to them, I think ive had to replace almost 6 new motors because they just keeped dying. So after a year i bought the kershaw designs 700 ho (works great) but then they also stoped working but after a longer time. So I got some new ones and they have just started to die. they are smoking and smells like burned electronics..

    I dont want to buy anymore motors because i dont know what the problem is. why does all my motor die so quick? they die at the same time..
    Please give me some answers of what i could be.

    Thanks

  2. #2
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    Not breaking them in, i had this problem with my 2 rustlers and my 2wd stampede, although those motors i have in them are the titan 12t 550, I Burned through them within a few batteries, and also i noticed they dont like LI-PO batteries. i can run my NI-MH, NI-CD batteryies all day, i put my 2s LI-PO 7600 MaH and it baked it in about 7 minutes. HOPE THIS HELPS :]

  3. #3
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    I have breaked in all the 700 ho motor but still they die..
    How long should motor last? but i dont think they die at the same time..
    I Use nimh battery i think, im sure its not Lipo.

    thanks

  4. #4
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    Go brushless...

  5. #5
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    Maybe your gear mesh is too tight and it's causing high heat and resistance in the motors.

  6. #6
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    Quote Originally Posted by macz View Post
    Go brushless...
    Maybe but still i want to know the problem because it's a bit more expensive to go brushless and I still want it waterproof.

  7. #7
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    Quote Originally Posted by M n M View Post
    Maybe your gear mesh is too tight and it's causing high heat and resistance in the motors.
    I dont think so, I had a some paper between the gears so i dont think so.

  8. #8
    RC Turnbuckle Jr. humayrayakongkinaon's Avatar
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    with all the motors that you bought and the KD kit, you could have buy a good BL system, atleast you dont have to break-in the bl motor. sorry to say this but i think you overworked your motor, whats your gearing?
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  9. #9
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    Have you been cleaning and oiling them, after you ran the truck, they need proper maintenance to extend their life.

  10. #10
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    I got the 550 motors becasue the car was new.
    I didn't clean that much.. not much at all but i still think it should last longer then they did.
    I had the orignial gearing with the 550 and i dont know what i had on the 700ho but kershaw designs said it was the best for the car.

  11. #11
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    Maybe your driving style? Lipo can stress a motor, simply because the lipos have more to offer, so the motor draws more. That being said, 700-HOs usually last several years, and at least 200 runs. However recently I havnt been hearing the best about KD, but Dan is usually good with warranty, so he may give you at least half credit on a new set or a brushless...

    If you are a hard driver and you pop lots of wheelies or do alot of water running/mud running, your motors will suffer. Did you have dual or single 700-HO?
    Doublethink: 2+2=4 while 2+2=0

  12. #12
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    If you put big jumbo tires on it without gearing for them, that can stress a motor to the point of breaking.

  13. #13
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    Hey Fiskarn, I have many questions that may help the guys:

    •Where do you usually bash?
    ie: Dirt, rocks, sand, street, long/short grass... Lol, post a pic from Google Earth
    •What pinion & spur are you running?
    •What batteries are you using?
    •Do you drive through water or mud?
    •Do you jump your truck?
    •Are you still using the stock Esc?
    •How tight do you run your slipper clutch?
    •Do you check motor & Esc temps after runs?
    •What tires are you running?
    •Do you tow or pull with your truck?
    •In replacing motors, did you change the motor wire connecters?
    •*Truth time* What are your 'bad' driving habits?
    ie: Wheelies, backflips, 'reckless' speeding, lol Haha

    I think that should get us started

    Quote Originally Posted by PowerToTheMaxx View Post
    ...but Dan is usually good with warranty, so he may give you at least half credit on a new set or a brushless...
    +1

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  14. #14
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    where do you store the truck when not being used.
    Guide books aren't part of the packaging.

  15. #15
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    no offence but your motor problem sounds like my nephews exact same problem. his problem is that rcs only have wide open throttle.

    better to go brushless.
    Last edited by ajcar; 09-22-2012 at 07:08 AM.
    I'm not krazy. My mother had me tested.

  16. #16
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    I usually fleebay the stock brushed and go brushless..

  17. #17
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    Okay, how i drive well I like to stand still and go full throttle for a wheelie but ye its not the best for the motors.
    I mostly drive on my lawn and on the road(gravel road) or in the forest but i never go full throttle when I'm in the forest there i just go slow adn kinda like crawl.
    Doesn't the motors like it if u push the throttle to much?

    I have the car in my garage when i dont drive and i always clean the car after a run but not inside the motor with oil and everything.

  18. #18
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    Quote Originally Posted by Little Smokey View Post
    Hey Fiskarn, I have many questions that may help the guys:

    •Where do you usually bash?
    ie: Dirt, rocks, sand, street, long/short grass... Lol, post a pic from Google Earth
    •What pinion & spur are you running?
    •What batteries are you using?
    •Do you drive through water or mud?
    •Do you jump your truck?
    •Are you still using the stock Esc?
    •How tight do you run your slipper clutch?
    •Do you check motor & Esc temps after runs?
    •What tires are you running?
    •Do you tow or pull with your truck?
    •In replacing motors, did you change the motor wire connecters?
    •*Truth time* What are your 'bad' driving habits?
    ie: Wheelies, backflips, 'reckless' speeding, lol Haha

    I think that should get us started



    +1

    Dan is the BEST!
    I usually run on grass or gravel road and thats when i go full throttle. otherwise i take it easy if its in the forest or something.
    I have everything original expect the two 700 ho and the gears on them. i tihnk it's 2-5 over original.
    I got some nimh 4000 mah 8.4 v batteries.
    I drive through water but then it's slow and kinda crawl speed same with mud.
    i dont jump truck that much.. not any big things or so.
    I have the original ESC yes.
    I have a piece of paper between the gears when i install the gears.
    Yeah i feel them after every run and they are a bit hot.
    original tires.
    Nope no towing or pulling.
    i have had new wires every single time.
    My driving is mostly wheelies, speeding aggresive driving on gravel road so the gravel flyes all over the place.

    Thank you for taking your time everyone.

  19. #19
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    motors don't like a lot of use of the brakes but dust is a life shortener. The life of the 550's vary from weeks to over a year, just from what i read. I pretty much swapped mine straight out for the dewalt.
    Guide books aren't part of the packaging.

  20. #20
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    Quote Originally Posted by trax de max View Post
    motors don't like a lot of use of the brakes but dust is a life shortener. The life of the 550's vary from weeks to over a year, just from what i read. I pretty much swapped mine straight out for the dewalt.
    Dewalt? you mean that you bought a bigger brushed motor? If can send me which one.

  21. #21
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    yea. I haven't seen the code for this motor in any tool shops, but the popular number code for other dewalt motor is 396505-21. There is about six different codes but this one is maybe the easiest to find or pick up.
    Or pick one up from Kershaw designs.
    Guide books aren't part of the packaging.

  22. #22
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    Quote Originally Posted by trax de max View Post
    yea. I haven't seen the code for this motor in any tool shops, but the popular number code for other dewalt motor is 396505-21. There is about six different codes but this one is maybe the easiest to find or pick up.
    Or pick one up from Kershaw designs.
    I don't know i live in sweden it takes long time for the shipping but what can i do. if i want brushless will 2 8.4volt niimh work for it? i mean is it a big diffrence between lipo and my batteries. how many watts?

  23. #23
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    I've never had a brushless motor. But for the dewalt if you check there site dewalt.se and search for a service agent in sweden you could buy one from there which will save shipping costs. Looks like there is seven repair centres to choose from.
    Guide books aren't part of the packaging.

  24. #24
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    If you decide to go BL, you'll only need one motor.

    With a BL motor the difference between NiMH and LIPOs is night & day. Most BL motors don't like water, luckily waterproof BL motors are available.

    2s LIPOs are 8.4v, 3s jumps to 11.1v. LIPOs dont like water either, some people put the battery in a balloon, there are a few ways... One of the nice things about LIPOs is they give 100% power up till they are ready for a charge, unlike NiMH that peak quickly, then fade until they die.

    Dont want to hijack, I have a single question that I feel doesn't really warrant a new thread. The stock BL motor in my 1/16 Merv 7107 stutters and hesitates upon acceleration from a stop. The owners manual says this is normal. Don't get me wrong, BL is the way to go. I like to crawl, do the 1/8 BL motors do the same thing?
    Last edited by Little Smokey; 09-22-2012 at 06:16 PM.
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  25. #25
    RC Turnbuckle Jr. humayrayakongkinaon's Avatar
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    Quote Originally Posted by Little Smokey View Post
    Dont want to hijack, I have a single question that I feel doesn't really warrant a new thread. One thing that concerns me; the stock BL motor in my 1/16 Merv stutters and hesitates upon acceleration from a stop. Don't get me wrong, BL is the way to go. I like to crawl, do the 1/8 BL motors do the same thing?
    you talking about cogging? its normal for a sensorless BL motor.
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  26. #26
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    Quote Originally Posted by humayrayakongkinaon View Post
    you talking about cogging? its normal for a sensorless BL motor.
    Cogging, yes. So look for a sensored BL motor, thanks!
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  27. #27
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    well i think i will go for a new pair of 700 ho's because they are good and im soon gonna sell the car.
    but i want to know why my motors die so fast..

  28. #28
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    I hear you. From the info you shared, there's not much to finger. So... Here are a few things that will kill a brushed motor:

    •excessive heat
    •sand
    •dust/dirt
    •salt water
    •too many amps from the ESC
    •lack of maintenance (includes bearings)
    •resistance in the drive line
    •improper gear meshing

    Guys & Girl Chime in with other reasons
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  29. #29
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    1st thing I would do is take the pinions off the motors and make sure the truck rolls perfectly smooth. If the truck isnt binding up at all you are just driving them to death.

  30. #30
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    HobbyWing makes a waterproof ESC (SC8WP). The high torque combo is about $150.00 and you'll be amazed at how well it runs.

    About the cogging. I have a 1/16th MERV and it also coggs very bad. Part of it is the motor is only a 2 pole. I have a 4 pole motor in a 1/10th scale R/C and it coggs much less. My E Maxx is running a 6 pole motor and it's as smooth as a sensored motor. So if you want a sensorless motor that ramps up like a sensored motor get a high pole count or just go sensored.

  31. #31
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    That's good to know, thanks LD
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  32. #32
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    Quote Originally Posted by Little Smokey View Post
    I hear you. From the info you shared, there's not much to finger. So... Here are a few things that will kill a brushed motor:

    •excessive heat
    •sand
    •dust/dirt
    •salt water
    •too many amps from the ESC
    •lack of maintenance (includes bearings)
    •resistance in the drive line
    •improper gear meshing

    Guys & Girl Chime in with other reasons
    Incorrect gearing, but i think that's been said higher up. The motor draws what it needs. Too high and it will draw more current. when stressed. Using on road gearing for off road for example.
    Guide books aren't part of the packaging.

  33. #33
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    Well if i buy brushless i think 150$ is good but how many watts will the motor give with two LRP hyper pack 4000 nimh 8.4v = 16.8volts? will 2 7 cell battieries be to much for a ezrun 120a? the waterproof one.
    I want more power then 2 700 ho's if its brushless.
    Last edited by Fiskarn; 09-23-2012 at 05:18 AM.

  34. #34
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    I just checkled the car and i think the pinion was 25t! atleast 23-27t somewhere but is that much for 2 700 ho's?
    also the motors are working but as soon as u work them a little bit thye start smoking. and i think my transmitter or reciever or broken because it goes forward or backward all the time and doese things of it self.

  35. #35
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    do you have a 2.4ghz or a old AM/FM radio?
    Doublethink: 2+2=4 while 2+2=0

  36. #36
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    Old AM/FM 27 mhz.. i know, but i dont want to spend so much money.. i am going to get 2.4ghz.
    I've heard that brushed motors doesn't last long at all, some say jsut for 30 runs or something, is that true? so i've been thinking of buying brushless now..
    From kershaw designs the Leopard SC8 120A 4S Waterproof ESC with the Leopardbrushless motor 4074.
    How many watts do you think i can get with my 14 cell 16.8v batteries?(2 7cell together)

  37. #37
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    Flysky sells 2.4ghz transmitters and receivers for $20 each. They have a very good rep. How mah on those batteries?
    Doublethink: 2+2=4 while 2+2=0

  38. #38
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    Quote Originally Posted by PowerToTheMaxx View Post
    Flysky sells 2.4ghz transmitters and receivers for $20 each. They have a very good rep. How mah on those batteries?
    its 2 LRP hyper pack 4000 mah 8.4v , gonna use 2 of those togwether which is 16.8v
    also i ahve had a HBX monster bonzer or something(first car) and that motor is still working soon 5 years or something. I have had it under water and everything..

  39. #39
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    Quote Originally Posted by Fiskarn View Post
    Well if i buy brushless i think 150$ is good but how many watts will the motor give with two LRP hyper pack 4000 nimh 8.4v = 16.8volts? will 2 7 cell battieries be to much for a ezrun 120a? the waterproof one.
    I want more power then 2 700 ho's if its brushless.
    The SC8 isn't rated for 14 cells, only 12 cells. It might work but it puts a strain on the BEC.

    It will have more power than two 700HO's only running 4s lipos. If you can check out some videos on YouTube you'll see what you can expect.

    Part of the glitching problem is the brushed motors with the AM 27mhz. Brushed motors are hard on the radio system when new and are a big problem when they get worn as your finding out.
    2.4 or FM is a much better option.

    RCECHO has the system you mentioned cheaper than Kershaw. You might be able to still use this code for a wish2012 for another 5% discount.

  40. #40
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    well i think i have decided, i will go for 2 new 700 ho and check up my radio system. I'm going to sell the carry anyway so not worth it to buy BL. I will just run the car while it's for sale.

    thanks

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