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  1. #1
    RC Racer
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    4s with 17t pinion or 20 to offroad? How to set up esc for lipo?

    Hi. I got a Emaxx brushless 3908 pre waterproof.

    I have reed the manual and i cant find things about lipo program and nimh.
    The traxxas paper that came inside the body out of the box says this model is set up for lipo, but the stock battery is nimh, do they mean that the esc is on lipo mode and we still could use nimh?
    How can i find out that is ready for lipo with lipocut? And could i use nimh if esc are setup for lipo?

    The other question is about gearing.
    Manual show a lot of gear about whats fit or not with different gears and battery.
    They mean that 4s and stock gears dont fit?
    Could i mount the optional 20 pinion and use it on grass and offroad runs in the woods without get to hot motor and esc?

    Thanks if someone have time to answer me :-)

  2. #2
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    I believe the ESC has auto detect. So when you upgrade to lipos it should detect what your running and then how many cells. It will do a tone followed by so many beeps, each beep is one cell so on your 4s it should beep 4times. The auto cut off for the lipo is default 3.2v which is safe but I bumped mine to 3.4v.

    You may want to consider the field link programmer. I bought it and it comes in handy, allows you to set all settings and read settings in the ESC.

    As for the pinion, run it as long as you have a temp gun and can monitor the motor temp. I cunnrently have the 17,18,20 but running the 18. Haven't put the 20 on yet. But just watch your temp

  3. #3
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    I have a 20t pinion in my maxx right now.Temps on the motor the other day top out at 123*. Outside temp was in the 50s.
    I see alot of people running the 20t pinion with good luck. I do have a 18t if need be.

  4. #4
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    Thanks buggybasher28 and snowfighter
    The guy i bought it from say that i must remember to reprogram it for lipo, but i think he don't know what he talking about at that point..
    Now i using stock nimh it beep 5 times..
    Should the esc have another color on the led when lipos are connected?

    My stampede vxl lightning green, and red when it programmed to run nimh but the vxl esc dosnt count the batteries with beep so that was a new thing for me to learn

  5. #5
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    I'm using 4s lipo and show yellow/green LED. I'm not 100% but I want to say the ESC has auto detect for cells and also NiMH and lipo mode but again I'm not 100% sorry.

  6. #6
    RC Racer
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    Quote Originally Posted by BuGgYbAsHeR.28 View Post
    I'm using 4s lipo and show yellow/green LED. I'm not 100% but I want to say the ESC has auto detect for cells and also NiMH and lipo mode but again I'm not 100% sorry.
    I understand But you have done nothing other than plugin lipo and then the esc count the batteries?
    Anyone else that are 100% sure that it have auto detect for lipo? Im afraid to run them under 3.0V

  7. #7
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    Ya I've done nothing but plug them in. The default auto cut off for the lipo is set at 3.2v from the factory

  8. #8
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    Ok :-)

    Do you have some tip to buying spareparts?
    Any weak things that will guarantee break soon even if i dont crash it when i use 20 pinion gear on 4s?
    Maby go to the local hobby shop soon, and its a long way to drive so i think its fine to have some spareparts :-)

  9. #9
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    E-Bay. That where i get most of my parts. The hobby shop near me dose not stock much at all and his prices are sky high.

  10. #10
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    I agree, eBay Probably cheaper. I built a whole maxx from eBay haha. Most common to break would be bulkheads and shocks and a-arms. Upgrade to big bores and rpm, rpm makes good stuff for a good price. I would also shim the diff's, I blew the rear twice and now I want to upgrade to 1/8th diff since the truck should be 1/8th. Saving up for the hybrids from flm

  11. #11
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    Ok, yes ibay have better price on the parts.

    Is it enough with one shim? The factory have mount one disc that shim the diff but how many more metal disc should i add?

    Takling about stripping the reardiff, did you done that on 4s and was you carfull that you dont give trottle while landing and dont give 100% trottle on startups?
    I have read that the diffs is weak so i guess i will be prepare on that..
    Going to order gear to have them ready, is it the spider gear that often got strip or that big gear that work as a sealer to the diff with that spider gear that are connected to the center diff/shaft?

    Yes the best is to change it with a 1/8 solid diff, but after reading the 2x3s battery thread it dont looks like its plug and play
    Last edited by Ray87; 05-02-2014 at 01:04 AM.

  12. #12
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    Every diff is different when it comes to shimming. You only shim as much as needed to eliminate all the play but still spin freely.

    As for the stripping, It was the ring gear and pinion that blew the first time and a bearing the second time. I run 2 4s lipos but I built my emaxx from ground up. Flm chasis, rpm everything, steel cvd's, trenchers, big bores, savox servos, aluminum skids. Only thing stock is the diff's.


    I am now saving for the flm hybrids to run 1/8 diff's, I'm heavy on the throttle but those diff's will be bulletproof over stock. I haven't ran a full battery thru it yet and blew the rear diff twice
    Last edited by BuGgYbAsHeR.28; 05-02-2014 at 05:06 AM.

  13. #13
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    Thanks for the advice, i also wonder what the blue sealer on the transmission box is ment for? I know it seals but why should it be a hole there? The long rubber seal 5157 that sit to the left side.

  14. #14
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    Used for the two speed conversion, it allows a servo to mount behind it and manually shift the tranny

  15. #15
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    Aha, thank you for clearing things up. I hear a low dry beep sound when the truck just roll in 1-3mph, when i take it up from the ground and spin them around the sound is gone, but when i roll it on the ground so all the wheels and gears going round then the sound came again one place from the front, any idea where i should lubricate or search for the issue?
    Its very low so i dosnt hear it in higher speeds.. But something is wrong and i must fix it :-)

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