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Thread: I'm confused?

  1. #1
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    I'm confused?

    I am just playing around with my Daughters new merv this morning and it says in the traxxas manual to install the included high speed gear to run two batterys, and only use this gear for long high speed runs, well I took the motor off and the the 28 is already on there, I put the 23 on and it is clearly a lower speed with better bottom end than the 28, what my question is is why does it say in the manual that the truck comes with the low speed gear installed? what gear should I use to run it with two nimh batts in series and should I change the gear to run it with just one or two in parallel?

    Thanks and sorry if it's a dumb ? I'm a noob and it's just what the manual says does not jive with what I found when I went to change it, a bigger gear should be the high speed gear right

  2. #2
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    I havent personally messed with the brushless but if you run the 28 with series could heat the motor up because it has to work harder. When you double your voltage more or less you double your motor speed. So if you run the 23 with series its faster than the 28 with parallel. Hope this answers the question for you

  3. #3
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    Quote Originally Posted by wannabe4x4 View Post
    I havent personally messed with the brushless but if you run the 28 with series could heat the motor up because it has to work harder. When you double your voltage more or less you double your motor speed. So if you run the 23 with series its faster than the 28 with parallel. Hope this answers the question for you
    Pretty much hit the nail on the head. It'll fry the esc though. I didn't understand this when I got my merv and ran two 3s in parallel with the 28tooth. Crazy fast but too much for the esc.
    addicted much....

  4. #4
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    Thanks guys, good thing I looked at it I guess, like I said it claims in the manual that it comes with the 23 installed but it wasn't, at least with -25 temps outside like today that should help keep things cool, lol

  5. #5
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    Tomorrow will be better!!
    Is her's brushed?
    I plan on buying what I need tomorrow from Hobby World to run two batteries. (Mine's brushed)

  6. #6
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    No it was right the pinion gears are backwards in names. The 28 will go faster than the 23 thats obvious mechanics but if you run the batteries in series with the 28 you risk over heating the esc( thanks finisher i couldnt remember which one heats up quicker) and the motor will run hotter. Temperature out side will help it run cooler but only for the first 4-5 min or so then its on its own unless you stop and let it cool. The 23 is going to be slower than the 28 comparing them in series but comparing the 23 in series to the 28 parallel the 23 is faster and alot better on your merv.

  7. #7
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    Im guessing its brushless cause my brushed didnt come with an extra gear. If it is brushed dont run. The batteries in series

  8. #8
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    Im running (2) 2s lipos on my merv in parallel mostly. Should I change to the 23 and run in series more ? Which will faster
    E-REVO MMM - Stampede 4x4 6s/3s

  9. #9
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    2x2s = 4s = likely death for your ESC. It will be faster if you run them in series but I believe experience has proven that 4s is too much for the stock ESC to handle.

  10. #10
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    If you run lipo's in series on a stock vxl3m it'll fry your esc!! You should only run nimh in series. Reason being your doubling the voltage of the given battery. Hopefully jimmie neutron or 50togo will chime in. Those guys know their stuff!
    addicted much....

  11. #11
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    Quote Originally Posted by Clint Cart View Post
    Tomorrow will be better!!
    Is her's brushed?
    I plan on buying what I need tomorrow from Hobby World to run two batteries. (Mine's brushed)
    It's the Brushless, got it from future shop on sale last week for $255.00!!!

    They also had the brushless ecs/motor's on sale so I bought one for my son's 1/16th grave digger, its basically the same as a summit vxl 4x4 now, and cost me twice as much as the merv, lol.

    Future shop had a parallel connector that you need to run two batts hanging on the shelf for $9.99

    I'm going to hobby world right now the get the motor plate I need to install the vxl in the digger.

  12. #12
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    I fully understand the 4s concept and yeah its nuts to control. But Im wondering if Im better to run the 23 with the (2) 2s in series opposed to the 28 with the lipos in paralelle ?
    E-REVO MMM - Stampede 4x4 6s/3s

  13. #13
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    I don't have any lipo's yet and with a 4 and 6 year old driving I don't plan on it any time soon.

  14. #14
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    Fireman dont run the 2s lipos in series if you have the stock esc if you wanna try for
    More speed try the nimh batteries in series. im not sure what the difference in speed is between the 2. Chkmate you can run the nimh in series but before id turn a 4 or 6 yr old loose with that setup on the 23 tooth id make a test run to see how fast it will go

  15. #15
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    Quote Originally Posted by firemanJBI View Post
    I fully understand the 4s concept and yeah its nuts to control. But Im wondering if Im better to run the 23 with the (2) 2s in series opposed to the 28 with the lipos in paralelle ?
    No question, parallel and 28. Or parallel and 23.

    If you're on the stock ESC, it doesn't matter what pinion you have, 4s (2-2s in series) will wreck it. Its got nothing to do with how hard it is to control, its more voltage than the ESC was designed to handle.

  16. #16
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    I havent messed with the lipos how many volts is a 2s?

  17. #17
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    2s is 8.4 volts. So two in series = 16.8, or too much fur the vxl-3m


    Sent from my DROID BIONIC using Tapatalk 2
    Sl4sh with CC MMP 3800, 2 mervs, a 3905 BL eMaxx,

  18. #18
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    Nevermind i forgot 3.7 v a cell. And the 2s lipo will make it run faster but alot of ppl have been running a different esc cause the stock one goes out pretty quick with the 2s lipo. There are some other threads about changing the esc and running the 2s and 3 s in series on the merv but 3 s was with a different motor as well as esc. The nimh batterries arein series 14.4 volts+/- and the 2s lipo in series is 14.8 volts +/- . But the lipo batteries dont have the same amp draw as the nimh ( correct me if im wrong got this from a couple other post) they stay at a straight ampdraw the entire time with a lil drop when full throttling, while the nimh drops pretty good under the same load as far as amps are concerned. I noticed this first hand with running 1 nimh vs 2 nimh in parallel.

  19. #19
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    2s is 7.2v.
    addicted much....

  20. #20
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    Yeah i had a brain fart lipo = 3.7v a cell s means cell. Nimh is 1.2 a cell with 6 cell = 7.2 , 7 cell= 8.4. Speeking of has anyone ever ran a merv on 8.4 cause i was thinking about it but doesnt look like it has the space in the battery compartment. Im running brushed 550 12 t motor. Everything iv heard said the esc is capable of 9.6 but blows with it ran too much but sustainable 8.4. If someone has ran an 8.4 7 cell in a merv that be awesome to know it fit. I might just make a battery pack for it since i found some 3.6 v nimh batteries

  21. #21
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    Quote Originally Posted by the finisher View Post
    2s is 7.2v.
    7.4 volts on the lipo

  22. #22
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    Quote Originally Posted by wannabe4x4 View Post
    7.4 volts on the lipo
    A 2s lipo is 8.4v when full charged. 4.2v/cell.

    My brother bought a 3s battery yesterday for his girlfriends Merv and it just wants to backflip at half throttle.
    Last edited by Zepher; 01-14-2013 at 02:18 PM.
    ERBE, ERBE, Summit, Slash 4X4, Bandit,

  23. #23
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    Yeah straight off the charger i agree the 2s lipo will most likely read a 8.4v and the 6 cell numh will read 7.5-7.8 off the charger but youll only get that for a short time then its back down closer to the displayed voltage. Also depends on the charger what the voltage will show when you first take it off. Thats nice on the backflip im limited since i got the brushed version it wont even pop a wheelie with the stock gears and 6 cell nimh. Flipped the trans gears to make it slower itll ride one but it goes in cicles cause my wing is bentout of wack

  24. #24
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    Under load it is below 4 volts per cell
    Backflips are a sure way to strip a diff. Shimmed or not!

  25. #25
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    So if it's ran with just one stock battery and training mode what is better for the truck? 23 or 28?

  26. #26
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    One stock battery you can use the 28 all day long. Training mode or not. Its when you run two stock batteries in series or run lipo's that you need the 23.
    addicted much....

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