Brushless setup for E-Revo, advice please ?

[Mofomaxx]

Hello, all, been a while since i posted here but the immenent E-Revo arrival has resparked my interest in all things electric & once again im tempted away from nitro.....

So, my question, in a nutshell, and i appreciate with the E-Revo being so new some of this is "best guess" territory, im looking for maximum runtime & an improvement over stock performance, from reading a load on here & elswhere i'm assuming a pair of high capacity 7.4v lipos will drop right in giving me 14.8v (which seems a popular setup in other Gmaxx/Emaxx applications), i'm also assuming i should wait for the MMM to arrive, especially since i'm going to be waiting for the E-Revo anyway, so assuming that lot is correct what are my best motor options for runtime/performance in that order whilst running on 14.8v ?

Hope that all makes sense to someone...... cheers,
Andy

[suicideneil]

Well, concidering the Erevo will use the same tranny, and same diffs (internals) as the emaxx 3905, then your choice of esc and motor should be identical to that which you would choose for the emaxx, which makes life easier. if you go for the MMM esc, it would probably be worth going the whole hog and running 2x 3s lipos, though 2x 2s will be just as good with the correct motor. Size wise, 8000mah 2s lipos will fit, or 5000mah 3s lipos- unsure of the manufacturer, but Im guessing those are maxamps lipos that Traxxas tested with.

That pretty much tells you what size/capacity lipos to run, though there are plenty of other makes and brands, just be aware of the dimensions.

[Mofomaxx]

Cheers for the info, i was hoping that it would be relativly simple to configure given it's similarity in size/weight/layout/etc to emaxx & gorilla chassis e-maxx/revos etc... i'd prefer the2x 2s (that is 14.8v correct ?) 8000mah option as my main concern is runtime, so if we take it (for now atleast) that 2x 2s 8000mah lipos with the MMM are going in there, whats my best motor choice for getting a fast setup out of 14.8v ?

[BrianG]

yes, 2X2s is 14.8v. However, if you go up to 6s, you can get smaller capacity batteries with no loss in runtime. The idea with higher voltage is to reduce current for a given power since high currents is what makes things heat up and run less efficiently.

For a given power, a 5Ah 6s pack will give very very close the same runtime as an 8Ah 4s pack.

[suicideneil]

Motor choice would depend on budget really. But here are a few examples:

Cheap: Feigao/wanderer/nemesis 8xl or 9xl, KB 45, MegaMotor 22/45/1e, Medusa 36/60/2000kv

Not cheap: Neu 1515 1y, lehner 1950/6, Hacker c50 maxx

Mike has a good selection, and ImpaktRC has an even better one (strange but true): CLICKY.

[Mofomaxx]

No budget restrictions apply to this one, though im not into buying a "badge", but if it's noticably better i'll happily pay for it..... Neu is a name that i see croping up often, but there's soooooo many, even in the 1515 range that it confuses my old brain !

Brian, gotcha mate, message received & understood !

[jhautz]

For 4s go for the 1515/1y

for 6s go for the 1515/2.5D

Either way you will smile when you pull the throttle.

And yes... The Neus are worth every penny.

[Mofomaxx]

Anyine fancy explaining in a nutshell the differences between the various 1515 motors ? why the 1y on 4s & 2.5D on 6s ?

[Sammus]

the 1y and 2.5d etc are how many winds the motor is made with, along with the termination (ie how the winds are joined tgether). Basically, more winds = lower kv, higher torque. Y termination = lower kv higher torque than D termination

I think there are so many differences to basically get a lot of kv options with all the different size motors, then you choose the wind with kv to suit the batteries you plan to run. neu's are rated to 60,000rpm, but i think their optimal efficiency is around 50,000rpm so you dont want to have it revving much past that. I'm pretty sure on all that, I dont own one though and am working from memory from research i recently did, im sure someone will chime in and correct me if im wrong :P

[Mofomaxx]

Thanks for that, atleast i have a clue now !! it's begining to make sense, if a little more complex than non brushless 10x2 type configurations, atleast i now undrstand how/why etc.... cheers

So do we know for sure the power handling capabilities of the MMM yet ? im assuming since Traxxas say they've tested the E-Revo on a 6s BL setup, that 2x 3s packs will fit, so that would mean the other option is to run 2 x 3s packs @ 22.2v (?) with the 1515 2.5D, assumimg that's no bother for the MMM and assuming i can squeeze decent capacity 3s lipo's in the E-Revo battery compartment.....

[Trick440]

I have only had 1 brushless motor in my Revo so i don't have much experiance, but.. I have the 1512 2.5d. I went with this motor hoping for longer run times. On 1 True Rc 8000Mah 4s, I have so far went about 30minutes.. and its not dead yet. The spur gear went out and I took her down to the bench to get fixed and do a few more adjustments.. so I do not know how long this battery will last. 30 minutes so far and I'm impressed.

[Sammus]

Trick440 whats your gearing?

[Sammus]

someone measured the trays at RCX and I think they were 165x51x30 or something. biggest batteries on the market that fit at the moment I think are 5000mah 3s enerland cells.

I'm kind of hoping that measurement wasnt totally accurate and that A123 cells will fit side by side in there, maybe if they sit on an angle. Someone did mention the trays werent perfect rectangular prisms so this might be good. I'm hoping traxxas realised A123 were becoming more and more popular and designed the trays to fit them. I guess on the other hand the trays are enclosed so you don't need the bash proof ruggedness of the A123s anyway.

edit: I think in the early stages the castle reps said the 6s monster will be capable of 200A continuous. Someone correct me if that was ever updated.

[Mofomaxx]

5000 mah 3s with the 1515 2.5D & MMM then ? I'm guessing if i get the gearing right & keep the E-Revo lightweight, which is my intention anyway, then from reading the "what's your runtime" thread on here 20+ minutes should be attainable with good performance aswell.....

[Sammus]

Id expect so, I cant really back it up though :)