motor selection... E-Revo

[Mallanaga]

long time no see, fellas. i'm looking to get one of the stock E-Revos... only build it up myself, from choice parts, and stuff.

i'll be using the MMM. just seems right. batteries... i'll stick with maxamps as i think they're the most cost effective. i have options of 2 2x8000 or 2 3x5000. here's my qualm... i want to run 2S 16AH!!!

that being said... can i get away with running a high kV motor, and hope the mAH involved will compensate? i'd be able to keep the RPMs around 40k with a 5500kV neu. if i went with a lower kV motor... maybe something in the 2ks... i'd be looking at 15-20k RPM. is there enough top end there? could i gear up on that and be happy? isn't all the torque in the 50-60k RPM range on neus? i don't know... you tell me.

while we're here, let's compare neu motors. are the castle neu's going to be the same, worse, or better than... neu's neus? i'm rambling. talk to me guys. should i abandon my run time wet dream? lol. talk to me.

[Sammus]

2s is nowhere near enough to a 1/8th truck, and maxamps are the least cost effective batteries :)

running 4s 8000 will get you much better run time than 2s 16Ah, because higher voltage is much more efficient use of the battery power, 6s is even better.

Castle neus will be at least as good as the steve neu's.

[Patrick]

You can't just look at mah for your runtime, you have to look at watt hours.
Watts = amps x voltage
So a 4s 8000 milli amp hour (8 amp hours) battery will be 14.8v x 8 amp hours = 118.4 watt hours.
A 2s 16 000 mah battery will be 7.4v x 16A = 118.4 watt hours.
No matter which way you wire those cells up they still have the same total amount of energy, so the 4s 8000 mah setup will be better, because you need half the amps to make the same power (watts). Too many amps puts more stress on things and any resistance through wires etc. becomes more noticeable.

Personally I think for a neu 1515 30-40k rpm is enough for normal use.

[jhautz]

2s in a big truck like that will just cause you problems. Run the packs in 4s 8000mah config and choose a properly suited motor for 4s. You will be much happier in the end.

[suicideneil]

Last time I checked this was RC-Monster, not the traxxas forums; anyone who doesnt see my point should probably stay on the traxxas forums...

[BL_RV0]

Well said.

[Mallanaga]

thanks for the help guys... or not. i'm not a complete noob at this, but considering i haven't been into RC in about a year, i'm a little rusty. as for brushless / lipo business goes, i have a lot to learn, but i'm more than willing.

like i said... i plan on building this myself, from choice parts. keep in mind, there's no kit available. only problem is... i know my old revo inside and out. hopefully all the new parts on this electric version don't throw me off - they shouldn't though.

so i don't want to put a G3R in it... sue me. i might throw some of mike's sweet diff's in there though ;). it'll still be a monster, but i just want something reliable, cheap enough to fix things, and long ass run times.

now about batteries... i guess i can take this to your revo section. i'll just throw it out there. i'm all about getting what you pay for. that in mind, i want to pay more money and get some sweet batteries, but none of them seem like they'll fit in the stock E-revo chassis. i've spent years in RC modifying and customizing my RCs... i'm done with that. i've checked thunder power, apogee, and tanic, and none of them had batteries that seemed to fit the E-revo. MA has a few listed, pretty much made for the damn thing. i guess i have to look harder, or wait for something better to become available.

with my new found knowledge... i'll go searching some more for the ideal combo of motor / battery. thanks for the heads up, guys... all of you ;)

cheers

oh... PS, i'm reading that FAQ in your sig, neil. thanks. :)

[jhautz]

http://home.comcast.net/~truerc/read...eady_packs.htm

The 8000mah packs here are just as good as the maxamps in my experience and they are way cheaper. a pair of 2s 8000mah wired in series for 4s 8000mah should be a very nice setup in the e-revo for long runtimes. Dont let the numbers throw you. These packs perform better than the specs and the maxamps dont perform as well as they are rated. Just my 2 cents.

[Sammus]

Most enerland based 3s 5000 packs fit. Pick up a couple of the polyquest versions for $118 each from hobbycity and you can't go wrong. Cheaper than MA and a million times better.

[suicideneil]

Lol, dont take it personally; Im dishing out tough love to anyone new lately (traxxas forum does that to a guy's brain...).