My Brushless E-Maxx project!
 

hi everybody, i give you my brushless emaxx project, i will be running 6s2p a123's and a MMM, i still need to decide on a motor however, i have narrowed it down to either a feigao 8xl or a kb45 8xl. i like the looks of the kb45 better but i am worried about the size, will it fit in the stock e-maxx motor plate? and is kershaw designs the only place i can find 6mm bore pinions? anyway, i will leave you with some pics of the progress:

chassis stripped of electronics
http://i93.photobucket.com/albums/l5...ssbuild001.jpg

chassis removed
http://i93.photobucket.com/albums/l5...ssbuild003.jpg

new flm goodies
http://i93.photobucket.com/albums/l5...chassis002.jpg

flm chassis installed
http://i93.photobucket.com/albums/l5...assis006-1.jpg

upgraded to 3.3 spec in the front
http://i93.photobucket.com/albums/l5...upgrade001.jpg

as she sits now
http://i93.photobucket.com/albums/l5...upgrade005.jpg

A123's mocked up
http://i93.photobucket.com/albums/l5...3mockup004.jpg

http://i93.photobucket.com/albums/l5...3mockup002.jpg

very nice!
i say go with the 8xl or mabye and out runner and forget about the whole tranny direct drive from the motor to the diffs

Wow, well done, very nice

looking good.... 8XL run fine on my EMAXX but it was on 5S2P A123 (13lbs truck)...I would suggest a 9XL motor with proper gearing would be great plus you get good runtime...but hey this is your truck :lol:

I think i'm gonna go with the 8xl, what gearing would be best for my setup, i ask because pinions are $12 and i dont want to have to buy them more than once:lol:

Nice setup emaxxracer15. I think you should buy a range of pinions as you may find 6s is a little faster than you like with the Feigao 8XL. Using 5S I get plenty of pace, and by changing pinions you can get higher speed or higher torque (I still get wheelies on 5S with the larger pinions but the main reason to use the smaller one is it seems to protect the motor and ESC from temps, so tougher on the geartrain but gentler on the motor). Mind you the torque on my truck is enough to break the standard outdrives- since you have the 3.3s I wonder what will break on yours???!!!!! Have fun. My advice- start with 16turn pinion.

i would rather go a little harder on the upgraded drivetrain than be hard on the motor, so i think i will start with a 16T

Looks real nice. Any future plans in upgrading the tranny?

I will eventually get the 3905 tranny and adapter piece so i can run it on this chassis, because my hack job at locking this tranny into second gear probbably won't hold for long :lol:

Nice truck... I had one of those a few months ago and ran it on 2 Velineon and VXL ecs on 6s. ran great..


http://i264.photobucket.com/albums/i...7/IMG_2144.jpg

best of luck and if you need a 3905 trans mount for the FLM just PM metalman and he can fab you up one..

i just got my monster yesterday and have a quick question about it. do i need an external BEC if i am going to run 6s2p A123's?

Nope, the Mamba Monster comes with an internal BEC. :wink:

ok thanks, that saved me $20 that i had set aside for that.

hey guys, havent posted here in a while but i made some progress on my emaxx and it has came time to buy the final bits and pieces and i ask you this, do i need to use 6mm bullets between the 8xl and MMM or can i use 4mm? i know its kind of a noobish question but i figured its better to ask, thanks!

5.5mm bullets are fine, and easy to come by compared to larger ones (that also cost alot more).

ok thanks neil

ok so i have made some progress with my build, i have the motor and the MMM. and the final bits and peices are in the mail. however, i ask you this, will using an external BEC increase the chances of my MMM not burning up? ive read that the problems with the v2 can be traced to the BEC circuitry. i will leave you with some pics of the progress,

http://i93.photobucket.com/albums/l5...p282008005.jpg

http://i93.photobucket.com/albums/l5...p282008001.jpg

http://i93.photobucket.com/albums/l5...p282008002.jpg

http://i93.photobucket.com/albums/l5...p282008003.jpg

this is a close fit, will this be dangerous for my batts to be so close to the hot motor?

http://i93.photobucket.com/albums/l5...p282008004.jpg

Your batts will be fine so long as they arent actually touching (air is a poor conductor of heat).
Using an external BEC will take some load off of the esc with regards to powering the Rx and servos, but without knowing exactly what causes some MMM becs to die exactly, at best it wont make a blind bit of difference really; if the esc is going to die, theres nowt you can do to stop it, apart from from very tricky internal pcb modifications...

hopefullly your motor will not be too hot because then something may be wrong in your setup.

ya, i think ill just keep the external BEC to unload a bit from the MMM.

Hi, you flipped your tranny right, did you have to get different shafts? Or could you use the ones that came with your FLM chassis. Is it better to have it flipped?

Now that i look at it, i seem to have flipped the tranny:oops: i dont think it will even work right with it flipped. but if you were wondering, the driveshafts that came with the FLM chassis work with the tranny regardless of the direction it is going.

as my last parts arrive i am in need of assistance in locating a suitable copper braid for connecting the a123 cells together in my batt packs. does anyone know where to get some?

Nice build looks alot like mine. I was going to flip the tranny but just moved the batts instead for better weight distribution.

I have two suggestion...tires...radio...

Just search ebay for 'copper braid', plenty of results pop up that way. You will be needing a fairly good iron though, at least 40-50watts or more to make quick, solid joints, without heating up the cells too much.

I just used copper braid made as solder wick. It is sold in places like Radio Shack. Seems to work well for me- love those A123s!

That is exactly what I had in mind for upgrades prior to completion of the build. i am thinking about going with the mx-3 FHSS is anyone using this radio? and do you guys know where i can get some cheap 10 AWG wire? i am talking about the super flexable kind like the wire that comes with the MMM leads. i tried Home depot bu all they have is the really stiff copper stuff.

You can get some nice flexible stuff from ebay, just look for silicon wire usually- airplane and heli sites should have it too.

i decided to just go with the wire from the depot, it was cheap (less than $1 per foot) ant it isn't that bad. so i built the first battery and it was looking all good until i plugged the balance tap in to the charger and i got a ton of beeps saying the balance voltage was too high. i have ordered the usb kit that will let me update the firmware and hopefully solve the problem until then i will just have to wait.

Did you check the voltage with a multimeter? Also, if you are worried about heat between the motor and cells, try off setting the cells a bit. Instead of gluing them in the center, glue them right over top of the outside set of cells. As for the Depot wires, check the temps at the wires for the first few runs to make sure they are conducting right. A good, high quality sub-woofer wire can be found at most speaker shops and work great.

well more bad news, I went to plug the battery that i built in to the MMM and sparks came from the connectors whe i tried to plug the batt in:grrrrrr: so now i am starting to get a bit frusturated. I dont know how to proceed because i can't balace the pack and i can't hook the thing up to the MMM without killing something.

That is normal just the capacitor charging very quickly

As if it hasn't been said enough....It will run very hot, its a Feigao 8xl, even on a good day they're on the verge of meltdown. Generally an 8xl is a 4s motor and runs hot on that, on 6s a123 I can only imagine how hot it will get, I don't give it long till you get a better motor. At the Very least spend the little extra and get a Medusa.

The stiff wire you got from Home Depot osn't going to be good. All the movement when your running it will wind up braking your solder joints since the wires can't move. As far as wire is concerned, if your trying to get it locally and cheap, go to Walmart. Get a car stereo amp wiring kit, or just get 12gauge speaker wire. With the amp kits you can even get bigger wire if you want, just remember that they don't come with much black wire so you may wind up using red for + and -, in which case make sure to label them!

Sparks are usually normal, can be a bit of a shock (pun!) the first few times, it happens, but it just becomes part of a routine, then you get worried when it doesn't spark!

My 8XL ran very hot with a 4S a123 setup, but I have a very heavy truck, and tall (i think thats the word, 20/51) gearing. Have since upgraded to a NEU 1515/1y and it runs cool with the same setup. Worth the money, just start saving your pennies hopefully you will have enough when your 8xl dies.

I am hoping this 8xl will last at least until the CC neus come out. then i can get one of those but if it dies before then i will probbably go with a medusa.

ok well, now i am thuroughly mad because i got the usb hookup kit ($20) and i come to find out that the firmware upgrade is only for eos0606i NET or DUO chargers. I am using the EOS0606i AC/DC charger. so now i have nothing to go on. i have a black balance wire soldered to each of the positive ends (the ends with bumps) and the red wire soldered to the negative end of the pack (where the negative wire goes to the plug) everything should be set up perfectly and when i plug the battery in it still says balance voltage too high :diablo: maybe I should just scrap the idea of even having balance taps in the first place. it sure would make my life alot easier :lol: anyways, the screen shows that the balace voltage should be 3.34v but it is reading my pack to be 4.96v. i don't know what to make of this and i don't have access to all of the tools or the budget to just dump money into these packs until they work(I am only 14) so I thank those who have taken the time to read about my struggles with a seemingly simple task and I will close with this; go easy on me as i am new, but remember that i am not as dumb as you may think:intello:

A123 cells don't need to be balanced. I would just run them in the truck un til dead, then charge them without any balance taps.

then i am screwing the balance taps, building the second pack and running the stinkin truck:yipi: Expect a video soon.

I don't balance my lifepo4 packs. Just wire them up, check that the connections are correct and run it till you lose power, go back recharge and go again! 2 sets of batteries and a high power charger can mean limitless running, as long as the other components are up to the task. Motor, esc etc.

cant you still look at cool important looking data on your computer?...

no but really...i wanna know cuz i want cool important looking data on my computer:lol:...then print it out:rules:...making me cool and important looking