Brushless Help - RC-Monster Forums

johndeerekid · **Brushless Help -** 11.09.2008, 11:15 AM

hey guys im new to the site and i need some BL help. i have a traxxas e-maxx and i just ordered a MM esc and i was wondering if i use a (external)BEC could i run it on 14 cells?? i am planning on running an 8XL motor with it also. -Wes

mikey09120 · 11.09.2008, 12:06 PM

Quote:

Originally Posted by johndeerekid

hey guys im new to the site and i need some BL help. i have a traxxas e-maxx and i just ordered a MM esc and i was wondering if i use a (external)BEC could i run it on 14 cells?? i am planning on running an 8XL motor with it also. -Wes

yes it can but i recommend lipo batteries. what kv is the motor? the voltage limit on the mm? someone else will chime in

rootar · 11.09.2008, 12:24 PM

the 8xl is a 2200 isnt it? and yes using an external bec the mm should run on 14cell you might wanna get a big external cap and a novak 25mm fan to help it out, and like mikey said lipos will make a night and day difference over the 14 cells, youll prollly get a good bit of cogging and stutering under acceleration with the nimh and lipo wont do that.

its a night and day difference just running a mm and 5700 combo in a tiny buggy between nimh and lipo, im sure it will be more noticable in an emaxx.

E-fanatic · 11.09.2008, 11:14 PM

Huge difference from nimh to lipo with the 8xl.
If you would like to run 14 nimh batteries then yes you would need a ubec for it.
Other than that you should be good

You may want to pick up one of mikes motor clamp/heatsink for that motor (it is a nessecity b/c without it the end bells will fall off)

johndeerekid · 11.10.2008, 05:09 PM

okay so it will work. so i just need to get this- http://www.castlecreations.com/products/cc_bec.html orr is there a different one? i am planning on running a feigao 8xl. and i want to go lipo but my nimh will have to do for now. if theres anything else that i NEEED to run this set up please gimme a link to it. -Wes

E-fanatic · 11.10.2008, 05:22 PM

That will do. I have the same one and it come set up at 5volts output. I hooked it up to the castlelink and set it at 6.7volts(to get the most from the radio and servos and thats what a 5 cell reciever pack puts out) The castle link would be a good investment too since you could use it on the mm and the ubec

Dont forget the motor clamp/heatsink IT IS A MUST!!!!!!!!!!!!!!!!!!!!!!!

JThiessen · 11.10.2008, 05:59 PM

Hey, JDkid - welcome to the forum. Nothing like that JD Green!

You will need a couple 5mm bore 32P (aka .8mod) pinion gears. Mike has them in his store, as do most other major RC retailers.

johndeerekid · 11.10.2008, 07:11 PM

okay so CC BEC, the CC USB chord, some pinions(how many teeth??), and one of these?- http://www.rc-monster.com/proddetail.php?prod=RCM01 . -Wes

suicideneil · 11.10.2008, 07:23 PM

8XL +14 cells on a 3906? = 20/66 = 35mph, best you could hope for really.

A little more info might be handy, such as which emaxx this is, any important changes such as 1/8 scale diffs, or which slipper setup you have (stock, RR etc), and what other upgrades you have. A stock 3906 wont hold upto BL power for very long, but a stock 3905 will be fine...

johndeerekid · 11.10.2008, 09:46 PM

okay well i might as well post up my maxx

this is the maxx that its going into, the P-Maxx-

its got all purple RPM, skids, shock towers F/R, arms F/R, bulkhead brace, GH racing rear aluminum bulks, custom aluminum skids, RPM F/R bumpers, RPM Knuckles all around, integy piggy back shocks, Trinity XXtra firm springs, OFNA Mutilator tires/wheels, and i got a JR racing servo on the way, and im running 2 7cell maxamps 4700mah battts. thats the maxx thats this BL set up is going into. i have stock slipper set-up. -Wes

BL_RV0 · 11.11.2008, 12:00 AM

If you have the cash, get a medusa 70mm motor instead of the 8xl. Much more efficient and powerful for not much more $.

suicideneil · 11.11.2008, 01:21 PM

Purple... **shudders**

In which case use a pinion with 1 more tooth than I suggested since this is a 3905, or a spur with 2-3 fewer teeth. Since the MMM can run upto 18 nimh cells, that may be something to think about....

johndeerekid · 11.11.2008, 06:35 PM

what medusa motor would work best?(i dont really wanna spend alot thats why i was thinking the feigao). hey whats wrong with purple:D and yeah i was thinking MMM but i already got the MM, so. -Wes

suicideneil · 11.12.2008, 02:44 PM

Same rules apply when choosing a suitable medusa- they are just like neus, and same size as the feigaos with regards to L can and XL can sizes etc. I would say a 2000kv 60mm medusa was fine for 14 nimh cells, or 4s lipo if you make the leap one day. A 70mm 2000kv version would be even better, but I dont fancy your chances with nimh cells, they will run very hot with a more powerful motor...

BL_RV0 · 11.12.2008, 07:41 PM

They run hot period.