just got a new 3905 E-maxx.

i had it for 2 hours and i'm planning mod i want to do to it.

i will post some pictures later.(going out driving soon.)

first off has anyone use the A123 dewalt battery's in a stock e-maxx, what was your setup?

what i would like to do is put two 3-cell A123 (yes i know 10.8v) in parallel, but i need to find or make a voltage regulator that can do 8.4 max with 30A capability.

or do the other option is three 2-cell 7.4 in parallel. so is there a better way or i'm i just crazy thinking about this?



i'm not the best at soldering or electrics but i'm a geek and willing to try new stuff.

here some pictures. it was a blast to drive today.(for a electric rc it was surprisingly fun.)

[suicideneil]

Geek, and crazy. What do you need the voltage regulator for exactly?

If you want to use A123s, then the best option for a stock emaxx is 5s, so a 3s and 3s pack in series; only when you start playing with BL setups do you need a pair of 5 or 6s packs in parallel (6s2p for example like yours truelly runs).

The 10.8v itsnt going to net you more than a snails pace top speed, unless thats what you want, and 7s3p of nimh cells is just daft- thats about 3lb of batts, one pack of which has nowhere to mount to (easily atleast).

You dont need to go crazy with weird electrical setups, follow conventional wisdom to avoid burnt fingers and electronics

What are your future intentions for this truck anyway?

^guilty as charged. well correct me if i'm wrong but each A123 (or LiFe) cell has 3.6 (max possible but i doubt there truly at that voltage.) and my stock maxx can take 8.4v per a line.

so 2C A123 is 7.2v, 3C 10.8v i would like to run 6C A123 on each line, from what i under stand i can do 3 2C in parallel or 2 3C in parallel with a 10.8v-to-8.4 with 30amp VRM, i can use a resistor but they waste the extra power making it worthless to use.


i think it might be worth just to get some LiPo batteries instead it's easier.(cheaper )

what do you think of the zippys and Kershaw Designs LiPo's?


as for mods all the standered mods for a T/E maxx.(listed below and in order of upgrade.)

-RPM all around.
-FLM/GA/other AL bulks(undecided)
-lunsford racing Turnbuckle Hinge Pin Kit with Tony's Screws kit
-two hitec servo HS-6975HB (i think i have the model # right.)
-LiPo Batteries
-traxxas CVD.(not the centers.)
-FLM #3905 V.2 chassis
-Muggy/LST1/2 Diff mod.
-spectrum DX3.0
-proline wing with tekno wing mount, and RPM black 17mm Revolver rims with whatever tire i want to try.
-Proline Powerstroke or UE shocks or Traxxas big bores.
-Revolver 700-HO motors.(owning to that this is the last on the list, i may get a BL instead.)

it's good start for now.

[suicideneil]

Using a voltage regulator is a first for me, but it seems like a bad idea for a few reason, not least because even brushed motors can pull peak currents way in excess of 100amps under the right (or wrong...) circumstances- that would blow the regulators to bits. Best option would indeed be lipos; for as much as I love the A123s, they are a pain sometimes due to size/weight/ funky voltage. Zippies are best value for money by far, even if the QC isnt as good as it should be (thats what the lincpimp is for )- havent looked at kershaws lipos, so cant comment (if it says maxamps on the label avoid it like the plague though). SPC and trueRc lipos are very good too, as are Mike's own brand items in the rc-monster store- depends how much you want to spend really (I have a list on my website of good places- http://robotwars.00server.com and its on the truckslinks page if you scroll down to the battery section).

Your list of hop-ups looks pretty good- probably better to go with BL really, even if its a milder hvmaxx system- replacing brushed motors every 30-50 runs gets rather old rather quickly, even with the beefier Kershaw drill motors.

i'm amazed how cheap everything has gotten over the last year and halve. BL system and lipo used to be so pricey now there dirt cheap.

if thing go as planned i could get the CC Mamba Monster V3 with the Feigao 580L or the Revolver XL.(it's from the EZRUN combo) or i could save some money and get the EZRun 80/150 combo.

i'm still surprised how cheap stuff is i need to look around some more and see what other choices i have.


the zippy's are $30 with 20c with 30c burst, the KD are $60 with 25c with 45c burst, i'm going after the zippy's i can get two for the price of one and i'm sure i will be happier with them, then the crap venom 3600.




"Is it just me, or is that cockroach shuffling too loudly?"
"Kryten, it's called a hangover. Don't panic."
"On a mining ship, 3 million years into deep space, can someone explain to me where the smeg I got this traffic cone?"


"He's defective. He wants everyone to eat toast all of the time. And if you don't want to eat something like 400 rounds of toast every HOUR, he throws a major wobbler. That's what caused the accident in the first place. "
"What accident? "
"The accident involving me, the toaster, the waste disposal and a 14 pound lump-hammer. "

extra points if you tell me what the toaster say's after the "The accident involving me, the toaster, the waste disposal and a 14 pound lump-hammer. "

[suicideneil]

"Howdy doodley-doo!" ( I cheated: http://www.youtube.com/watch?v=LRq_SAuQDec )

Im pissed as I cant get Dave on digital freeview, so I missed the new episodes- hopefully they'll be a dvd or repeats etc.

I would skip the feigao 580L- metalman had one and it fried on the first run. The hobbycity ones are cheaper, and may be alright, but for $100 the castle motors are awesome, - the MMM and 2200kv motor combo is excellent value, and Castle's customer service is second to none.

Originally Posted by suicideneil

"Howdy doodley-doo!" ( I cheated: http://www.youtube.com/watch?v=LRq_SAuQDec )
yeah that was the hole point, it was worth seeing right?

Im pissed as I cant get Dave on digital freeview, so I missed the new episodes- hopefully they'll be a dvd or repeats etc.
same here, it was/is a great show.

I would skip the feigao 580L- metalman had one and it fried on the first run. The hobbycity ones are cheaper, and may be alright, but for $100 the castle motors are awesome, - the MMM and 2200kv motor combo is excellent value, and Castle's customer service is second to none.
that is good to know, i didn't think the CC motor could be used on the e-maxx(i guess it show how long i have bin out of the electric rc world.)

i wish they would put red dwarf back on the tube.

[C-5Quad]

Im far from an expert but I can tell you that I started the same way you are.....

first was my stock 3906 maxx new out of the box with 6cell stick packs

then I got EG4600 7 cell nimh packs and was super excited about the performance compaired to 14.4v

then went 2 700ho kit from kershaw....even more power but rough on the esc it killed 2 of them

then I got the new 3905 and did the V-twin brushless with 2 VXL systems for a while on a pair of true rc 6400 2s2p lipos......the truck was sick..heres a video of it on 2s

http://www.youtube.com/watch?v=QoEOFP6ukNY

Now I run the MMM 2200 combo on 6s using 2 5000 3s1p 25c zippy lipos and can say it gets down and temps are much better......

In my opinion save for the brushless and lipos first then upgrade what breaks....The 3905 has much better trannys and diffs then the old max and can take a beating......so far my drivetrain hasn't given me a single problem and the only parts on my truck that broke were due to my bad driving......"not saying you wont break anything" but I figure I would share my journy with you and maybe save you some time an money......

I wish I got to where I am now sooner

[mkrusedc]

Looks good the only thing I have to offer if you are not good at soldering is to use Anderson Powerpoles. No soldering required.

If you are in the UK:

http://www.torberry.co.uk/