BL Revo or BL E-Maxx?
 

Hi all

I'm new here, and I have a question for you.

I am tired of nitro, so I want to go brushless.
I have a Revo and a E-maxx. But I can't decide which truck to "convert". I like the Revo suspension and the way it "feels" when bashing, but i think it's easier to go brushless with the E-Maxx, since of course its already electric. Also the Revo is a little heavier, right? I read in here that people use E-maxx trannys in Revos, that involves a bit of engineering skills, right? (which I don't have):024: ...

So which truck should I use?
I never race, I want the speed of nitro, and I want more rutime than I have with my stock E-Maxx running NiMH 3000s (after 2-3 minutes the truck starts to slow down:025: ). I read thar Lipos keeps the voltage (=speed?) until they die, that sounds good. What esc/motor shold I use? I'm thinking about the MMM, if it ever gets out...

A lot of questions from a complete rookie. Help me out guys. Sorry for the spelling, I'm from out of town...

Well, its easier to run BL in a maxx, as you don't have to "convert" it, make batt trays, etc, but the Revo is much better suited to handling the BL power. The maxx needs signifigant investment in driveline upgrades, while a stock Revo is pretty much good to go. If you get the RCM motor mount for Revo, its really easy to convert. You just need to make some batt trays and lock tranny in 2nd (to get motor brakes and reverse.)

Those batts are junk. If you get decent lipo packs, it will be a world of differnce better. i usually bashed ~45min-1hr on my 4S 6400 packs, with no real loss of power.

Yes, a maxx truck can be had for a very decent price if you buy the right parts, and put the money where it needs to be. The differentials, and tranny is where the money needs to go first.

Then you most likely have a good radio I take it?

An entry level BL setup (but no slouch!) is a Mamba Max, paired with a 8 or 9XL Feigao.

For batteries, LiPo's are a good choice, but you MUST have careful attention not to abuse them, over-charge, over-discharge, stay within specified voltage limits, even then they can burst into flames for no reason (this is important). LiPo's have great power (decent pack), and have pretty consistent power throughout run, and looong runtimes.

The other choice for batts is A123 Lithium (Lithium Nano-Phosphate), they are a brand new chemistry stirred up by A123 Systems. Main aspects:
-Safe, intrinsically safe (peace of mind)
-super fast recharge of 15 mins, although 5 min charges are possible as well
-lot's of power, ~equal to equivalent mAh rating as lipo, but they can handle currents much better than lipo, again safe.
-Very consistent power throughout run, 100% power right up to a few seconds when they dump, it's very sudden loss of power.
-tough, the cells are made into alum. shells and can take physical abuse. Tough as nails as far as running them, you can over charge, over discharge, etc, with very minor performance impact (unnoticeable)
-Cheap, being half the cost of equivalent LiPo (capacity), as well as having many times the cycle life of lipo, expect at least 1000+ cycles (100%DOD), I have seen roughly 200 cycles come from lipo, that is, if they don't blow up before then...

I'm not trying to bash at lipo here, I'm just giving you a good comparison.

The "easiest" conversion IMO is to get a Gmaxx G3R chassis for your revo. Its bolt on and lets you run an emaxx tranny with steel lidlers, no other mods needed. Downside is its almost $300.

The cheapest is to custom make some battery mounts and motor mounts for your stock chassis revo and run the stock revo tranny. But this does take some engineering/custom work skills.

The simplest bolt on brushless setup would be the emaxx, but like was metioned above. you will spend a significant amount of money trying to get th drivetrain strong enough to handel the brushless power.

I personally prefer the revo. but others will argue the maxx. Properly set up it can be one mean machine. But it takes picking the right parts and in the end winds up just as expensive (if not more) than the revo.

I highly encourage you to do this. Once you do no nitro will ever due again. A Mamba Maxx and an 8xl on 4s lipo will make you smile for sure!:027:

BTW: Welcome to the forum.

Another option is to just sell your revo and watch ebay for a decent revo that is already converted. They pop up more often than you would think. This would probably be the cheapest route if you dont want to do the work yourself.

I personally prefer the Revo even though it does need modifications. Some of it is just the challenge (albeit relatively minor), and some because I liked the suspension setup.

Go with Revo if for racing, Emaxx for bashing but more expensive to convert, if performance is a priority go with Revo.You can't go wrong with either truck.I have them both they are all great.

E-revo, simply because its a better truck performance & durability wise. To fit an E-maxx tranny is no harder than drilling a couple holes and filling a little clearance for the centre drive shafts. Fitting the battery trays is simple too- a hacksaw, ruler, and dremel is all that is required really. And a little patience (measure twice, cut/drill once).

Thanks alot! This is really good info. I've had computer problems, so I couldn't reply sooner, sorry...

Finnster you got up to an hour runtime? that sound perfect!!! But what about power compared to nitro? (I have the trx 3.3 engine). Less top speed but better torque?

Zeropointbug, do I need a better radio? all I have is the TQ that came with the trucks. Yeah I've read about those A123 batteries. They sound good, but why does most people use Lipo's then? Sure I don't wan't to have 200$ of batteries blow up on me... When I bought the E-Maxx I picked up 12 3000 mah (that was expensive, with international shipping and taxes) They are now paperweights because I didn't treat them very good...

I was leaning towards the Revo too, because I love the truck. So thank you guys for confirming that. I don't need the E-maxx tranny if I lock the stock one in 2nd gear? Is the E-maxx tranny stronger?

Is there any rumors about that Mamba Monster Max combo I've read about?

Hi Buggi; let me be the first to publicly welcome you to the forum! (guys! :) )

The mmm might take a while before it's launched. Don't hold your breath, and a 4S setup is all you need to be as fast as the current 3.3 engine. acceleration will be better, torque will increase as well. The revo transmission is proven tough (this surprised me to be honest) it seems to hold up fine for the users here. Locked in 2nd is the way to go, you can keep the 2speed transmission and use the mechanical brake as well. Finnster is using a centerdiff in his revo, this is easier on the drivetrain than a solid centershaft.

Lipo big advantage is that the energy per gram is better. A123's are rather heavy and have a large voltage drop compared to good lipo's.

Thanks Serum!
I suppose I could try the MM, and updrade when the MMM comes out.

I'm confused. a123, a123 Lithium Nano-Phosphate, and a123 Lithium Ion is the same? Or is this Nano-Phosphate something so new, it can't be purchased yet?

Yeah, they are available for quite a while, these A123 cells are basically the same. A friend of mine who emigrated to China to develop handheld powertools told me they need to wait for 2 months before the A123 cells are available again. You can buy a Dewalt 36V pack and build a 5S2P pack from the cells. these packs retail for about 120 bucks in the US, in europe they are about twice as expensive.

Okay. I'll consider that. Or lipo. At Maxamp.com the best a123 cell is only 2300 mah. Thats not much compared to 10000 mah lipo cells. I'm looking for long runtimes. The E-maxx on NiMh was driving me insane.

By the way, where do you pro guys buy batteries?

I guess you are using poor cells on your maxx; normal NIMH packs also have got about 100 percent performance 10 seconds before they run empty.

If one cell in the pack is bad, (empty sooner than the others) it will lead to problems though.

You can get the maxamps packs from rc-monster.com. Mike also carries the flightpower packs.

The power is fantastic, I have yet to see a nitro that would worry me. I'm not a huge nitro nut, and I am far from seeing them all, but I've seen a number and not one would I be jealous of. At the LHS, I ran it a bit with a guy w/ a truggy w/ a .27 Sirio, and another w/ a ~.28 or so Ofna buggy. My REvo was way faster than the truggy, and very much on par w/ the buggy. Maybe a bit faster accel, but not quite as much top end (at least on 4S lipos).

Click the links in my sig for some vids that shows off both 4S and 5S.

4s is a great setup unless you are a speed freak. Anything faster can only be driven on streets IMO. I have a 5S batt and it murders, but too fast for most things. What you really want it Tq and Accel, and BL had loads of it. Don't get to wrapped up in top speeds unless you just run your truck straight up and down the street.

TrueRC Lipos are also good for a very reasonable price. Not the C rating of Maxamps of FPs, but certainly good enough for bashing. If the lipos are rated for at least 100A continuous or so, you are good. The runtimes I get are bashing around. If you just drive up and down the road @ WOT then maybe 20-25min for 6400. and 30min+ for a 8000 mah batt. A123s are good if you are not the most careful person w/ your batts. I may get some of these next. A 5S2P 4600 mah pack would be great. Little more power than 4S lipo, little less runtime, but everyone I've seen its still really good. They are cheap enough you just get two packs then. :)

Ehem...

Great work Jhautz..

smallest font you could find, at the end of the post.. :p

:005:


I aim to please.

Finnster is right, 4s lipo is mostly good enough power for brushless, I have a 6 s 8000 mah lipo from maxx amps on my emaxx and it can go 50+ mph on a LARGE ASPHALT PARKING AREA only.It was fun at first but it gets old quickly .Too much top speed on a grass or soil with slight one mistake will cost you $$$$ to repair.

I want the MMM 12s Lipo!

Okay. Revo it is. The mamba max esc is only good up to 3s lipo. But people run 4s, right? What motor should I get? The mamba's are too small, right?

Yeah, an XL would do a better job. the mamba motors are not intended to be used in these larger vehicles, unless you gear it tall or use two of them (but 1 single XL setup will be cheaper and more efficient)

Just to clarify, by XL you mean Feigao/Nemesis/Wanderer "XL" Brushless Motor right. But XL is also the size of the motor, right? And will I have any problems running 4s with mamba esc? I know I ask alot of questions, but this is new to me. :002:

Could I run a Lehner? Is that worth 300$? I've sure read some great reviews of those.:043:

Yeah, with XL i mean the XL of wanderer/nemesis/feigao, in 540 size.

The advantage of the lehner motors is that they use segmented magnets, which makes them more ideal for partial load. (about 95% of the time it's used, it's used on partial load) and the lehners are topnotch. They don't require an optional clamp the keep the front/end bell on.

4S would be no problem for the mambamax, you need to use an external UBEC though, and disable the internal BEC by disconnecting the red wire that goes from the controller to the receiver.

But do you get THAT much more power/runtime? I mean, they are pricey...
Okay I'm a rookie. UBEC, Universal Battery Eliminator Circiet (how do spell that?) what exatly is that?:007:

The receiver/servo's/speedo need power to work on; they normally work on 5-6V, since the batteries are usually higher in voltage, it needs to be transformed into 5 or 6V. Normally a BEC (Battery Eliminating Circuit) takes care of that, but since the normal BEC's use a circuit which works rather inefficient, (with a simple transistor) and are rated for a rather low voltage you need a special switching BEC that takes care of that. You could also use an external receiver pack, next to the batteries you use for powering the motor. This adds weight and it needs to be charged too.

Okay. Thank you for your help, Serum!

No problem Buggi, it's quite confusing with all the new names to keep things apart.

I'm also trying to BL my Revo can someone help me with a pinion gear? What size would you recommend using I was planning to run 5s lipos with a 12L Feigao. But not sure what pinion to go with.

Check out Brian G's Speed calculator.. it's awesome!!
Hook'em up with the link Brian... :D

http://www.scriptasylum.com/rc_speed/_top_speed.html

Plumb all the things you know into the calculator- motor, voltage, diff ratio etc, then experiment with the spur/pinion ratios until you hit the magic 40mph mark I reckon. Bear in mind the maxx speed you want to run the motor at is 40,000 rpm or there abouts.

Where can I find Brian's calculator?

In the post right above yours. : )

Or, the R/C Calculations link in my sig. Or, the sticky in the brushless section.

Or in my favorites, right under the link to the RCM store!!!!

lol, I don't think he can access your favorites.

Is it just me, or does that sound like a bit of innuendo?.....

gross.