I have just completed building the E maxx of my dreams. I'm still in the process of upgrading the remaining plastic parts to aluminum, but I have most of the go fast goodies in place.
I started out with a Dynamite chassis that will hold 4 battery packs. I felt the need for this since Dual Hv Maxx motors would be supplying the power. Dual Escs with motors spinning upwards of 70,000 rpms is enough to present the challenge of getting all this power to the ground without breaking parts.
For gearing, I'm using the 21 tooth pinions and a 64 tooth spur with all 12 friction pegs installed. Then I cranked her down to allow only minimal slippage at the clutch.
All of this grants an estimated top speed of around 60 mph. But I have to work the bugs out first.
Tire Balance and Swelling. It's amazing how these soft tires react to being spun this fast. I need a way to balance tires, and maybe look toward some harder compound that doesn't swell so much. These soft ones totally distort!
Bullet Proof Differentials! Second time out, I sheared the Ring screws. I haven't even tore it back down yet. I heard them snap with a loud Pop! Then all the sudden, I had a front wheel drive E maxx that would smoke the tires on concrete! LOL
I have the Purple aluminum diff cases. I have just ordered the aluminum diff cup, hard gears, and the 3 mm screw setup to rebuild this diff with.
Putting this much torque to the ground is really going to punish the diffs.
Can you guys give me some good cost effective advice on how to build diffs that will hold up?

This thing accelerates like crazy! I did manage a few second gear high speed runs before the diff broke. It's going to top out over 50mph. I need to come up with a way to verify that. I wouldn't mind putting this thing up against a tricked out T maxx. A stock T maxx wouldn't stand a chance! hehehhee

Take a look at these pics! Let me know what you guys think!

Very nice! Too bad for the grand total of money spent on it.

Sean

how much did u spend on that thing?
can we get some video or somthing of its power?
that thing must wheelie on command

I'll try to get you some video as soon as I get the diffs rebuilt. I'm also waiting on some Purple Dust boots for the cvds.

I've been thinking about good video ideas. I need to get with a cop and ask him "Man will you clock this thing when it comes flying by?" LOL

Maybe a person standing behind him taping the speed gun results!

I'm thinking around 60 mph. I know it gets outta site in just a few seconds.

Maybe if I can get the diffs worked out. show a smokey burnout on concrete. I know it has the power to do it.

I'm wondering if going with the Ofna wheel adapters and the 1/8 buggy wheels might be a good answer to the tire swelling. Anyone have any experience with those?

but some duct tape on the inside of your tyers and it hlps stiff them up , do it going with the tyr and give it a coupple of layers

Ok I got it all back together and running. Charged it back up, took it out for it's third run and stripped out the transmission!!!

Talk about being over powered! Every weak spot is giving up to all this torque.

Looks like I'm going to have to bullet proof the transmission also. Anyone have any good suggestions on that? I know I'm going to have to replace these weak plastic ones with all metal ones.

OMG taht is like giving a 90yr ols man a double dose of viagra and a Playmate!!!!

Is that thing stock except for the brushless?????

There are still a few stock parts left. LOL

It's a work in progress. Here's the list of parts I have for it so far.

Aluminum Quad Battery Chassis
Aluminum Chassis Braces
Aluminum Bulkheads
Aluminum Diffs/Rear has hard gears with aluminum diff cup
Aluminum Bumpers
Aluminum Shock Towers
Cvd's on all 4 corners plus cvd centers
Dual cooling fans powered off a 7.2 volt Lithium Ion Battery pack - this also powers the radio and the servos
Purple RPM A-arms - not installed yet
Purple cvd boots - not installed yet
64 tooth spur with all 12 friction pegs installed/21 tooth pinions

Dual Brushless ESC's/Hv Maxx Motors

Currently running 4-3300 mah packs - I plan on adding for more cells to bump the voltage to each ESC from 14.4 to 16.8 This will yield a significant speed/power increase. However, I see no reason to do this yet as I'm not yet able to put this much power to the ground without breaking parts. LOL

In an earlier post, I had said that I thought it has snapped the ring screws in the rear diff. That's not what happened. I still had the plastic drive shafts on all 4 corners at the time. It snapped one of those! LOL

Hey
Awesome E-Maxx!! I have never seen a dual HV-MAXX E-maxx. Totally tricked out. Any success with the continual strengthening of the drivetrain?
Nice work though!
Are you running a receiver pack? Is that what I see on the front of your truck?

Thanks!

I'm still looking for metal transmission gears and an aluminum transmission case. It appears the factory drive dog can't withstand the amount of torque I'm trying to force through it. If I don't find something soon, I'm thinking about taking a brand new plastic one to the machine shop and see if they can't duplicate it for me.
The factory transmission is pretty torque and heat intolerant if you try to put too much through it.
I've been doing my research though. On the Ofna Dominator trucks, they have a bullet proof factory setup that can take the abuse.
It is a single speed slipper spur setup. It doesn't have any gears in it other than the spur. The center drive shafts come right off the ends of the spur axle.
A setup like this wouldn't be a problem. This would, however, double the gear ratio and require me to get the Long 16 cell chassis from Unlimited Engineering. With my current chassis, I don't have enough room to drop the motors down on each side. This would lower the center of gravity even more.
Right now I'm running a 23 tooth pinion with a 64 tooth spur. I can obtain a gear ratio close to this one by using smaller pinions. With me running this high of a gear ratio, you wouldn't think it would have enough torque to break parts. It would seem that it would take a long time to "ramp up" to it's top end. But IT DOESN'T!
I stripped out the transmission in 2nd gear, doing smokey donuts on concrete! This does tend to wear the tires out really quick too. LOL

Yes that is a receiver pack. It's a Lithium Ion 7.2 volt 2000mah pack. One charge in it, will carry the truck for about 4 or 5 hours or runtime. The Receiver and the servos benefit from the higher voltage. Traxxas under rates the voltage on those to cut down on warranty claims. But with this truck, I wouldn't say I'm "taking it easy" on any of the parts! LOL The steering is faster and the servo has more torque.
Those are aftermarket fans that put out more air than the novak versions. They move alot more air when fed at 7.2 volts also.
This thing actually runs pretty cool. This leads me to believe, that even though this gear ratio seems high, there's still more room at the top.
If anyone comes up with answers to my transmission problems. Please post!!!

You have two HV-Maxx's.

http://www.ultramaxxed.com/

I'm not sure if they are in production. They were very heavy, but unbreakable.

I say 50-55 MPH for your E-maxx once you get it together.

$200 Per Set???
WTF is that about?
They may be rock solid, but that price is obscene

I'm not sure if your aware, but these are exact CNC copies of the stock gears. They are highly complex, and they are big too. That price really isnt bad. If you were blowing stock gears with every thottle application, you would think the price is great.

7075 doesn't come cheap. That price is pretty high...if we made those we would probably only charge about $100-$125 or so. They are just praying on the fact that they are the only ones with such a complex tranny. Getting the stuff perfect on Autodesk Inventor is probably the most time consuming part of the whole operation. There are single speed steel conversions, but that keeps the 2 speed with stock ratios so it is a bit more complex.