CEN Genesis .46 nitro to Electric Monster Conversion

[Major Azzwoopin]

Hey fellas got a few questions I hope some of you might be able to help me out with.
I have a first generation Genesis, I have never been able to get the .46 to run very well reliably. It seems that everytime it seems to be running good it usually overheats because it is running a bit too lean. Outside of break in I have never been able to run a whole tank through this thing, without it either overheating, breaking, or jusplain old running too poorly. I have had little or no problem out of my CEN CT4S, CEN fun factor stadium truck, or my Savage 25.
Anyway this last week, as I was waiting for some new parts to show up, I was thinking about how to make this thing more reliable, more fun, easier to use, and more powerful all at the same time.
I think I am going to convert my .46 Genesis to an ultra high end electric monster.

I have been doing some research on the high end electric motors, batteries, and ESC's.
I am hoping that someone might have some practical experience with a heavy (17lbs) electric off road of some kind, that they might share some information about.


Seems like motor wise there are 2 options..
either 1 monster motor and speed controller
or 2 big motors and 2 big speed controllers.

Initial thinking is that I would stick with the Genesis drive train and steering arrangement. I have demolished a couple of spur gears, at least 2 pairs of differentials, and one entire transmission. One set of each was my fault. ( I ran a half a tank of 30% nitro through it)

From all I have read it seems that Schulze is the best speed controller around. And as for motors, either Lehner or Plettenberg seem to be the tops.
I am thinking either the lehner XL series or the Plettenberg freestyle 3xl
I haven't found a good description of electric motor characteristics comparing the electric specifications to power like torque.
Goal= A very snappy quick response truck that has a strong top end say maybe 50mph (should not be too hard with the Genesis's 3 speed tranny)
Also good reliability and 20+ minute run times.
What is the best Lehner for heavy eight scale truck??
best PLettenberg?/
LIPO batteries for sure....extra cell count will give me more??? (torque, power, rpm's, run time) extra voltage rating will give what?? (torque, power, rpm's, run time) additional MAH rating ??
Shulzle ESC??
What about 2 motors vs one??

HELP me please..Thanks.
Any thoughts guys

[RC-Monster Mike]

That truck is going to need a serious motor and some serious voltage to get 20 minute runtime and 50 mph. Are you planning on using the stock brake linkage? Also, I need some info to try to determine the best motor for this beast, such as diff ratio, transmission ratios, tires size, etc.. Then, I can possibly make a few suggestions for you. I think you will need more than the basic xl for this beast. I can get the higher end Lehner stuff, which will be a necessity(need a larger motor!) for this heavy beast of a truck. I don't know if the drivetrain will hold up to the power of a 50mph brushless setup, either.

[Major Azzwoopin]

Well I am not sure of the detailed specs of the differentials and transmission gears. I have been in contact with the CEN engineers, and I am sure that I can get those answers in the next few days. I currently am running the Genesis wheels and tires. But plan to put on the OFNA (part 86065) diamond rims with 17mm (part 36054) hex and 8 mm axle openings. I should get my set of ing on going with the 8.5 inch tall Jumbo Kong Tires. I have like 2 full spare transmissions I got on ebay (annhilated 1 tranny and 2 differentials with 30% nitro) I also have a significant stock of other parts.. If I need to bail on the genesis transmission and diffs, I can do that also. I am not opposed to changing those components (or really any other). I like the larger size of the Genesis over say a savagebut if it isn't a feasible goal I can try something more reasonable. Brakes will almost have to be redone, the stock brakes are weak. The drive shaft to the front differential will need to be changed from the carbon fiber junk thing that CEN used, (the end spins off too easy) a steel dogbone should have been used on the front like they used on the rear. The differentials are weaker than the transmission
So I guess 50 mph was a goal, but like any new project decisions have to be made and tradeoffs always occur.

Let me know what you think.

I am still researching about the electric (batteries, LIPO and others)powered and brushless setups to better understand the engineering principles behind these power plants and electric drivetrains.
I am trying to understand how the brushless motors ratings relate to power (torque/HP/and RPM) How different power source voltage, amperage, and mah ratings affect these same characteristics.

[Major Azzwoopin]

I just ordered one of the new HITEC robot servos 5995 for a steering servo, it should be here in a couple of days. I already have the programmer to get it set up. If those jumbo kongs are tuff to turn still, I may go with 2 of those robot servos sync'd and mixed one on each front wheel.

[supermaxx4190]

if you think 30% nitro was hard on the drivetrain, and it had enough power to blow out trannys and diffs, brushless will blow the truck apart. why dont you just buy an emaxx?

[Serum]

In germany, they made a brushless CEN .46 go 101 km/h on 20 cells with a lehner 2280 motor (4000watts) i think, the thing you are looking for is absurd in a monstertruck, and on these tires you want to buy it is impossible to drive 50mph. You need to get another set of tires and give them an anti balooning treatment.

I would get a savage, it is proven tough, with some modification in the drivetrain, you will be able to run 50 mph (and the truck is lighter as well) if you allreade wasted those diffs with nitro, stay away from brushless then....

One big motor is more powerfull than two smaller ones. a 2240-2250 is a better motor than the XL serie, it has got a higher efficency and will have got more torque.

From all I have read it seems that Schulze is the best speed controller around.

You did not searched on this forum for sure.. The BK 36150 or 36120 is the controller your looking for. ever seen the size on the bigger schulzes? if you are planning on going big, get a stable setup, something like a 36120 and a 2240/2250 motor.

Lipolys are nice, but you are looking at an 360 dolllar/per batterie setup pricetag (8S kokam 3200's 20C) and you should get a charger as well.
Those batteries will be able to deliver 1800 watts.

[Major Azzwoopin]

Thanks guys great points. Some very imortant things I hadn't considered, and some things I had hoped to figure out a way to resolve.
Is the E-Maxx drive train that much stronger than say a Savage or other nitro ride?
I already have a savage 25, I could do an electric on that. I would rather do the Genesis but it is an option. An absurd ride is always the goal anyway right.
Any suggesion on non ballooning tire setups??? The stock low profile CEN tires balloon like crazy on nitro. I hadn't really considered the ballooning affect as a major obstacle yet.
Battery price is not really a big deal. I have spent probably close to $1800 to try to get the Genesis to run reliably on Nitro, with little or no satisfactory results. As a Nitro ride it is a massive money black hole.
2 ways to look at this either the Genesis sucks and can't be made to run, hold up, and perform reliably, so it should be scrapped. And I should start bulking up a different vehicle for this electric idea.
Or the 2nd, the Genesis has potential and needs some help in certain areas.

I had been approaching this from the second

Important vehicle areas are: Transmission, Differentials, Dogbones, Brakes, and Tires

So what do you think...Trash the Genesis and start with something new??

[maxxdude1234]

Originally posted by Major Azzwoopin

So what do you think...Trash the Genesis and start with something new??

Personally I would. You'll be looking at 500$ for the speed control, 300-350$ for the motor. A set of lipos for that beast will set you back around 300$ aswell. Plus any drivetrain upgrades (which you will need).

PERSONALLY I would look at a second hand maxx, get a brushless set-up (9918/9L, 7018/2000XL etc.....there are so many). Upgrade the drivetrain to bulletproof, and buy any gorillamaxx/supermaxx stuff as neccessary...but that is my point of view.....;)

[Major Azzwoopin]

Hey Serum,
Did those guys that built that electric Genesis, discuss or post on any forums about their project???? I wonder what percentage of original parts they stuck with and how much they had to replace.??

[Serum]

Yeah, nothing on the drivetrain though. It's all in German..

upgrade the diffs of your savage with HB lightning diffcups (no aluminum) get a set of the GPM diffhousings (no other brand makes them) get a set of good CVD's and the new heavy duty 2nd speed gear from HPI.. it will be a blast on 18-20 cells. I would personally go for the savage, as i know it's proven tough. and it can be made electric very, very easy.. the maxx can be made tough as well, but it takes much more money than the savage. Here is my savage on 16 cells only. those 2 or 4 cells extra can throw out 2-400 watts of extra power..

this is the link to the German forum, you need to register though.

[Major Azzwoopin]

MIKE<
The Genesis gear ratios are:

1st 24.899 43/17

2nd 18.281 39/21

3rd 14.168 31/20


This is the list of ratios for the CEN 3 speed transmission in the Genesis now. They also sent me out a pair of the 6 spider differentials one front and one rear since I had one of the first batch trucks. They may be able to handle some brushless torture..
Also related to the 3 speed tranny exploding I think I figured it out. The original CEN radio and receiver were "glitching" throwing the forward and reverse off and on which most likely knocked off a few teeth and caused a meltdown. Different radio and different receiver new transmission and diffs and all is real solid right now.

Here is what I think I would like to try.
Cen Genesis chassis
one of three transmission options
1. use cen 3 speed (I think the 3 speed tuning will be a royal pain in the arse and clutches wont last long probably)
2. a significantly strong two speed tranny of some make with manual shifting ( I kinda like this one, good all around gear for bashing and screwin around, and high speed gear for open running or on the road or parking lots) I have a link for one without reverse at work I forgot to email it home
3. Or just one strong all around single gear tranny like the
Gorilla Maxx single speed transmission conversion (e-maxx)

The Genesis comes with 6 gear spiders now I can use these or go with an 8 gear spider diff from ultimate engineering or something similar.
I can stick with the CEN shafts except for the plastic (carbon fiber) shaft from the tranny to the front diff.
Steering is taken care of with a Titanium geared digital programmable Hitec 5995 robot servo it should be here by wednesday, I already have the programmer
Next, which brushless motor and controller???


More realistic goals:
I would like to get 15 minutes out of this beast but and LI POLY price isn't a big deal
Top End=transmission options 1-3:
option 1. Adjustable as long as clutches hold up??
option 2. 2 speed tranny probably upper 20's maybe 30 ish in low and who knows in 2nd
option 3. single speed one gear probably 40mph is a good goal

[sforsancho]

I can't help you with the brushless questions (sorry! )

but in regards to the 6 spider versus the 8 spider, here is a thread on the UE boards regarding the differences: http://www.unlimitedengineering.com/...&threadid=1867.
Personally, I'd take the 8s, especially with the off-the-line torque of a BL motor, you don't want to ruin the day with a broken diff.

On a side note, Isin't CEN releasing a 2 speed for racing?


*Edit: I was thinking about getting that servo (HSR-5995TG). What is this programmer you speak of? Something you need to set the EPAs of the servo?

[Major Azzwoopin]

The hitec 5995 robot servo is by default programmed for a robot application. I guess that for whatever robot function this servo was engineered for it is by efault made to rotate 180 degrees upon command input. With the HITEC HFP 10 (digital servo programmer)(i think)( I'll confirm in the morning for you.) you can custom program start and stop points for your custom servo needs. Meaning if I want the servo to rotate 125 degrees starting at x and ending at Z I can do that programming myself.

Usually with un programmable servos you must make sure you buy a servo that reacts exactly as you need it to. Now with the digital programmable servo I will be able to program my steering servo to hit the left steering stop and the right steering stop. should make for much better turning.
And on my existing receiver I am running 7.2 volts (not supposed to do that, is what everyone keeps telling me) so I should get some good muscle out of that new high voltage servo.

[Major Azzwoopin]

I forgot another thing. In addition to which Brushless motor and ESC would be how many lithium polymer cells and in which configuration?? I was thinking eitehr 1 5s5p or one 2s3p left side and one 3s2p on the opposite side connected as 5s5p overall. Is there a power consumption chart that any of these brushless motor companies have come up with?? or maybe battery companies?? Man with the amount of power that will be in those batteries I might have to wear an anti radiation suit..LOL
I'll propably wreck it on the first run and leave a 10 foot crater in the ground and a small mushroom cloud..

[Serum]

Here is what you need;

a 2240/11 with a 36120 controller and a 8S3P pack.

no doubt about it.. And don't come here telling your diff/drivetrain died...

You want to go absurd, i would love to help you out.

It will drive about 20-25 minutes, (or even longer)

for the numbers;
Use Kokam 3200 cells. they can throw out 5600 watt in the 8S3P configuration.

Your truck will fly and you won't be able to drive it WOT.. (but that's what you are asking for.. )