BL Setup for Stock E-Maxx and Upgraded Parts Suggestions
 

Hi. I'm new to the forum. I've decided to go brushless. I mainly putts around parking lots and go flying around in the dirt looking for the big air. Occassional racing against the LHS employees dictate that I have some good speed too. I won't be upgrading suspension, chassis, etc unless I break something. The HV Maxx would be a decent choice for me but after reading a bit on this forum it sound like I could do better. I keep reading good things about the 9L/9920 combo so that is the direction I am leaning toward. I have some 6 cell batteries but they will get handed down to the kid once I get the IB3800 7-cell units. I like long run times. Specifically, my questions are:

Is the 9L/9920 the right setup for me? If a different setup is better, Why?
What kind of run times would I be looking at?
What upgraded drivetrain parts (like CVDs, steel gears, diferentials) do I need to get?
Would the stock gearing be sufficient? If not, what would be optimal?
Anything I overlooked asking about?

Thanks guys

Before you add too much speed, I would suggest you try for better control of the stock Maxx ,by upgrading the servo saver and the steering servo. Big power will not be fun without good control. The differnce in steering response and handling may surprise you. Check out the UE servo saver and a quality metal geared servo. look for high torque and speed.


Oh yeah...welcome to the forums.

Welcome MountainMax!

The 9920/9l is a good choice but a favourite setup here is also the 9920/7xl on 14 cells.It has a good deal more torque and the ability to run nicely on 12-18 cells.

Either set up will require some drivetrain upgrades.(both very powerful).You can wait till things break and upgrade but what i would suggest is steel idler gears,cvds,a strobe slipper and maybe a gorilla max single speed conversion.Then i'd run the stock diffs until they need replacing.

The strobe slipper is good because it can actually be used as a slipper (with slip) without overheating.they use the ofna 51T spur.the stock slipper has a tendency to overheat and melt the spur gear unless you run it locked down with extra pegs.

the single speed along with a steel idler gear makes the tranny very bullet proof.it's stronger than the 2 speed by taking the backlash out,more +ve engagement.you really don't need 1st gear with a brushless setup.
If you keep it 2 speed get a pair of steel idlers from Mike($15 each or $25 pair) as the stock idlers won't last long at all.

RC-Monster Mike stocks all these parts but can get just about anything RC related for you,just ask him.
He's very helpful and offers a very high level of support.

Gearing will depend on which motor and cell count you decide on.If you go for the strobe the ofna spurs are mod1 pitch but Mike sells mod 1 steel pinions in 5mm or 1/8th bore.

You may need an external battery pack or a UBEC on that controler. welcome and have fun.

If you go brushless either the 9l or the 7xl(gets my vote). You will need the steel idlers and cvds. Papa has a good point. Control is a lot. I did not believe the difference it made when i changed. The ue saver is worth the money to me. You can find the proline servo saver on ebay sometimes. Not as good but good for money. I not sure how stock your truck is. I hope this helps you out.
WELCOME TO RC-MONSTER FORUM.

You could also get the Kimbrough Saver here from Mike, along with a nice Bluebird servo.

I agree with the other guys. Gustavs post is nice and complete.

Welcome to the forum!

I have a jiffy question about what seems to be the prefered setup, meaning the 9920 and a 7xl, this is the same setup that was suggested for my truck, my truck is definately heavier than stock (UE chassis, GA bulks, UE wide track suspension, UE SS) Monster Mike was the one who suggested this setup for my 11lb truck......what I'm wondering here is if this is the right setup for my truck (I'm betting it is, cause Mike sugggested it....) then would it be over kill for a stocker like the one in this thread.

To my way of thinking (I am by no means an expert, that's why I come to this fourm for help!) If that setup is good for my truck, it would be over kill for a stocker, or if it's the right setup for a stocker, it's going to be under powered for my truck.

thanks all!!

The 7xl with 9920 is a very versatile motor. It will take form 12-18cells. If you truck is lighter you can gear it up get more speed out it. Truck is a little heavier put a little bigger ratio less speed. I ran the 7xl on a emaxx at 14 lb. Had no problems. Even had it geared a little high. It just went. Got a little warm though. It is a excellent motor. How many cells makes a difference to. More cells the more power. More volts = more rpm = more speed. Hope this helps.

On the long run, a proper set of diffs and dito CVD's are worth the invenstment as well..

The most wise thing to do is to drive it till you break it.

I too would change the radio/servo/saver part.

My choice would be the 7XL as well.

Proper batteries are also needed for BL, because the motor isn't any stronger than the energy the batteries can produce!

You have correctly applied basic logic. :-)

With the variety of factors that effect performance a single motor may have more than a single application. I wouldn't recommend the 7XL in every application (like say a 20+ pound truck), but it is viable for a 12 pounder w/ the proper gearing, batteries, and speed control.

There may be a better motor that will put you in the "sweet spot" based on what you wanna do w/ your truck (race, bash, rock crawl, high runtime, high speed, etc.), depends on many factors. After all, you don't see 7XL's as the recommended motor for 1/10 two wheel drive trucks. W/ the weight of the 1/10 trucks the 7XL has too much torque, which would mostly be wasted in this application (unless you need said truck to go very slowly up a 45 degree bank towing a brick).

Will the 7XL and 9920 be perfect for what you wanna do? Dunno (not sure what you want to do w/ your truck), but it'll probably work just fine.


Hope I didn't muddy the waters. :D

Thanks for the input everyone. Good stuff. One thing I didn't mention is a trick I learned from modifying my truck/Jeep/ATV/snowmobiles is to figure out where you want your machine when its finished and build to that point. It a lot cheaper, for me, in the long run because I'm not constantly doing minor upgrades and pitching used stuff in the trash. Using my sometimes irrational logic, I would probably want to do a majority of the upgrades upfront. Downtime with broken parts kills me.
After exhaustive reading I'm also considering an Evo. Realistically, how far is RC-Mike from releasing a product for the average DIYer to bolt something together with a Revo chassis?
I'm sure proposing a Revo roller sale to the LHS will just produce a few blank stares, but maybe I can bolt the spare parts to a rollerblade or something (just kidding! Please, no replies on the problems associated with that idea).

Thanks again everyone for your input.

Not long now!http://www.rc-monster.com/forum/show...5&pagenumber=1
Mike says here he's also planning on planning to sell Revo front rear end assemblies so no need for Nitro powered roller blades!

I feel lost...
 

I'd like to know if two brushless motors are better than one, or would it be a waste of money?:P:

I want the 4-battery chassis, two brushless motors/ESCs, and 4 3700mAh batteries (No lipos for me), but does that sound ridiculous?:o

I put a good deal of aluminum on my E-Maxx, and I have lost speed and CONSIDERABLE run-time. It breaks my heart. :M:

I would take one big motor over two motors every day!

welcom aboard icecream. I think the single big motor will out perform and run longer than two smaller motors. I run one motor. It is cheaper to run the one motor than two.

Oh, didn't realize this was your first post:o

Welcome aboard!!

...that's good news.
 

Yes, I'm new to the forum, new to electric rc, new to the E-Maxx, and I have no real concept of brushless motors.

The real reason that I wanted to run two motors/ESCs was because each can handle two battery packs, making four total. Is there a way to run 4 battery packs, with maybe two speed controllers for one motor? I like the 4-battery chassis, because it seems like it will hold enough battery packs to give me extra long run-times.

(Can you tell I'm new to electric?):rolleyes:

You can run all four battery packs on one motor if you get the right one. You can also get a controller to run upto 36 batteries. I run a single motor with 18 cells. I get about 30 min run time with gp3700. I run a all aluminum emaxx.

Now, that's what I'm talking about!!!
 

At the risk of being nosey, could you tell me exactly what you are using, coolhand? I hate to be a copy-cat, but I do want the same results that you are getting. :D

Coolhand uses a 9XL with a warrior 9920. Right Coolhand?

Nothing wrong with copies Ice, better reuse a wheel than invent it again.. :)

Welcome to this forum bytheway! You didn't get any email/PM from Ncabz yet? he is desperately hunting for new/fresh victims that can sell him a seccond hand 9920.. ;)

I run a 9xl nemisis. I run a schulze 1897 controller. I have run the 7xl as well. I get some good speed out of it as well. I would guess about 40 mph is my speed. I want to try my 9xl out on 20 cells or so. I got a new esc coming. Hey I don't blame you for copying me. I would copy you if you had a set up that I liked. I am going to change my motor out for a lehner 22 series before long. I want more power. Not that I need it. The truck has enough power to spin the 4 tires over on cement now. If you got any questions please ask.



All but the 9920 part serum. Not that I think the schulze is better. I did at one time before I owned it. I have it so I going to run it.

How does the 9XL perform in comparision to the 7XL on 18 cells?

Can 18cells on a 7XL take you past 50?

Yes, they can Nick..

*Slightly off topic*

Could a 9XL be run on a 7020 with say 18 or 20cells? I know its right on the boarder of the controller specs, but could it be done? Thanks

Wow! 50 mph?!!
 

I have an FG Monster Beetle that will go about 50, but it scares me...I'd hate to lose control or flip at that speed!:eek:

The stock E-Maxx is fast enough for me with 7-cell, 3800mAh packs, but the way I understand it, they cannot be charged as often as the 3700mAh packs. :C: I am really not interested in anything other than longer run-times, but I know that a brushless system will provide more speed and tourque whether I need it or not. :cool:

Thanks for the information, everyone. ;) I'm glad that I will not have to sell my aluminum in order to recover lost power and playtime, but I will definately have to sell some of my other RC stuff to get the set-up that I want. (My wife will not let me spend any more money until after Christmas. :M: ) Bye Bye Monster Beetle. :Love:

Jason

Do you mean he has a second-hand 9920 that he wants to sell?

With the proper gearing the 9xl probably can be run on a 7020. I ran a 7xl on a 7018. It did not last to long but I had the truck over geared as well. I think you be better off on a 9920. I figured it up on the emaxx scale some one had posted. I had my maxx geared for a top speed of 62 mph. It would run with traffic on a 55 mph highway. So yes the 7xl will push the truck to 50 mph. I want to try and push my 9xl some to see what I can get out of it. 20 cells and some gearing. I should be able to see 60 mph again. I really need to stop tire ballooning though.

At the flip at that speed. It is what killed my 7xl. I was blasting it down a field. The front tires looked like a boat across water(just skimming the ground). Air got under it and bam. That parts went to flying. I guy got it on video. I just can't seem to get it from him. I want it to.

serum means that he wants one.

I have a 9918 that I would be glad to sell cheap!!! It's sitting in Mike's shop somewhere and it's in desperate need of a new board. I would also like to know the gearing on the 9XL pushing 60 or even 50MPH with standard diffs and tranny gearing? Allthough I can see a disaster in the making!!

that was 7xl with stock diffs. 22 66 on 18 cells

How on earth did those diffs survive..

Wow, how quick did it go?

robinson gears with aluminum diff cups. They tougher than you may think.

I could drive beside cars on the highway by my moms house. The speed limit was 55mph. Everyone usually drives closer to 60. I wish i had shot it with a radar. I wanted to try a 24 66. Lost the 24 tooth pinion first run. didn't tighten it up.