Dual 5700 Kv Mamba Maxx
 

Hey y'all,

Been off the forum for a little while...been traveling for work. Anyway, I wanted to show some pics of an experiment I am working on. I know I am certainly not the first...and I know that many have recommended against it, but I wanted to see for myself. I am still waiting to order the batteries...probably going to go with two high quality 3S Li-po or two 11-cell Nimh...just haven't decided yet. If I am not happy after the experiment, then I will proceed with the original plan of the Quark 125B, Neu 1515 2.5 motor, and 5S Li-po.

Here are a couple more pics...

I think dual 4600kv motors would be better, but a cool experiment none-the-less. I would really be interested in a video of it running. I'd recommend 2 3s packs over 11 cells. It will be easier to fit also... and lighter.

Thanks for the words of encouragement...I have tested it with two 7-cell nimh packs and it performs well so far. Once I get the 3S Li-pos I'll try to get a video for those interested.

....I am using a BEC...I wonder if it would be okay to run it on two 4S packs. Afterall, that would only be .4 volts more than the Mamba Max is rated...:027: :018:

Nice. Let us know how temps and runtimes are with the dual setup. Bet it goes like crazy.

Hey. Nice to see we have something in commen. I am doing pretty much the same thing with 2 MM 6900 systems.

I am am not as far along as you are mostly because I have been waiting for the U.S.P.S. to deliver my order for 18 days now. It's coming from AZ. and I live in CT.

I will not be using the Gmaxx chassis (your looks good every neat) Will be doing FLM. Good luck.

ssspconcepts actually is using the FLM chassis. :)

WoW, I would like too see the vid of that thing running.

I think it's an amazing truck. Looks great!

How is it running for you??????

Thanks.
 

Hey guys...thanks for the kind words. I know a lot of the guys on this forum have a ton of experience and have recommended against going the dual route. I just had to see it for myself. I must admit that I was a little discouraged after I purchased the Quark 125B and was getting ready to buy the Neu 1515 2.5 motor. I ran the calculations and was shocked to see that my truck was going to top out at around 30mph. This was partially due to the fact that I purchased truggy diffs and pinions...but still...30mph?!? changing out to buggy diffs would have gotten me an extra 5 or so mph. So...I had one mamba laying around and got a killer deal on the other. If I am not happy with the results, my longer term plan will be to install the UE diffs and Neu motor.

I have heard that johnny maxxima has had good results with his dual brushless rig.

Well, it runs fine on my Nimh batteries....but it craves more voltage/current. I am getting ready to order Li-po batteries...but along with that comes a new charger, balancer, $$$. It will run off of two 3S or 4S batteries (parallel), which will feed the two Mamba Max ESCs (also wired parallel). It is the same setup scheme that Castle used for their barbie jeep and escalade on their website.

i would not use anymore than 3s lipo with the mamba 5700 motors.

have you tried gearing up to see what ratio these dual motors can pull?

edit:
also you mentioned that you were discouraged by the top speed you calculated with the neu quark setup but surely you know that you can gear such a setup to hit 50mph easy as long as you have decent lipos.

Have you tried gearing up to see what ratio these dual motors can pull?

Yeah...I have done some experimenting...but it is hard to tell because the packs I have right now are considerably less powerful than the lipos. On 8.4 Nimh I am geared at 22/66 and the system is cool as a cucumber.

"Also you mentioned that you were discouraged by the top speed you calculated with the neu quark setup but surely you know that you can gear such a setup to hit 50mph easy as long as you have decent lipos."

Yes that is what I am told, but you can only do so much with gearing because you reach a point where the NEU motor bumps/touches the emaxx transmission case and the pinion won't make contact with the spur. Its also been my experience that if you go too low/small on the spur and too big on the pinion that the motor will not perform so well...I don't know a lot about the Neu motors but it seems that they would be prone to the same effects as others. If you know of the specific gearing that hits 50 Mph with the Neu 1515 2.5, Emaxx tranny, and HPI Pro diffs, please let me know...the thing that is hurting me is the 43/10 diff gears. I wanted to try this (dual Mamba) first...before I rip all that apart again and start replacing my brand new diffs. As I mentioned, there are discrepancies and different points of views on the whole dual brushless feasibility and efficiency...I just want to see it for myself. If for no other reason than the numbers are very compelling:

Dual Mamaba setup:
11.1V X 5700Kv = 63,270 RPM

Neu 1515 2.5 setup:
18.5V X 1700Kv = 31,450 RPM

i would not use anything less than 8000mah lipos for that dual mamba setup.

I was not aware that you have problems using larger pinions which is a bummer as motors dont tend to really like going 63krpm without getting pretty hot.

Agree...I plan to use high quality lipos...but also they will be wired in parallel so there are some benefits in that regard.

As for the 63K...agree there too, but Castle rates theirs at 70K (or 75K I can't remember at the moment). Just because that power is there doesn't mean the motor will be turning at 63K the whole time---restraint my friend :027: ....besides the same thing happens (heating) if you use too large a pinion and too small a spur (plus improper gearing can also cause cogging).

New paint for my dual maxx
 

Well I received my dual flightpower 3S 5000mah lipos (to be wired in parallel to dual mambas 5700kv in parallel) and new MRC 989 charger. Getting closer to finding out what dual bl can do. Hopefully I will have some result to report this weekend. BTW, here are some pics of my new paint...FranksBodies did the paint....I can't take credit for his art.

That's a really sweet paintjob!!

Looks great SSS! Let us know know how it runs as soon as you can. Are you going to swap tires for your speed runs? Those puppy's look like they will baloon pretty good.

I've been testing a Mamba Maxx with 5700BL motor with 3S lipo the MM esc gets too hot and shut down after about 5 mins Temps get around 125F. Is the setup under sized for a Emaxx or would a cooling fan on the MM esc help from shutting down? Motor runs cooler about 85F but I have a cooling fan with heat sink on it. Also I use the Ubec from the MM would it better to have a seperate Ubec?

That set up is WAY to small for an e-maxx. The ESC would work, but I am not surprised the motor is getting so hot. It is designed for a light 1/10 scale 2wd buggy or truck.'

Getting an external BEC will definitely help.

pics don't work for me, I wanna see!

http://picasaweb.google.com/ssspconcepts

use this

Boy, this is sweeet! Man you did a good job on this. What do you think this will cost at the end?

Hey all,

Thanks for your continued interest and for keeping this thread alive.

I have been really busy with a new assignment at work and my time on the forum and with RC Monster Trucks has been limited. I essentially built two very similar trucks...one with a 4.5 Novak (with combo bulks & 1/10 hardened gears) and the other a Dual 5700kv Mamba (with hybrid bulks & 1/8 hardened gears).

About two weeks ago I took the Novak truck out for one serious bashing session in order to push it to its limit...the 1/10 diffs failed. Since then I have done an extensive rebuild and have replaced the diffs with UE spider 8 gears. I also replaced the two-speed tranny for a G-Maxx single speed tranny with metal gears. I have also ordered a Neu Motor and will be replacing the Novak 4.5 system with a Neu/Quark 125 combo...all to be powered by 5S lipo.

I want to compare the two trucks and see which performs better. It won't be long now.

Sombody asked price...yikes! I HAVEN'T KEPT TRACK, BUT I'D SAY IT IS SAFE TO SAY THAT EACH TRUCK IS WELL OVER $2k (not including radio gear).

Temps
 

BTW. Somebody asked if the dual Mamba system gets hot....yes it does. However it doesn't get any hotter than my single 5700kv Mamba powered 1/10 stadium truck used to on 3S.

The dual system runs dual 5700KV Mambas in parallel and dual 3S FP lipos in parallel. Power and speed is incredible.