Modded Mamba Max Testing!!

[lincpimp]

I recently sent Griffinru a MM and had him do his "stage 1" mods to it. Upon receiving it from him I had a good look at it. His workmanship is very nice and clean, all mods are stock appearing and well executed. Basically the intent of the mods is to keep the esc cooler and help it to handle higher voltage. My first tests are with 4s lipo, I will try 5s lipo as well.

Test vehicle is an OFNA MBX R2
http://www2.towerhobbies.com/cgi-bin...?&I=LXAXV2&P=7

The buggy has a feigao 7xl, RCM heatsink/clamp, 15/51 gearing, and 50k traxxas diff fluid in the center diff to assist in motor braking. I am running a UBEC(of course) and have the MM bec disabled. My testing are is blacktop, cement, cut grass and dirt. I ran it for 10mins and then used an IR temp gun to determine the temp of the batteries, motor and esc.

Round 1:
Stock MM with Integy fan spaced 1/4 inch off heatsink, Maxamps 10000 4s lipo. After 10mins, battery 105f, motor 140f, esc 130f

Round 2:
Same setup as above without the fan. Ran for about 5 mins and the esc was up to 160f, everything else the same temp.

Round 3:
Swaped the stock MM with the modded MM. No fan used this time. Ran this setup for 15 min battery 110f, motor, 150f, esc 135f.
I would say that my "seat of the pants" feel was better with the modded MM. It started from a standstill on ful throttle well, no cogging and seemed a little faster accel than the stock MM. The temps were great, the upsized caps did not get anywhere near as hot as the stock caps do. I will say that I am not impressed with the maxamps 10000mah battery. I did not get the run time that I had expected from it. All three tests were done on the sme pack, without charging it, si about 30 min runtime. It is new, 2nd charge, so I will run it more and see if it improves with a few cycles.

Round 4:
Tried some different batterys. Used the milwaukee lipo cells, arranged in 2s2p packs and ran 2 of those packs in series for a 4s pack at 6000mah. Got around 20mins out of that setup and the temps were good until I hit the lipo cutoff and tried to keep it going. Temps of the batteries went up a bit, but still acceptable. Motor got to about 160f,but the esc stayed right at 140f, caps at 110f.

Conclusion:
The modded mamba max worked very well. It remained a good 30f cooler than a stock MM and did it for alot longer than the stock one could have. No glitching, thermaling, and did not heat up as the batteries drained. I would highly recommend this mod to anyone wishing to use a MM at 4s in a buggy/similar sized wehicle. My buggy is heavy, especially with the 10000 maxamps pack in it.

I will continue to test this esc, and will run a 9xl and 5s on it soon to see how it copes with the higher voltage.

[lincpimp]

Heres pics, cause I know you guys will ask

[snellemin]

Thanks for the Review. Really great to know about a small mod like that made such a big difference in temps.

[zeropointbug]

That's great news lincpimp.

What exactly did Artur do to it again? The cap mod and what else?

IIRC, it was Artur that said have the cap right on the esc board, or don't bother?

[mkrusedc]

Thanks for the great info. Please post when you test w/ 5s or 14 NiMh. My OE MM wouldn't run these as being overvoltage. It ran 4s.

[jnev]

Thanks for the info. I think I'll try to send him my MM ESC as well soon. Those temperatures with the modded ESC are without a fan, correct?

[zeropointbug]

Without fan, yes.

Why oh why, can't a Quark run that cool! But I guess the benefits of having a Quark require some 'sacrifices'. :(

[lincpimp]

He did upgrade the three caps on the board, they are almost twice the stock size. The really big cap (1800) has short leads and is soldered on where the power wires meet the board. The also added a heat spreader to the backside fets and a heatsink to the cpu/brains. I was very impressed with the cooling, especially that it ran cool for so long without a fan. I have a few other stock MM and they do not run that cool with fans and in lighter vehicles than the buggy. Definately worth doing on a 4s setup, made a noticeable improvement on startup too.

[lincpimp]

Ok tried 5s with the above setup. Yes 5s on a 7xl, I figured that I would give the MM a workout. Well it works and worked well until a small piece of steel/metal found its way into the spur and locked the pinion to it. The buggy was probally doing 40 at that moment and it stopped very quickly. The MM let out some smoke and is dead

Took it out of the buggy and had a look at it. Nothing looked obviously burned so I plugged it into the castle link. Programming worked fine so I guess that a fet crapped out, or something else let go in the power supply dept. I had the throttle pegged when it locked up. I talked to Artur and have shipped it back to him to inspect. I will post again when he gets back to me.

This really sucks cause the 5s setup was working very well. No cogging from a standstill, great low speed control, no hestitation either. I only got a minute of running, but nothing was even warm at that point. If he can fix it I will retry with 5s on a 9xl with the same gearing. That should put it at about the same speed as the 7xl/4s combo. I will also set the mesh a little looser and keep away from my shop parking lot as there is all manner of crap there.

I was really impressed at the improvement these mods made on a 4s, high draw setup like mine, I really hope that it can handle the 5s setup as well.

[snellemin]

Sucks to hear that your new modded mamba smoked. Lets hope that it's not a total loss and that Arthur can fix it.

[lincpimp]

I'm sure that he can fix it. He knows his stuff!!!

[GriffinRU]

Originally Posted by lincpimp

I'm sure that he can fix it. He knows his stuff!!!

I am impressed with Mamba built-in protection!
It was a very short high current spike, which took out one phase, check the melted solder :) but didn't destroy the rest.

As for fixing I sent you e-mail with details.

[lincpimp]

Thought I might throw in an update.

Talked to Artur this morning and he will try to fix it for me. I f not he says that he might have another use for the "brain" PCB section of the MM. Should be interseting. I will be sending him another MM soon to do the stage 1 mod to. It worked so well for 4s that I may have all of my MMs that I use on 4s done. Also heard that Mike is having some 5s success with the stage 2 modded MM that Artur sent him. I am waiting eagerly for some posts from Mike

[suicideneil]

Thats fantastic news. All hail 'King' Arthur and his mighty esc mods!

Just for reference does anyone know where you can get compatible replacement fets just in case i need to repair a mamba max when they get out of warranty?