TrueRC 2X3S1P 5000mAh + NEU 1515 1.5D + MMM = FIRE!

[JaySki]

I said.. I agree with the Ripple Voltage being a possibility.. But there is more and more data popping up that supports that the Batts shouldn't have been an issue. You are right without a data logger. there is no knowing.. What I DO KNOW.. Is that they are BRAND and were never used Lipos. That the airflow is bunk excuse because #1 the windshield is cut open a fair amount and 2. I never got more than half throttle and didn't run long enough to even heat up the motor let alone anything else. It flamed while at a walking pace for about 5 feet. I HIGHLY doubt I need a data logger to determine if I exceeded 300Amps, etc.. Obviously.. something went wrong.. I think that is in agreement. My point is.. On Paper.. It shouldn't have cooked. Not that fast, under that little use... Not unless the ESC failed and not because, solely, of ripple voltage.

I only posted this here to share info.
I can be honest that I am tired of being a beta tester for this ESC. I have spent(as many have) a lot of money. I didn't cut corners to try and tape together a rig that should go fast. I bought everything that I could find that was in the upper ratings of being preferred stuff. I have maxamps batts, NEU motor, Medusa Motor, Phatlines, Badlands, Hyperion DUO charger, etc etc.. I have not abused any of my stuff as I haven't had a chance to really even run it for any length of time. I have spent countless hours resoldering connectors to eliminate any issues there.
Between BEC failures, Flames ESCs and all the other wacky crap with the MMM V2, there is obviously more issues than CC is admitting. I think the mere fact that 2 other CC techs have joined in here to collect data supports that they know there are issues that they know nothing about the cause yet.
Again a fire is not a simple bec failure, it is caused by overload.[/QUOTE]

[captain harlock]

Guys, I think the Neus are asking alot of things from the MMM.
I'd try the Mamba Monster with a LMT motor.

[VintageMA]

Originally Posted by captain harlock

Guys, I think the Neus are asking alot of things from the MMM.
I'd try the Mamba Monster with a LMT motor.

Yah know - it might be the opposite. I had a great 1/8 buggy setup on 5S with the MM and everything was all nicely in spec and temp ranges. As soon as the MMM came out, yes the buggy had more power and accel and speed - but - first run the Neu was hotter and the lipos were so toasty I was afraid they would puff.

It's an unexpected benefit of such a low resistance esc, but at the same time it's such a difference that it'll catch you without even knowing it.

Am I the only person here with my same original 2 V1 MMM's that hasn't had a single problem all summer?? I can't believe that. I haven't modded a single thing and have pretty much run the only on 6S with the BEC......

[jhautz]

you must be in the 98.5% that CC claims to not be having any problems.

LOL

[magman]

Vintage...I was running my v1 mmm on 4s w/ a 9xl and a cc bec. I recently switched to a 5s, reprogrammed the esc for 5s, ran it on short grass to test and it lasted 3 min before cooking the cc bec..

I did rewire the fan to the rx and cut the grill above the fan out.

[JaySki]

Originally Posted by captain harlock

Guys, I think the Neus are asking alot of things from the MMM.
I'd try the Mamba Monster with a LMT motor.

Hmm.. Then why would Castle be gearing up to make a package deal with a MMM and NEU motor???

[hemiblas]

I run the truerc cells and have tested them with my wattmeter on various setups. I have the 10C, 15C, 5000mah cells, 4000mah cells and the 8000mah packs at all voltages. I can honestly say the batteries hold their voltage very well, even better than some 20C packs I have bought. Its not the batteries. If anything these things hold their voltage so well you are getting some serious power to the motor. My BEC failed on my MMM. I think it probably had more to do with the dual servos than the batteries being the problem.

[GT35R]

Don't forget that an ESC is worked harder on partial throttle, so you really need to know
how much current is being drawn at full throttle/load and allow some headroom above
that regardless of how much trigger is used.

[hemiblas]

This is just my opinion, but the only 2 times I fried speed controllers is when I tried to do something similar to this. I overgeared and overvolted a couple of setups and I let the magic smoke out after running them for several minutes. I think this setup stressed the speed controller and caused it to fail. I dont think it was your fault though. With specs like "more than you can handle", it is implied that you can do just about anything and the controller should be able to take it. I have also read that the more efficient a motor is, the higher the instantaneous peaks will be.

well when i get moine back when it blow s up i hope your ready to mod it like that one

[SpEEdyBL]

I would have to admit that the caps the castle uses are undersized. Novak uses fair sized capacitors on all their escs. I'm not saying it wasn't an MMM related problem that caused the failure, but if you think about it, even though the truerc packs may be true 15c packs, thats still only 75 amps continuous. Castle claimed they saw 800 amp spikes in their setups during prototyping and that was probably with a 1y which is even lighter than a 1.5D. From my experience, I noticed a huge gain in peformance when going from 20c 5000 mah maxamps packs to neuenergy 30c 4100 packs. My novak hv4.5 turned into a completely different motor. It suddenly had more punch than my 8xl did and i could gear down 2 teeth on the pinion gear without sacraficing any top speed. Before I made the change, I totally judged the motor based on peformance since the packs were barely getting warm. Once one of the cells puffed, and then two more while the rest of the pack was sitting on the shelf, I soon realized that batteries are a HUGE factor in determining performance. This was only in a 7lb 8ight, so think of how much of a difference there would be in a monster truck that requires even more power for even higher speeds, with say 125 packs verses 75 amp packs.

[hemiblas]

SpeedyBL, You are right. Batteries do make a big difference. I had a setup on an 11.1V lipo and the wattmeter measured 10v dip on an 11.1v lipo. I tried a better battery and the wattmeter measured 10.5V dip. The total power difference ended up being 100watts. It was something like 550w vs 650w just from a different battery at the same voltage. I can only imagine if I had one of the neu packs, I could have picked up another 100w of power.

Jhautz, You should see the mtroniks truck esc. You have diodes and a cap all on top of the esc. Looks sort of like your creation. I like it though.

SpeedyBL, Thats a good point on the battery limitations. Even though the truerc packs are great cells, they are only rated for 75amps. Maybe as the pack drained a bit the cells had trouble keeping up wih the peaks and were no longer sufficient for this setup. I dont think truerc posts a peak for those cells either, but I think we can all agree that they would have exceeded what the pack could produce. Even their 10C 5000mah packs though outperform my 20 5000mah packs that I bought from another manufacture, but ya in this case it might have been asking a bit much.

[JaySki]

Good info.. Thanks. Learn a little more each day.. with hopefully less fire! :)

[hemiblas]

At least its all covered under warranty and you can get another one. Keep in mind that for every mph you try to go over 30 the running amps and peak amps go up by a lot. It just like with horsepower, with 200hp you can go 200mph, but with 1500hp you can only go 300mph. It takes much more power to go only a little faster. With these 60mph setups you need some serious battery power. Going from a setup rated for 4S to 6S to try out speeds is a good idea if you provide twice the battery capacity and power at 6S. I dont think our battery trays are big enough for something like this and the high end batteries are just way expensive.
I think the reason Novak has such success is because they package the motor and the esc together and you really cant change much and they dont have many motor options. With this sensorless stuff, the possibilities are endless and there are some amp hog motors out there that could cause some trouble.

[Semi Pro]

what i dont get is why are alot of people haveing problems with the mmm useing the say set ups that worked well on the mm with a fan and some caps?