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

So.. My latest MMM HAD been running pretty well. Ran several packs on 4S, both TrueRC and MaxAmps. No problems.
Today.. Thought I'd show it off a bit to some guys I work with. Ran 4S for a bit and then decided to try 6S.
6S ran great and just absolutely out of control fast... for about 5 minutes.
It rolled to a stop.. so I ran over expecting to find a dead MMM, but the lights were flashing.. Strange.. I unplugged the batts and repowered it up. Tones sounded, 6 beeps for auto Lipo, final tones and hit the throttle. Body was still off as I suspected something may just be going bad here. Sure enough.. It rolled about 5 feet.. Massive Smoke and up in flames she went.
I can still smell the aroma of baked electronics. I got it all out fast enough that it didn't get a real chance to melt anything (LUCKILY)
Went back into the office and called Castle.. again... Tech support.. and dangit if I can;t recall his name.. wasn't Thomas though.. Any ways...
He inquired to what I was running, etc.. When I mentioned the TRUERC batts he stopped me and said.. "There's the problem! Nearly everyone of these that flame are due to the cheap batteries and TrueRC's are one of them". I told him that I usually run 4S maxamps and TrueRC and he said MaxAmps are much better as they can handle the current draw.
All of this really starts to contradict what goes across these forums.. and I told him that.. He said.. "You can't believe everything on the forums" to which i completely agree, but I do tend to look at feedback from masses and not just a single source. Most of what I read.. says Maxamps are typically over rated and TrueRC are more accurate if not underrated. He said he wishes they could put out better information but they can't regarding batteries and such. I said.. yea.. So do I.. as the only info is what we all share.
anyways.. Just wanted to share.

Yet another MMM down for me.. Now I am out of service and I have bought 2 MMM V2s. I shoulda just stuck with 4S.

My thoughts are the same as they have been, the 1.5d is too much motor for 6s especially in a monster truck.

PLease explain. Looking at Specs of both 1.5d and MMM, I shouldn't be outside of the parameters. and it shouldn't result in FIRE after about 3-5 minutes of maybe half throttle?
In all reality, 6S on that motor, I knew would be overkill, but I wanted to try a run on it. It was the first run.. Brand new batteries even.
I actually purchased the 6S for my Medusa.

What gearing was it running on 4s and on 6s?

21/58 and 16/58 respectively.

Were they the 10C TrueRC cells or the 15C TrueRC cells?

Were the batteries hot when it stopped the first time before the fire?

Seems strange, if the trueRc batteries were and they could not supply the current. I would think that would put less stress on the electronics not more...

On the other hand if the batteries catch fire then we can blame the batteries.


I have an eRevo geared 20/58 with a tekno 1515/1y 220kv and I run 4s 8000ma(15c) trueRc batts. I have yet to hit the lvc and I have driven on the track for ~30 minutes (the charger put 6000ma back in the batteries after this outing)

From what I have read the trueRc are at least equal to maxApms in current output and capacity.

I also would not be surprised to find that statistically more people with the MMM are running trueRc so his observations about failures could be true but not indicate and issue with the batts

15C.

Batteries were NEVER hot nor was the motor at the time of Flame. Motor was warmed up, I think Temp gun was 108, batts were 85, esc.. well On fire.

You are at the top line of spec only assuming adequate airflow. You must also account not just for rated current but stall current, spikes, and so forth.

The motor is rated at 120 amp and the controller at 120 amp with air greater than 500 lfm. Pretty tight when you look at it. Then factor in that with 0-200 lfm you get 70 amps, and 200-500 lfm you get 110 amps, you can see where the problem is.

Running the KV as high as possible is not the best way to get speed in a monster truck, you can't apply 10th scale or 18th scale formula's in a monster truck and/or 8th scale world. You are much better off to get a lower KV motor and gear down to attain the speeds you want. Then there is the fact the having a high speed setup on anything but the street changes the dynamics drastically.

Then there is my final note that your 15c batteries can't provide enough current for that setup. 15c at 5000 mah is 75 amps. You would need at least a 25c 5000 mah pack or at 15c an 8000 mah or higher pack. Cheap packs can damage the ESC as well.

Where I agree with where you are coming from.. And in in all honesty, running the 15.d on 6S is not on my list of normal activities. Brand new batts, Nearly new MMM, not abusive AT ALL. And actually never got past, say half throttle, and there is no way to even punch the throttle on 6S with the 1.5D and geared where I was... Current Draw SHOULDN'T have been real issue.. Setting all that aside...
Where did you find the MMM is rated at 120A? I agree running the 1.5D on 6S is on nearing the upper limits, but it still isn't over. If I was drawing too much current, the batts would have heated up.. or givin an indication of sucking too much out.
Add in the fact the truck literally flamed as the truck was rolling at a walking pace.. makes me question...
Additionally, CC saying TrueRC batts are the cause.. Wouldn't there be issues with the Motor or performance beofre the whole damn thing torches?

I've had 3 MM's go up in flames... 1 was due to a failed rotor - The others were the same setup I had previously used.

I concluded it was the "weak" batteries - When I added extra capacitors to the MM I have since not had an issue. I believe the issue is that under large amp draw the batteries voltage dip - this creates "voltage ripple" into the ESC that without suffecient buffer i.e. capacitors the ESC can't take it and basically self destructs.

I would guess this is what happened to you...

The damage was done probably when you pulled the trigger from stationary as this is when the amp draw hits...

ps that is the lay persons explanations - search on voltage ripple

Sounds more logical than the rest of the explanations.. The weak battery blame though.. Bothers me a bit. Guess I'll just chalk it up as a "once Bitten twice shy" event and move forward.

Interesting is now there a need to add caps to a MMM like we all used to do to the MM...

Maxamps are no better than the true rc cells, and neither is going to keep up with a a setup geared for 55 mph...

Sounds like you over amped the esc. Amp draw of the 1.5d on 6s with that gearing is going to be high. You may have a faulty fet, and that is what smoked. I would say that it would be better to gear the 4s setup up to reach higher speeds.

They won't rate it.. Say it's bullet proof.. and can handle more than you can throw at it...
Well..it IS bullet proof as it will never see anything though... as for handling anything you throw at is.. as long they aren't CHEAP batteries which no one can really determine.. unless that is determined solely by how much you spend on them(MaxAmps), don't change any of the settings in Castle Link, or use the BEC... :)
By the time this crap is even remotely headed to a resolution.. Winter will be in the air and it will be spring before the revo can come out and play again.

Then the dang thing shouldn't be rated for 6S and claim to handle "more than you can throw at it" Give me something to go by and to work WITHIN.

I agree with gearing for a bit more speed on 4S, but again, you start to deal with heat issues.. and running 55 more than a pass or two is .. for the most part.. Boring. It's not like you can really drive it around at 55mph. We can;t even really keep tires on them over 45ish without taping, gluing, re gluing, re gluing, etc...

As I said. My attempts with 6S were merely for a run or two geared up as far as I thought would be safe to keep the heat off the ESC. Even then.. I never opened up the throttle. You can't.. #1, torque is insane and won't keep rubber down. 2. Ya run out of space fast if you try and feather the throttle. 3. even if you have the space.. the radio distance will likely limit you.. or your eyes will.

Just out of curiosity, how long were your battery leads (from the battery to the ESC)? Schulze ESCs had a huge problem with this, and their manual actually said to add capacitors if the leads were long enough (because of voltage ripple).

I think Artc1k is onto something, that the MMM needs higher capacitance. Anybody know what capacitors and how many the MMM comes with?

Stock setup is 390mfd 35v capacitors. 3 of them

Funny, I just added a 2200mfd 35v capacitior to my V2 last night. The easy way to do it is just take the battery leads and solder it to the sides of the bullet connectors on the battery lead wires right where they plug into the 6.5mm sockets on the board. Thats as close as you can get them without actually soldering on the board and voiding the warranty.

I'll try and remmeber to take some pictures tonight.

Maybe 6 inches?

I certainly can't disagree with what Arct1c is saying of jhautz is doing.. Adding a capacitor to smooth out the voltage would work.. but why are we having to add components to a piece of electronics that claims to be able to handle what we are using it for??????

This whole conversation isn't to argue what I did wrong or may not have done wrong. To me.. it is looking at what I was doing that caused the catastrophic failure of the MMM. Was I within specifications? I think so. if I was borderline... then I could see a failure if I pushed too hard and for too long. Running the gearing I ran, on smooth pavement, for less than 5 minutes.. never getting to full speed, never stomping on the throttle or break... should NOT have caused it to flame. Considering when it blew.. It as rolling at a walking pace... otherwise.. I'd likely have a melted car and not just a burnt ESC.

I do agree that the MMM has been quite a disapointment... I just hope that they figure out what is up with the recent failures. Your sounds like a fet failure, those do happen, and not that frequently.

Jeff can you point me at those caps - I think I'll do the same - It worked a charm on the MM's

Dont let any of this bother you. There arent many that seem to be able to make these MMMs run for very long. I've been through 3 already myself.

Either of these should work. I used the Nichicon. Same one I have been using on the R1Pro.

http://search.digikey.com/scripts/Dk...me=493-1597-ND

http://search.digikey.com/scripts/Dk...name=P10310-ND

Thank you - That needs to be stickied!

I ordered 14 while I was at it as the same price as a couple of Novak 4s ones.... thx

14!!!! Thats gonna be a hell of a spark when you plug it in . lol

Well I have 4MMM's and my Q125 also only has a 25v one so I might upgrade...

You can't have enough spares -

While the MMM may still have issues, there is a big difference between a simple failure and a fire with meltdown. These are two different things happening here. As well there are specs listed for it here:

http://www.castlespecialprojects.com...ntrollers.html

I do not think all failures can be lumped into the same category as many are trying to do. My V1 failed and my V2 is holding up fine.

And up to 300AMPS in Burst (10 Second/1 duty cycle)
so.. again.. I am not out of spec..

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. :oh: I haven't modded a single thing and have pretty much run the only on 6S with the BEC......

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

LOL

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

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.

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.

You keep saying that but I posted how you were not. You used batteries that were not up to the task and a hot motor that without the proper airflow puts you way out of spec quickly. Without a data logger how can you be so sure you were in spec, how do you know you didn't have much higher spikes?

You also need to research ripple current as was suggested previously in regards to the batteries you used.

Again a fire is not a simple bec failure, it is caused by overload.

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.

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]

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.

any pictures yet

I still think you had a weak fet in there and you gave it a decent workout and it let go. There are going to be some fet issues, just a fact. If the MMMs were not having widespread bec failures, the few smoked escs would just be chalked up to having a few dud components.

The battery excuse is crap, all you did was give the esc a workout and it let go. I did the same thing to a MM once on 5s. I have a 7xl in a buggy geared for around 40mph. I decided that I would try 5s and did not gear down. I got a rock stuck in the spur and the esc fried. I had griffinru look at it and he seemed to think that a section of solder got too hot and bridged 2 phases on the board. He seemed to think that there was a bit too much solder on there. So a rock and some sloppy solder work caused mine to fail, but it was probably getting quite hot from the overgeared setup too. A collection of things were at fault.