MMM/2650 + Slash 4x4 = FIRE!!
 

I have been patiently waiting for the new Slash 4x4 to be released. When I heard about the Platinum Edition, I cancelled my preorder of the RTR and ordered the PE instead. I finally go the truck on Monday. Traxxas set the truck up to accept the MMM combo, so I installed a brand new MMM/2650kv combo from the get go. I connected a brand new Hyperion G3 VX 4S 5000mah pack. The truck ran great for about 45-60 seconds, then the ESC burst into flames. I've never seen an RC vehicle on fire before, but it was scary and the smell was HORRIBLE. Anyway, I was able to blow the flames out within about 20 seconds. I've included pictures below (cuz everyone loves carnage), but please also take a look at my questions.

1) What the heck could cause this?

2) Obviously the ESC is toast, but should I be worried about the motor? In the Slash 4x4 the ESC and motor are pretty close together and the endbell of the motor is blackened from the fire.

3) Is there any way to be sure my lipo is OK? It doesn't have any visible damage and it still reads full voltage.

http://www.nuibe.com/rc/slash4x4/mmm...mmm_fire_1.jpg
http://www.nuibe.com/rc/slash4x4/mmm...mmm_fire_2.jpg
http://www.nuibe.com/rc/slash4x4/mmm...mmm_fire_3.jpg
http://www.nuibe.com/rc/slash4x4/mmm...mmm_fire_4.jpg
http://www.nuibe.com/rc/slash4x4/mmm...mmm_fire_5.jpg

are your deans soldered correctly?


spin the motor by hand- if its obviously hard to turn (aside from the motors natural resistance- it should be fine. and if your lipo is not puffed and is still in balance your fine

Correctly? The polarity is correct. The solder joints seemed to be good. I installed them the same way as all my previous vehicles. Is there something specific I should be looking for?

I was thinking Polarity- might have been a fluke with the ESC. call castle creations- they will more then likely send you out a new unit.

Damnit, that sucks. Your motor and lipo should be ok. You might have just gotten a bad ESC. I bought my 2 combos from the same place and they seem to be working ok so far. I'd give Castle a call in the morning.

Sorry to hear of your misfortune and hope you get the answers you need.

What shocks you running, I seen Green Losi springs in pic #2 ????

8ight's

I've installed shocks from a Losi 8ight 2.0 buggy.

Bad luck, the MMM is a nice ESC when it's working, but it seems that when they die, they die in a rather well, explosive fashion, and when it's right next to Lipos and a not so cheap motor, that can be dangerous.

Unfortunately with any warranty claim comes disappointment and resulting downtime of an rc you're probably pretty eager to run.

Lets hope Castle can help you out on this one, they read these forums a bit, strangely they never seem to reply in one of these threads regarding a failure of their esc though.

conspiracy theory here. castle will take care of you. they know they have failures and stand behind their product, and I stand behind them.

well, if I could stand:whistle:

Certainly no conspiracy theory, just an observation.

But I can see that commenting in a thread can open a can of worms from liability to making a judgement on warranty without seeing the unit etc etc

My thought exactly. I'd rather have them deal with the person individually. Castle will stand by their products. I had my own experiences returning burnt ESC's and I'm very satisfied with the customer service Castle has.

to the point- I would guess a binding in the driveline somewhere, or too tight a gear mesh.

It's really hard to say what the failure could have been. Maybe a fluke?

send it in...their customer service is awesome... :)

I hope it's a fluke. The truck rolls nice and smooth and the gear mesh wasn't too tight. Maybe something came loose on the board or something.

I've seen patrick poke his head in a thread and say "send it on in and tell em I said so".

Sorry to hear about your misfortune.

Unfortunately, at these power levels when anything goes wrong, the ESC usually takes the brunt of failure -- and at these power levels the failures are usually spectacular. :oops:

It sounds like the ESC took the damage, I wouldn't worry about the motor -- it's probably fine.

If you Lipos show normal voltage, they are probably fine too.

Contact tech support by phone, and let 'em know I told you to call in. We'll see if we can expedite your service.

Thanx!

Patrick

Thanks Patrick! Given the relatively light weight of the truck (5 lbs or so), this must be a fluke right? I mean, the connectors were on correctly and the battery has plenty of power for the setup. I just want to make sure I don't need to baby this setup in the future to avoid any issues.

Hard to say for sure what went wrong -- but we see a small percentage of "infant" failures where an ESC will fail for no good reason. Usually those failures can be tracked to a failure of a single MOSFET, which cascades through the ESC. Why the single MOSFET fails isn't always obvious -- can be caused by a cracked solder joint, a bad circuit board, or a manufacturing defect in the MOSFET itself.

Usually the on-board protection (over current and over-temp) usually will prevent failures in most "bad" setups.

So it is probably OK to assume it was a fluke failure.

I had suspected, but are you using the 8's fronts on all 4 corners or the longer ones in the rear ? How did they work for you prior to your melt down ?

I am using buggy fronts in the front and buggy rears in the rear. The buggy rears are on the long side. This allows a bunch more down-travel than stock. I moved the bottom of the shocks to the farthest outside hole on the control arm, this limited the down travel to ensure there is no driveshaft binding. In the front, I am not completely happy with the setup. The front shocks are also a bit long and the shocks bottom out before the chassis does. This is just asking for trouble, IMO. I will probably make an aluminum piece to bolt to the front shock tower and raise the upper shock mount slightly, so the shocks will work better. These big shocks sure have some nice damping though.

Cool, Thank You much for explaining.
After Castle gets you a new ESC, when you get driving again please post shock updates.

Jeff

Thanks Patrick. I called in and spoke to a very helpful gentleman, who said I would be taken care of. Unfortunately, he said the MMM's are out of stock, so I have a bit of a wait. Any idea when those are going to be available?

Thanks again!

Yeah, I will use the downtime to get the front shock mount figured out. I'll report back once I have it finalized.

:whistle:

I cannot count how many times I have seen Patrick do this so the observation by fastbaja confounds me a bit.

So it goes, open mouth, insert foot.

Yeah its a fluke, i have been through no less than 4 MMM combos. Th first two died with in the first thirty seconds of their running in my EREVO before bursting into flames. The third replacement they sent me ran fine for weeks and weeks and than one day i put two fully charged batteries in, it armed and turned to dust. The latest one was my fault i took my DM1 out for some fun and forgot i had it geared for speed runs. It actually lasted a long time considering the gearing 30/44. It didn't catch fire either just sort of limped around like one whole phase of fets was gone. I paid for that repair.

With all the mentions of "it's a fluke" in this thread, there's actually a well respected NW electronics company called Fluke. LOL (named for the founder though).

Yeah, and they make great stuff -- we have quite a few Fluke meters in Engineering and some in production. Unfortunate name though...

Fluke can mean stroke of luck, or a parasite, or even fish fins.

Hi Patrick,

Any idea on the ETA to get the MMM's back in stock?

Who would've known!! :lol:

i killed my MMM, was running in deep puddles and to top it all off i was only running a 20C 5s zippy, and i left it plugged in!
i told castle this and hey STILL replaced it!! :mdr:

WOW was it 75 dollars or under warrenty?

they did it under warrenty :yipi:
castle rocks!!

Oh my gosh! :angel: I just accidently ran/crashed/dove/landed into a frozen pond with my MMM! It scared the poop out of me! It stopped the power but it works now after drying it off.

you go lucky sir.. im surprised it didnt smoke on you after shorting out... did your lipos puff?

I would also like to know this. Thanks.

Maybe a little late or untimely to ask but, The 2650 and 3s sound like a great power combo for the 4X4 Slash.
I know you only got 60 seconds of driving time befor your meltdown but, any positive comments on performance ?
EDIT; Sorry, thought your were runnin' 3s. I reread and seen it was 4s.

So castle is out of the MMM? I just looked on there site and you sure can buy one!

Yeah i like Castle's customer service for sure.