MMM v3 flameout - 2nd drive EVER??? :(

[BrianG]

lol, good catch. Judging by the heatsink config and the number of layers, I'd say that was either a Phoenix HV85 or one of the regular Phoenix ESCs.

[BL_RV0]

That car is crispy...
FWIW my MMM on 6s has been nothing but perfect. The switch failed but who cares.

[primus95]

I agree my SideWinder was awsome on 2S. I've got a response from Castle which is really good offering to pre-ship me a unit prior to sending the smoked one back, so that's one positive.

I have however posed some genuine concerns to them regarding the unit as a whole which I shall await their response on.

Whats the likelyhood of this happening over and over again (This unit has
had 20 mins runtime on it)?

Can the Monster ESC reliably run over 4S Lipo (I thought considering its
rating for 6S that my 5S choice was concervative and a good medium ground)?

Is using ESC braking a potential issue in these uinits?

Is there potettial that the ESC smoking has damaged my receiver, servo's or
the engine as looking at the case of the ESC, there been a large spike of
power to cause that flash/burn and melt the case?

lets wait and see ...?.....?......?

Brian - pulled this comment from the other thred running at the moment regarding MMM fire:

Originally Posted by BrianG

It can be. Personally, I would only use mechanical brakes in heavy vehicles and/or setups that use high voltage (6s+) because back-EMF generated during braking becomes considerable at higher voltages...

So are you guys saying that the EMF is causing the ESC's to fail prematurely? If so, should I be running mechanical brakes on 5s 6500mah Lipo's? If so, how do you assign reverse on a Spektrum DX2 to actuate the brake servo??? I'm all for it if it will stop the Monster failing again? Or are you recommending not running over 4S?

[Semi Pro]

Originally Posted by primus95

How many cells were you guys running when it smoked?

5 cell with a ccbec

when we all bought our v2's castle was still calling the bulletproof on 6cell so we went 5 cell so have alittle breathing room

[BrianG]

Originally Posted by primus95

Brian - pulled this comment from the other thred running at the moment regarding MMM fire:

So are you guys saying that the EMF is causing the ESC's to fail prematurely? If so, should I be running mechanical brakes on 5s 6500mah Lipo's? If so, how do you assign reverse on a Spektrum DX2 to actuate the brake servo??? I'm all for it if it will stop the Monster failing again? Or are you recommending not running over 4S?

I wouldn't call what I said "official", it's just my tendency to not run things to the max specs. I routinely run both my MMM systems on 5s with motor brakes and no problems so far.

I only run my 11lb truggy on 5s 5000mah zippy h 20 - 30c and have not had a single problem 13t 62t pinion spur.

[fastbaja5b]

I run my Savage Flux on no more than 4s, above that, and with such a heavy truck, I don't trust the ESC.

[primus95]

Originally Posted by BrianG

I wouldn't call what I said "official", it's just my tendency to not run things to the max specs. I routinely run both my MMM systems on 5s with motor brakes and no problems so far.

Thats fine mate, I know it can't be catergorised "official", but I know your a well respected member of the forum with a wealth of practical knowledge and I value your opinion.

I'm somewhat trying to get my head around why after doing all the reading, setting up my car how I considered "best practice", taking temps at multiple stages of the first run, I still blow the ESC in like 20 mins???

Would you consider my setup excessive or borderline or is it just "one of those things"??

If I gear down to 13/48 won't that just give me more torque and make the motor hotter?

Losi 8ight-T
MMM 2200Kv combo
14/48 gearing
Neu Energy 5S 6500mah Lipo

thanks

[fastbaja5b]

From what I read in the MGM article, even 5s may push the volts a bit too high under breaking, they used the example of a 6s set up on an 8s ESC, maybe we need such a high window such as run at 2/3 of rated capacity. IE run a MM at 2s not 3s and a MMM at 4s not 6s. They will run at 6s, sure, but the risk of failure especially under brakes would obviously be higher.

[e-mike]

i run all my mmm on 6 cell lipo no issue at alli kill 3 units but my issue was my 5 months old maxscrap 14,8 pack<<<