ANOTHER Flux MMM goes up in flames!?
 

What say you Castle? This is starting to REALLY worry me. :gasp:

http://www.savage-central.com/module...81425&start=40

I don't understand the need to worry :neutral: There are so many MMM V3 speed controls out there that are fully functioning. My guess is he will be taken care of.

they are a great ESC...trouble is....newbies to the MMM world dont treat them like some others do.
they use NIMH batts and do high load monuvers:whip:

if only the info some of the veterans on here know was out there for the noobs to acces:oh:

I do not understand why people post this messages as they are a shame for Castle. In fact most of the times they are really just a shame for those users of Castle products.

When I started in this hobby, 35 years ago, playing with model airplanes, there was a rule, always learn from people with more experience.

Nowadays people look at videos in the internet, buy the equipments, use them as they think they should be used, instead of the way they must be used, and things happen.

There are already a lot of stories of "crazy" gear ratios. Of course it is easier to burn a ESC with 6 cells connected if the ratios are not what they should be.

Always look for an advise from a more experienced modeller. These things are not toys.

^^^ exactly!!
idealy...castle might have madea bomb proof ESC (less powerful that MMM maby) and sold that to traxxas and HPI...meh...who am i in the sceme of things :P
CASTLE FTW!!!!!

Come on 6s, 40 series big joes, geared for the moon and no airflow - Bugger all wholes in body and a sock over the esc!

...and what was up with that filter sock? Probably the root cause of his issue.

Nice sock to impede airflow, extremely heavy tires and wheels (I hate aluminum wheels BTW, what's the point?!), and an idiot who can't even type without cussing five times per sentence.

Looks to me stupidity is the recipe for disaster. Like the one poster said, all that money you could have gotten a data logger, or at least a temp gun. I also see he ran it for 40 minutes probably geared for 60 and going off road through tall grass.

I have beat the snot out of my V2 MMM on 6s and it always comes back for more. Then you have DickyT with 400 logged hours of hard use on his before it gave up the ghost. Not to mention all the other great success stories.

Edit: I also looked at the guys other posts where he tore the truck completely down and reassembled it. He could easily have missed something and has binding in the drive train as well.

this is the most useless thread that ive read....15lbs truck+no body air flow and kind of filter on the esc= this kind of failure....there should be have a CAUTION manual book in each box of flux or erby and newbe should read this manul before use the truck....

im not better than other guy's..o no:yes:...but i never melt a mmm like it in this way...

or simply make a software to prevent that...!!??

Well I plan on running Big Joe's 40 series as well, but I'm not sure if even going to attempt 6S power now and I've always kept my gearing 44/20 and i've leaned the power on the CC link and im running 28C SMC LiPos. Will I be ok?

Oh, and that "sock" is a special designed filter that MANY people uses without issues on their Baja's, so I fail to see how that could be even considered a possible cause of the fire

http://outerwears.com/categories.asp?cat=11441

And Jesus, dont' shoot the messenger. I'm a first time customer to CC, noobie to the brushless AND LiPo world who also spent ALOT of money on his Flux that he wants to protect. So i'm CONCERNED CUSTOMER and wanna prevent a tragedy like this so i'm asking the head hancho's themselves on who/what is at fault here so I don't become another failed/expensive noob RC statistic

6s is not the issue, people doing stupid things on 6s is.

A filter on a gas motor and a filter hindering airflow to an ESC is two different things.

You also cannot drastically increase the rotating mass on any vehicle be it nitro, BL, gas, or whatever and keep the same gearing setup. Everything is a trade off. You also don't want to run a monster truck geared for 60+ off road for 40 minutes straight with no cool off.

sorry...my last post can hurt someone:oops:,,,but we learn about each experience...so i think that you learn something...

6s lipo on the Savage really isn't for bashing if you ask me. 4s to 5s is best. If you gear down to compensate for the added weight and rotating mass it'll be fine. I run a MMM with an 80mm MedUsa in a ~16 pound Muggy and it's fine because I gear to compensate for the massive tires and the weight of the thing.

Outerwears on the Baja and the MMM are different. The Baja's flywheel is able to pull air through the filter very easily, the tiny fan on the MMM would have a harder time plus the filter will hold heat in.

So far it seems to me that you've been running yours within the safe limits of the power system and it has been fine. Running 6s with even stock gearing with wheels/tires that weigh 1+ pounds each is what will kill your ESC, Motor, and batteries.

So when I go to 40 series and maybe 6S, should I drop to 18 pinion?

try 18 tooth lowest timing,punch at 60% more airflow and check the temps:yes:

LOLOL, I like that filter thingy on the ESC! That noob shouldn't get a new MMM ESC by warranty...

What's stock pinion, 20T? I'd use BrianG's calculator and set a target speed of 35-40 MPH and measure your temps often. If your temps look OK then you can bump the pinion up a little.

Yah, its 44/20T. What calculator?

http://www.scriptasylum.com/rc_speed/_solver.html

I'm not sure that you really need a 12T pinion, perhaps a 15T to start with.

freezebyte-

I'm all for helping noobs. You've come to the right place if you want brushless advice.

However.... Your logic is flawed. You mentioned in your savage thread, for as much as you spent, you should just be able to take it out of the box and use it.

Well, these are toys, but they are the most highly technical toys I can think of. To think you can just pull it out of the box and use it.... well....the burnt mmm tells the story.

The failure was your fault, quite simply.

If you don't want it to break again stick around and read up. Best of luck.

Good god, a freaking 15T pinion just for getting bigger tires? Thats rediculous.

Uh newsflash if you reread the link, ITS NOT MY TRUCK.

Just run the numbers and see what it tells you. Dont forget to account for ballooning on those Joes - should be significant unless you tape the crap out of them. Just like putting bigger tires on a real truck, gotta gear down too if you want to keep your power. 99% of the "maroons" running 35's and 6" lifts dont realize that until its too late....they now have a gutless penis extension....

Might not be able to fit a 15T on the Flux - depends on how far you can adjust the motor.

It's physics, and it won't change no matter how much you hate it. It doesn't matter if you use CC, tekin, novak, or some other brand.

The heavier you get the truck, the more you need to gear down as well. It's not just wheel size but rotating mass and total vehicle weight as well.

His problem is a combination of stupid moves.

1. Heavier tires and wheels
2. Adjusting the EPA to limit speed
3. Putting a sock on the ESC
4. Not adjusting gearing
5. Not verifying that when he reassembled the truck that there was no binding

All of these combined for disaster.

Last note I will make is that anyone investing this kind of money into a high performance BL RC should spend the 15 bucks at least for a temp gun and monitor your setup constantly after any new changes.

Excellent points made by everyone here obviously. This is the best forum for technical advice.

I think 'attitude' has a lot to do with these problems as well... and it's partially the fault of the manufacturers such as Traxxas and HPI. Everyone seems concerned about the reliability of their setup after they burn six new holes in it. Well, you need to PLAN for reliability from the beginning and that means gearing your vehicle to a reasonable speed. Not some internet e-dick speed like 65.

40 MPH is damn fast for a 10+lb RC car. Have some humility and start with gearing that will get you to 40. If things work out, from there you can slowly try to work your way up in speed while monitoring the temps of your system.

Noob 0, laws of physics 1.

Its sad to see a toasted esc and then the person repsoncible blame everything and everyone else, including castle for the failure, really is. He probably saw the link to this thread and is now weeping his heart out- we're a horrid bunch, but its true; learn from the old guys and ask advice before making changes- these arent ToysRus vehicles after all....

i have that outwears filter on my sc8 as well but it was only because it was winter time and the track was muddy and wet....and i only used 4s....it helped to keep out the mud and my temps were ok (back to back 4s lipos runs of 17min each) but i definitely wouldn't use it if i was running 6s or 6s runs of 35+mins.....anyways...tell your buddy to check this site out..there is a TON of info about brushless and i only trust the guys on RCM if I have a question...rc-related or not :)

Well for one thing, the Flux motor isn't on that calculator nor the 40 series tires

Oh but it is, but it is- use the Neu 1515 1y 2200kv, as thats the motor the FLUX is based on (Castle licensed the Neu design and built it en mass since Neu couldnt possibly produce enough to fill demand). :mdr:

Ah ok, now I see them.

Hmm, i'm getting this with stock 44/20 with Big Joe 40 series with 4S at 4.2v fully charged

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 20
Total Voltage: 16.8
Motor KV: 2200
Tire Diameter (inches): 6.4
Tire Ballooning (inches): .2
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.2 : 1
Total Ratio: 16.12041 : 1
Tire Circumference (inches): 21.36 inches (542.62 mm)
Total Motor Speed: 36960 RPM
Vehicle Speed: 46.38 mph (74.51 km/h)
Effective KV Value: 2200
KT constant: 0.61 oz-in/A

Or at 3.7v

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 20
Total Voltage: 14.8
Motor KV: 2200
Tire Diameter (inches): 6.4
Tire Ballooning (inches): .2
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.2 : 1
Total Ratio: 16.12041 : 1
Tire Circumference (inches): 21.36 inches (542.62 mm)
Total Motor Speed: 32560 RPM
Vehicle Speed: 40.86 mph (65.64 km/h)
Effective KV Value: 2200
KT constant: 0.61 oz-in/A

Nope, try again- he said 6s lipo when he cooked his MMM right? and stock gearing?

I spy an epic fail on the person responsible's part... :yes:

No, thats for my future planned Flux setup, not his.

I'd try gearing for around 40mph to start, monitor temps, and then go from there.

Ah, I see. 50mph on 4s is a tall order for a truck that size- limit yourself to 40mph with only 4s, or step up to a 5/6s setup and gear accordingly- 50mph would be fine then, though the brand & quality of lipos is always key, as key as the gearing.

Its all good fun :smile:

I just wanna keep stock gearing is all on 4S. After all this, I don't think i'll ever touch 6S. I run SMC's 6000mAh 28C packs and soon their 9000mAh 28C's

So basically its showing me this with stock 44/20 gearing, 40 series Big Joe's and fully charged 4S at 4.2v

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 20
Total Voltage: 16.8
Motor KV: 2200
Tire Diameter (inches): 6.4
Tire Ballooning (inches): .2
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.2 : 1
Total Ratio: 16.12041 : 1
Tire Circumference (inches): 21.36 inches (542.62 mm)
Total Motor Speed: 36960 RPM
Vehicle Speed: 46.38 mph (74.51 km/h)
Effective KV Value: 2200
KT constant: 0.61 oz-in/A

And the same with the nominal 3.7v charge on 4S

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 20
Total Voltage: 14.8
Motor KV: 2200
Tire Diameter (inches): 6.4
Tire Ballooning (inches): .2
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.2 : 1
Total Ratio: 16.12041 : 1
Tire Circumference (inches): 21.36 inches (542.62 mm)
Total Motor Speed: 32560 RPM
Vehicle Speed: 40.86 mph (65.64 km/h)
Effective KV Value: 2200
KT constant: 0.61 oz-in/A



Looks safe to me

I'm yet to see a Flux esc go on 4s, but many on 6s because people read the manual, assume they need to "gear up" to a 25t pinion for 6s and then slap on some monster tyres.

I stopped running Nubz and Dirtbonez on my flux on 4s with stock gearing as it showed signs of being undergeared.

However the stockers and Terrapinz all fall within that safe 35-40mph range on stock gearing.

(Well the Terrapinz actually sit at 42mph and I don't see them balloon that often)

IIRC, adding voltage makes the amp draw go up unless you gear down. If you want to run those 40 series wheels with stock gearing on 4s try it but check those temps. If your ESC fan is coming on a lot, motor is getting too hot too fast, and your lipos are heating up beyond the safe limit (I consider 120 at the shrinkwrap to be the absolute hottest you want them to get) then you need to drop a few teeth.

Stock gearing, 6s lipo, 40 series, and WOT through grass you'll cook it in a matter of minutes. This may sound a bit complicated at first, but you've got to get your gearing dialed in a bit before you'll have the best reliability. On 4s lipo and 40 series I'd aim for about 35 MPH and keep temping it and go from there. Then you can step up to a 5s setup if you want more speed. Those wheels/tires weigh over a pound each so you're going to lose a lot of performance and I expect the lifespan of the differentials will be greatly reduced.

idiot.....i want to slap him really badly...............


then again...i can just go to the LHS and listen to the same thing....then slap them...i guess someones getting slapped twice at the LHS tomorrow:lol:

Just as an example Nubz tyres are 146mm and Dirtbonez are 150mm in Diameter, now I found these two to be undergeared in the Flux (high motor temp, low esc and battery temp) on stock gearing, and the Dirtbonez on stock gearing calculates at 35.45mph

Stock GT-2 tyres are 160mm (6.3 inches) to calculate at 37.856mph
HPI Terrapinz are 170mm (6.69 inches) to calculate at 40.199mph

All 3 fall within the safe 35-40mph range on 4s for the Flux on stock gearing, however my experience has shown that the Dirtbonez are a bit on the undergeared side and should go up to say a 22t pinion for 38.99mph

The set up you have shown that "blew up" may be fine on 4s Lipo (38.46mph) but on 6s Lipo it's out at 57.68mph stock gearing and a crazy 72.1mph on a 25t pinion if you take the manual as gospel (which it aint)

And that's not considering the extra weight your alloy bling rims throw in the mix.

Add in a sock over the esc which resticts air flow as the fan doesn't draw air in, merely circulates what is available, I'm not at all surprised it blew up!

I"ll take that chance, monster trucks are meant to have big ass tires. I refuse to believe that 2200kv will have a hard time powering 40 series wheels with the torque that thing puts out...