Engine problem

[bad.bomb9]

I recently bought two 5300mah 2s lipo to use with stick 3903 emaxx. Ive been through about 4 packs without problem. I was running the truck today and noticed a burning smell when it drove by me. I popped off the body and found this:

http://s1208.photobucket.com/albums/...t=IMG_1334.jpg
http://s1208.photobucket.com/albums/...t=IMG_1331.jpg

Two pieces of metal, melted out of what Im guessing the engine, one piece almost melted through my chassis while the other melted through the hardcase lipo. It did not penetrate the cell from the looks of it, but im still scared to charge it. The engine was hot to the touch after I took the cover off, but It wasnt hot enough to take your hand away from it. It was about 31F (0C) outside.
What happened? and How could I fix this??

[chestnutjazz]

What's your gearing set up? It seems like your motor is running way too hot!!!

[bad.bomb9]

The gearing is stock (17/68). To me it looks like one of the sets of brushes on the motors completely melted off while the other set just deformed. I just tried using stock Nimh batt, the motors do not move at all. I think both of the 550s are completely dead.

[ArmyofDarkness]

Curse of the 550 titans; some people have great luck, others complain that the brushes fall apart after a few runs; guess which camp you fall into...

Traxxas should warranty those motors, though I wouldn't bother- there are lots of other options for much better quality motors these days ( dewalts, banebots, hpi gt550s etc ). I would leave your lipo in a safe place over night & then check the voltages the next day- if that cell is damaged it will have swollen or the voltage will be out of whack compared to the others. Remove the melted brushes carefully and inspect underneath to make sure the foil casing of the actual cell isnt pierced, then do a normal charge with the packs in a fireproof bag or metal tin etc.

[bad.bomb9]

I was thinking of going the dewalt way, but ive heard those don't last too long on lipo either but I like the price ($30-40). I've been eyeballing the twin vxl and the mamba monster with 2200kv setup for a while now. I'm just not too happy with what I have to spend on one of them. I would love to have something below the $300 mark. I am looking for something thats snow proof. Ill be checking on lipo later tonight, if somethings wrong with it, hopefully my lhs could replace it.

[ArmyofDarkness]

MMM&2200kv motor system can be had for $250 if you shop around- dual vxl system is actually about the same give or take.
There are numerous other options for a smaller budget- hobbywing 150amp XErun systems are quite nice for example, but aftermarket support isnt so great ( depends where you buy it really ). Have a look at this thread for some ideas:

http://traxxas.com/forums/showthread...shless-systems

[bad.bomb9]

I'm thinking the MMM and 2200kv. Ive read other places that it's a pain to get the two vxl motors to be in pefectly in sync. How would the MMM and 2200kv do with with two 25c 2s 5300mah lipos?

[ArmyofDarkness]

35-40mph with standing & rolling backflips sound fun? ( 24/68 or 18/54 gearing required- stock 18/68 is very tame on 4s lipo ).

Ideally I recommend 30c or higher batts in 5000mah capacity to most guys, but what you have there should still be fine, just check temps during the run(s):

esc & motor = 180*F max, ideally below 160*F
lipos = 140*F max, ideally below 120*F

[bad.bomb9]

Where would be the best place to buy the 2200kv combo?? The Traxxas powerup program has it for $250 and it looks like it comes with everything. Amazon has just the esc and motor for about $240. Would I need a new motor plate or could I just use the stock one and cover the other hole?? Thanks.

[TRXmaxximum]

badbomb, you are definately headed in the right direction! I have the MMM2200 in one of my e maxxes and it is far beyond ANY brushed setup! And I have run a boatload of brushed setups over the last 7 years in 3 different e maxxes.

[bad.bomb9]

Thanks for your previous post! The battery wasn't rubbing up against the motor. It was sitting in the battery compartments, kind of a tight fit, but it works. One titan 550 pretty much exploded inside while the other one doesn't work anymore. Traxxas said that they have no warranty for "double motor failure", so I'm gonna have to shell out some $$ on something.

[ArmyofDarkness]

No warranty for double motor failure? That is rather lame; maybe phone them up again & say one motor failed, get a new one, then phone up a day later ( get a different phone rep ) and say the other failed, lol. If they spent more than a buck per motor from their OEM source ( marabuchi I think, or one of those kind of companies ) then they wouldn't have so many failures & warranty claims- they are making a rod for their own backs as the saying goes...