MMM killing motors? - RC-Monster Forums

Nephre · 05:39 PM

Anyone else that have had their motor ruined by the MMM?
I´ve got a MMM from the first batch that I thought worked fine untill today when it killed my third feigao. First it killed my 7XL in late may and I didn´t think anymore about it, Feigaos aren´t that great to be honest, they are cheap but the quality leaves more to ask. Ordered a Neu from CC, thought that I´would get myself something better and while I waited for it to show up I threw in another feigao I had laying around, an 7L. It lasted for about half an hour but I thought that since it´s not as strong as something from the XL-series, it probably died from the abuse, I don´t think the L-series are ment to be in such heavy cars as an 8th-scale buggy. After a while I got tired of waiting for the Neu (still haven´t got it) so a few days ago I got myself an 8XL that lasted for about three packs before it gave up on me in a trail of white smoke. First I thought it was the monster that died but after a quick investigation I realised that the smoke came from the 8XL.
Later this evening I checked the monster with a smaller motor, plugged it in and gave it some throttle. Everything seemed fine for about two seconds, then it started to cog and threw quite a lot of sparks and flashes at me. Holy mother of god, this can´t be right!! Well, I came to the conclusion that the monster probably killed all of my motors and I really don´t want to kill my Neu as well so I´m sending it back to CC, hopefully I´ll get a new one when the second batch is ready (when it comes to be serviceminded, CC kicks some serious butt

).
Anyone else that had similar problems? Or heard of anyone that had these problems?

Edit:
Sorry about my english, I´m from sweden and I guess that my english can be quite...swedish

e-mike · 05:24 PM

me too

had this problems....kill one 6xl and 7xl(reach 300f both motor

)totaly kill the magnet inside

do you have kill your mmm????

bdebde · 07.10.2008, 05:38 PM

It may not be the controller; what kind of temps did you have? You are checking temps on a new set up right? Any motor's magnet will die if you get it too hot.

Arct1k · 07.10.2008, 05:41 PM

I would just think that the MMM is letting the motor have all the amps it asked for whereas before you might have been throttled by the ESC.

I would check your gearing and double check your batteries as they must have been working hard...

07.10.2008, 05:47 PM

I have heard there is less resistance within a MMM than a MM so maybe that could be the case

Nephre · 05:52 PM

Quote:

It may not be the controller; what kind of temps did you have? You are checking temps on a new set up right? Any motor's magnet will die if you get it too hot.

Well, it was kind of high (very high in fact) but thats another strange thing about this. I´ve got two buggies now, recently got the other, a Mugen MBX5 Prospec, bought it from a guy here in sweden and a week later I bought his 8XL to, the very same motor he had used in this car and as far as I know he´haven´t had the temp getting over 60C/149F with the same gearing as I have. But when it died today it was so hot that you could fry an egg on it. Tried with some saliva and it just fizzed away

07.10.2008, 05:55 PM

Quote:

Originally Posted by Nephre

Well, it was kind of high (very high in fact) but thats another strange thing about this. I´ve got two buggies now, recently got the other, a Mugen MBX5 Prospec, bought it from a guy here in sweden and a week later I bought his 8XL to, the very same motor he had used in this car and as far as I know he´haven´t had the temp getting over 60C/149F with the same gearing as I have. But when it died today it was so hot that you could fry an egg on it. Tried with some saliva and it just fizzed away

it would be helpful if you give us more info...gearing,voltage of batteries, wheel size, etc

Nephre · 06:02 PM

Quote:

Originally Posted by azjc

it would be helpful if you give us more info...gearing,voltage of batteries, wheel size, etc

Mugen MBX5 Prospec
14/46
Polyquest 4s 4500mah 30-50c
Feigao 8XL
4.45" Wheels (basic 1:8th buggy wheels)

Thank for all the help by the way, I knew I could count on you guys

suicideneil · 07.10.2008, 07:18 PM

Make sure your mountng screws arent touching the windings inside the motor, as that will have rather negative results too...

ncnguyen123 · 07.10.2008, 09:34 PM

my MMM smoked my 8xl also. The 8xl was at 270 degrees when it died. I was running setup in gmaxx on 5s lipo.

I recently switched to the neu 1515 1y and motor has not run pass 170 degrees on same truck. I don't think it's the MMM that's smoking the motors. Like previous post, I think the MMM doesn't throttle back the amps to the motor so you really need to make sure your motor is top quality or you gear appropriately.

MetalMan · 07.10.2008, 10:30 PM

Surprisingly I had an issue with my Neu 1512 2.5D/F and MMM. At one point on the track it was cogging VERY badly at startup. Normally I would just go over to it and check out what was wrong, but the cogging was intermittent. When I finally took temps, my Neu was at 220 deg. F and the MMM was at 190! Normally that same setup would've been 160 for the Neu and ~140 on the MMM. I let everything cool down, and all was fine... I have no idea.

07.10.2008, 10:52 PM

Quote:

Originally Posted by MetalMan

Surprisingly I had an issue with my Neu 1512 2.5D/F and MMM. At one point on the track it was cogging VERY badly at startup. Normally I would just go over to it and check out what was wrong, but the cogging was intermittent. When I finally took temps, my Neu was at 220 deg. F and the MMM was at 190! Normally that same setup would've been 160 for the Neu and ~140 on the MMM. I let everything cool down, and all was fine... I have no idea.

when I ran the MMM for the first time I had the timing on the default setting which was set at 10 and the motor was between very warm and hot, I lowered it down to 0 and it gets a little warm after a 30 min bash session

What's_nitro? · 07.10.2008, 10:56 PM

All this talk about the MMM "not holding back the amps" is cracking me up.

Guys, you dont want an ESC to hold back. That makes it less efficient. It's true the MMM uses FETs with a much lower resistance than the MM does. Therefore the motor will draw more power. I think it's impossible that a controller can outright ruin a motor unless there is a problem with the programming that makes it cog like hell. Which you would obviously notice BEFORE it fried your motor and you would stop driving.....

Definitely make sure the motor screws aren't too long. That has been a common problem around here with the Feigaos. If all is well then just face the fact that Feigaos are cheap and if you overload them they will get really hot and fail. Done. The MMM is not at fault here.

auto2 · 07.10.2008, 11:18 PM

i had a 7 ( or 8 whoknows )xl in my xt8 with MMM on 4 and 5s with no problems. geared way too fast to race also.( ask mike lol) it did get hot though as I had to keep a fan on it.

traxxasrevony · 07.11.2008, 12:37 AM

hmm when my mmm worked it push my erevo on 4s to 53 with a 8xl on 20/38 and motor temps never hit 130 esc was 98 batts 97 and i was running talons then one shredded at 45. i was gonna try 22/38 to se if i could hit 58 but then the mmm failed.