#3 MMM not dead YET, but something VERY wrong!
 

So I installed the latest MMM, hooked it all up and was cruising it around the basement. Was running fine.. obviously.. nothing high speed.
But then.. something started acting up... at first.. then it got worse...
When you hit the throttle, forward or reverse, it just stutters... It's like it isn;t sure which direction to go? Does it in both forward and reverse. Tried disconnecting the batts and resetting... Same. Tried another set of batts.. Same. This is very similar to what the previous MMMs did before just stopping.
I am running an e-revo, 1515 1.5d, 4s TrueRc 8A, Novak BEC with red wire cut on the MMM.
Could it be the NEU? I have a medusa, but I have to solder connectors, before I can try to determine if it is the motor.

Anyone with any ideas? I plan to call CC in the AM and talk to them. If this one is half alive, I'd like to let CC look at it before it's dead.

Could it be a loose solider joint?

I checked all solder joints.. I think...
Do you mean like a loose solder joint that is wiggling?
This isn't like it is stuttering forward.. It's stuttering forward/reverse, thus no movement in either direction. Almost like the polarity is switching rapidly...
AND no more MMM TONES!

Not to Jinx you but my modded V2 started doing this before it....(you know what)... :intello:

I hope its just a bad solder or lose connection....

let us know

It's what my previous 2 did as well... But I think that failure point was much shorter because the rig was in motionat a much faster rate, maybe?

My guess is bad solder between motor and MMM. Check the bullets comming off of the motor.
Go on a high speed blast, should get pretty hot pretty quick.

Sometimes the bad connection wont wiggle.I have a 1512 1.5d and had bad cogging and the MM was real!! hot after just a few minutes.I ended up redoing all my connections and after that all was good.Now when I solder any RC I allways double check all connects.Also the MMM V2s wires are so heavy that its hard to get the solder to melt.

I can't.. It won;t move.. It just jerks.. it is a rapid stutter and as much forward movement, there appears to be the same reverse movement.
It's not a forward/stop/forward/stop stutter.

check the connection from the wires into the male 6.5's known to cause problemss

I would resolder all your connections between esc and motor. It sounds like either a bad esc or solder joint but the only way to tell is to resolder everything.

Yes guys, double, triple, even quadruple check your soldering connections. It is very difficult to get those 8 AWG wires from the MMM to solder to connectors. I have a 40W iron and it takes me about 90 seconds of heat to get the solder to flow appropriately. If you do not get both pieces of metal hot enough to melt the solder you will end up with what is called a 'cold solder'. Sometimes you can tell by the fact that the joint will look hazy rather then nice and shiny. A cold solder can lead to high resistance and cause lots of problems including extra heat. I still have a v1 first batch running strong, but I have soldered many, many times.

I am sure many know this, but you heat the metal, then apply the solder to the metal, NOT the iron.

Yea.. I hear what you are saying.. I have been soldering crap longer than I was ever in school and in the service.
I'll reflow everything tomorrow.

I have a mini brushless system that is doing the same thing and I have narrowed it down too a loose wire on the motor , if I press on it it will run fine till it vibrates loose .

BTW , this is going into the can , not at the connectors .....

Well there's your problem! </mythbusters> :lol:

I use an 80w iron with a big honkin' chisel tip. That shows those connectors who's boss in just a few seconds. :yes:

i have a 40w 5$ harbor freight deal. thing works awesome! gets real hot! i cant believe it

if you disconnect one motor wire you will get exactlly the same thing soooooo... hope for a bad joint

Exactly my thoughts. If it's not a poor solder connection and all the MMM's FETs are intact, then next item to question would be the motor :whistle:

Just an idea here. Any of you guys with the stuttering/cogging controllers have a second motor you could connect to the controller to make sure that it really is the ESC that is having problems?

Doesn't have to be a motor capable of driving your car, just any brushless motor...

I just had a situation with a setup where one of the motor wires had come loose inside the motor can. Everything looked great, motor just waggled when power was applied. Tested OK when we pulled it out of the vehicle, but a little tug here and there and the wire came loose.

If a setup doesn't work multiple times, I mean with multiple Monster controllers, start looking for another point of failure. We really do test these things before they leave the shop.

Lee

Wow this is awesome Castle Creations is adding new members to the forum who are Tech gurus! Thats freakin sweet!!!!!!!!!!!!!!!!!!!!!Thanks

lol, pretty soon, we're gonna have their whole staff here! :smile:

What motor is it ? Check that motor screws aren't shorting against the windings. That can produce exactly the symptom you describe, and can make short work of the ESC.

The more knowledge the better!

OK.. So I tore down all my solder joints... I think I have more burns and blisters on my fingers now than I did in 8 years working on Navy Electronics. :)
It fixed the issue. I think it was the solder joints of the Bullet connectors and the massive wires out of the NEU.
I did try the previous failed MMM and it is still not responding.

I think the issue is that lead free solder that just needs so much heat to flow.

Thanks to all of you guys that chimed in.

Then work will be limited since most of them will be in the forum :lol::lol:.

Did you re-solder the castle pre-assembled bullets also?

I read in another thread a guy who had a cold solder joint on one of the castle fitted 6.5mm male bullets.
Just wondering if faulty solder joints are to blame for some of the MMM failures?

Cold solder joint on the motor side causing the speed control to over heat and letting the smoke out??

Cold solder joint on battery side causing some BEC issues???

I know it wouldn't explain all failures but could it be contributing???

I used new wires from Castle from one of my new MMMs. So they did get changed out, just not re soldered by me.

Iam glad you found the problem.I guess this is a good example to point out problems that a regular guy can fix.As for burnt fingers I work as a Chef and basicly have tempered fingertips.Why lead free solder?

That's what they tinned the NEU wire ends with. Wires are short enough that I didn;t want to cut them. Seems most are using lead free now. It's a good thing, but add the extra heat for teh lead free solder on top of the massive wires for the NEU AND the 6.5 bullets... I can see how it happened.

It's a requirement for electronics sold in Europe, and it's just plain good practice for companies.

That said, I use Radio Shack 60/40 leaded solder :lol:. But I make sure to wash my hands before eating after handling that stuff...

That eyeball on your avatar kinda makes me sick to my stomach! Kinda trippy.

Glad you found the problem. 9 out of 10 its mechanical. .9 of the rest is somewhere in power, and only the .1 last is something really wrong with a component.